Paul Bizimana

• 21 December 2021
• Time: 5 PM - 7 PM.
• PhD defence
• Supervisors: Prof. JP. Van geertruyden, dr. K. Polman and dr. G. Ortu

Abstract

Schistosomiasis is a major public health problem in the world, especially in (sub)tropical countries. It affects more than 78 countries in the world, of which more than 90% are in sub-Saharan Africa. Linked to poverty, its consequences are of great importance for individuals, households, communities and countries. In Burundi, the disease is known for several decades. Only S. mansoni is endemic in the country. The control of the disease relies on yearly mass drug administration (MDA) campaigns of praziquantel to school-age children from 2008, in which health centres (HC) are involved. With MDA, the prevalence decreased substantially from 12.7% (2007) to 2.2% (2014). The main objective of this thesis was to explore the capacities of Burundi to integrate schistosomiasis control into the primary health care (PHC) system at HC level, by providing evidence-based recommendations for the integration of schistosomiasis case management, disease surveillance and other schistosomiasis control activities, namely health education, snail control, clean water supply and sanitation. The integration of schistosomiasis case management in the routine activities of HC requires the improvement of health care providers' knowledge - in charge of consultations and patient referrals - and.the availability of praziquantel. Despite the obvious shortcomings, routine monthly reporting from HC to Directorate of National Health Information System of intestinal schistosomiasis cases after confirmation by direct smears of stools, appeared to be able to monitor the impact of MDA with praziquantel in the general population; therefore, it could be used as an indicator for the disease surveillance in the country. However, more sensitive tests are recommended and desirable, such as the point-of-care Circulating Cathodic Antigen (POC-CCA) test, especially in low endemie settings such as Burundi and in view of the country schistosomiasis elimination goal. For the integration of the four remaining activities beyond case management at the HC level, only health education appears to be the most feasible prevention and control activity, but not the others, as they require the (technica!) involvement of other sectors beyond the ministry of health and international financial support which may not be available/sustainable in Burundi, to be fully implemented.

Mariska de Lausnay

• 16 December 2021
• Time: 4 PM - 6 PM.
• PhD defence
• Supervisors: Prof. S. Verhulst and prof. K. Van Hoorenbeeck

Abstract

Down syndrome (DS) or trisomy 21 is a prevalent chromosomal disorder that is associated with a broad spectrum of health problems, such as developmental and cognitive delay, hypotonia, hearing loss, refractive errors, heart defects, gastrointestinal anomalies, autoimmune disorders, and so on. Besides the well-known upper airway problems, including recurrent otitis media and obstructive sleep apnea, we also noticed that children with DS often suffer from lower airway problems (both infectious and non-infectious). These impose a major health burden on both the patients and their families, though studies about this topic are scarce. In this dissertation, we provide a systematic overview of the different pulmonary and airway problems encountered in this specific patient population, and explore certain topics in more detail in an attempt to provide a more patient-tailored clinical approach. More specifically, we investigate the prevalence of airway anomalies, their effect on obstructive sleep apnea, the lower airway microbiota, the use of immunological parameters in predicting recurrent infections and whether we can improve the detection of chronic pulmonary aspiration in a large cohort of children with DS.

Jean-Baptiste Belge

• 14 December 2021
• Time: 4:30 PM - 6:30 PM.
• PhD defence
• Supervisors: Prof. D. Schrijvers, prof P. Sienaert, em.prof B. Sabbe and dr. L. Van Diermen

Gitta Boons

• 13 December 2021
• Time: 5 PM - 7 PM.
• PhD defence
• Supervisors: Prof. M. Peeters, prof. G. Van Camp and prof. K. Op de Beeck

Abstract

Neuroendocrine neoplasms (NENs) are malignancies that develop from neuroendocrine cells present in various organs throughout the human body, including pancreas, small intestine and lung. They are historically considered rare, but their incidence has been increasing over the past decades. An important unmet medical need are good, preferably blood-based, biomarkers that can assist in the clinical management of NEN patients. Advances in next-generation sequencing and other high-throughput technologies have accelerated the molecular research in NENs. Newly identified molecular alterations could therefore provide a novel and interesting source of biomarkers for NENs and warrant further study. In this PhD project, we have therefore explored the genetic and epigenetic landscape of NENs with the general aim of identifying both tissue and liquid biomarkers. In a proof-of-concept study, we first examined the presence of circulating tumor DNA (ctDNA) in plasma of pancreatic NEN (PNEN) patients using mutation and copy number alteration profiling. In a follow-up study, the biomarker potential of ctDNA was further explored in a larger cohort of gastroenteropancreatic and lung NEN patients of which longitudinal plasma samples were collected. In the last part, the epigenetic landscape was studied, and more specifically the genome-wide DNA methylation profile of PNENs. Thereby, PDX1 DNA methylation was studied as a biomarker for PNEN subtyping.

Elyne De Baetselier

• 10 December 2021
• Time: 6 PM - 8 PM.
• PhD defence
• Supervisors: Prof. B. Van Rompaey en prof. T. Dilles

Abstract

Het doel van dit doctoraatsonderzoek was de rol van verpleegkundigen in farmaceutische zorg te onderzoeken in 14 Europese landen, vervolgens een raamwerk over deze rol te ontwikkelen en te evalueren en tenslotte competenties te onderzoeken die verpleegkundigen nodig hebben om deze rol te vervullen.

Een eerste studie bij 4888 verpleegkundigen, 974 artsen en 857 apothekers toonde dat de meeste gezondheidswerkers de Verpleegkundige betrokkenheid in farmaceutische zorg wilden uitbreiden. Deze bevindingen werden uitgediept aan de hand van 340 interviews. Meerdere verpleegkundige farmaceutische zorgtaken kwamen naar voor. Ondanks ambivalentie over de implementatie ervan, kregen verpleegkundigen een actieve rol toebedeeld. Respondenten meldden een positief effect op kwaliteit van zorg en patiëntuitkomsten wanneer verpleegkundigen farmaceutische zorgverantwoordelijkheden op zich namen. Enige nuancering is hierbij van belang. De mate van verpleegkundige autonomie wordt namelijk bepaald door de context, gaande van geen autoriteit over beperkte verantwoordelijkheid tot een breed scala aan taken en verantwoordelijkheden. Bij het vertalen van de ideale rol van verpleegkundigen naar de klinische praktijk moet rekening worden gehouden met opleiding, teamkenmerken, landspecifieke regelgeving en soorten geneesmiddelen waarvoor verpleegkundigen verantwoordelijk worden gesteld.

Een scoping review werd uitgevoerd om de bestaande lijst met verantwoordelijkheden en taken aan te vullen. In totaal werden zeven verantwoordelijkheden geïdentificeerd: management van therapeutische en neveneffecten van geneesmiddelen; management van medicatietrouw; management van medicatie-zelfmanagement door patiënten; management van patiënteducatie/informatie over geneesmiddelen; voorschrijfmanagement; management van medicatieveiligheid; en zorgcoördinatie. De uitgebreidheid van verpleegkundige activiteiten - 26 taken werden beschreven binnen deze zeven domeinen – toonde aan dat verpleegkundigen sleutelfiguren zijn in farmaceutische zorg. Deze scoping review ondersteunde de ontwikkeling van het NUPHAC-EU-kader, waarin potentiële verpleegkundige farmaceutische zorgtaken worden beschreven, samen met mogelijke barrières en bevorderende factoren. Na de ontwikkeling van het kader werd de inhoud geëvalueerd door 923 verpleegkundigen, 240 artsen en 199 apothekers. 'Gedeelde verantwoordelijkheid' bleek het meest geprefereerde niveau van verantwoordelijkheid.

Tot slot werd in een Delphi-studie een competentiekader ontwikkeld dat gebruikt kan worden in competentiegericht onderwijs om de integratie van farmaceutische zorggerelateerde competenties in verpleegkundige curricula te evalueren of om onderwijsprogramma's te herontwerpen opdat verpleegkundestudenten adequaat voorbereid zijn op de klinische praktijk.

De toekomst van het NUPHAC-EU-kader en het competentiekader zal afhangen van de evidence-based implementatie ervan in het verpleegkundig onderwijs, interprofessioneel onderwijs en de klinische praktijk. Dit proefschrift biedt zorgverleners, docenten Verpleegkunde, onderzoekers en beleidsmakers handvaten om samen, en met gedeelde focus op wat best is voor de patiënt, toe te werken naar meer interprofessionele, geïntegreerde, evidence-based farmaceutische zorg.

Christiaan Heusdens

• 26 November 2021
• Time: 2.30 PM - 4.30 PM.
• PhD defence
• Supervisors: Prof. F. Van Glabbeek, prof. P. Van Dyck and prof. P. Verdonk

Abstract

De voorste kruisband (VKB) is een belangrijke stabilisator in de knie. De VKB voorkomt het te ver naar voren bewegen van het onderbeen (tibia) en draagt ook bij aan de rotatoire stabiliteit van de knie. VKB rupturen zijn de meest voorkomende band letsels van de knie. De gemiddelde leeftijd waarop iemand zijn VKB scheurt is ongeveer 34 jaar. Een gescheurde VKB kan op drie manieren behandeld worden. Ten eerste conservatief: met behulp van een kinesist (fysiotherapeut) worden de spieren en stabiliteit van de knie opgetraind, waarna 50% van de patiënten geen instabiliteitsklachten ervaart. De andere 50% met blijvende instabiliteitsklachten, evenals sporters die veel draai (rotatoire) bewegingen maken, zullen met een operatie behandeld worden. Ten tweede, met de klassieke operatieve behandeling; de reconstructie. Hierbij wordt een hamstringpees (andere pezen zijn ook mogelijk) uit dezelfde knie ‘geoogst’ en teruggeplaatst op de plaats van de gescheurde VKB. Ten derde is het operatief ook mogelijk om de VKB te hechten/ herstellen. Voor deze techniek is geen andere pees nodig. Het onderste deel van de gescheurde VKB wordt tegen het bovenste deel gespannen met een hechting. Naast de gehechte VKB wordt een ‘veiligheidsgordel’ gespannen, die gedurende de genezingsperiode van de VKB, de gehechte VKB beschermt als er te veel kracht op komt te staan.

VKB herstel operaties werden in de jaren ‘70 al uitgevoerd, alleen de resultaten bleken destijds tegen te vallen. De VKB reconstructie werd de standaard operatieve behandeling van een gescheurde VKB. VKB reconstructie is een goede operatieve behandeling, echter er kleven ook nadelen aan. Enkele voorbeelden; 39% van de patiënten krijgt een complicatie, binnen 2 jaar heeft 6% een re-ruptuur (in hoog risico groepen zelfs 28%), patiënten ervaren nog pijn rond de knieschijf (20%) en bij knielen (15%), geen goede rotatoire stabiliteit (24%), de revalidatie duurt 9-12 maanden en maar 50-65% van de amateur sporters haalt zijn oude niveau weer en er blijft een verhoogde kans op artrose (slijtage). Er is ruimte voor verbetering. 

Recent zijn moderne VKB herstel operatietechnieken geïntroduceerd. De theoretische voordelen hiervan zijn; de operatie is minder invasief, het behouden van de eigen VKB met de zenuwcellen (proprioreceptoren) die bijdragen aan de stabiliteit waardoor de revalidatieperiode verkort kan worden, er hoeft geen pees ‘geoogst’ te worden, mogelijk beschermt het tegen de verhoogde kans op artrose en indien een re-ruptuur optreedt kan een klassieke VKB reconstructie worden uitgevoerd (‘no bridges are burned’).

De bedoeling van deze thesis is om een bijdrage te leveren aan de discussie of deze moderne VKB herstel technieken een behandelingsoptie kunnen zijn voor patiënten met een acuut gescheurde VKB.

In hoofdstuk 2 wordt beschreven hoe een VKB herstel operatie uitgevoerd kan worden met de ‘Suture Tape Augmentation’ (STA) techniek. Samen met de ontwikkelaar van deze techniek, professor Gordon MacKay, hebben we de STA techniek uitgelegd met begeleidende foto’s, tekeningen en video.  De voor- en nadelen, evenals adviezen worden gegeven. Deze beschrijving helpt andere orthopedisch chirurgen als zij met de nieuwe STA techniek willen starten.

De resultaten van professor Gordon MacKay zijn eerste 42 patiënten die hij behandeld heeft met de STA VKB techniek worden beschreven in hoofdstuk 3. Dit artikel is de eerste studie waarin de resultaten van patiënten met de STA VKB techniek met een twee jaar opvolging beschreven worden. De patiënten hebben een betekenisvolle verbetering op verschillende kniescores en 4.8 % heeft een re-ruptuur. Uit deze studie blijkt dat STA VKB herstel techniek klinisch relevant kan zijn voor patiënten met een acute, niet verschrompelde en uit goed weefsel bestaande VKB ruptuur.

In hoofdstuk 4 beschrijven we de resultaten van de eerste 35 patiënten die we zelf in het Universitair Ziekenhuis Antwerpen (UZA) hebben behandeld met de STA VKB herstel techniek met twee jaar opvolging. In deze studie beschrijven we dat de patiënten weer een stabiele knie hebben gekregen (gemeten met de rolimeter), de patiënten hebben gunstige kniescores, 50% is na 5.5 week weer aan het werk en 50% is binnen 6 maanden weer aan het sporten. Een re-ruptuur kwam voor in 11.4% van de patiënten en 8.6% kreeg een heroperatie voor een andere reden dan re-ruptuur. Patiënten met een hoog sportniveau (Tegner ≥ 7) en patiënten die op de MRI na 6 maanden geen goede genezing tonen (‘grade 3 ACL healing’) hebben een verhoogde kans op een re‑ruptuur. Met deze kennis kan in de toekomst beter patiënten geselecteerd worden die in aanmerking komen voor de STA VKB herstel techniek. Concluderend toont deze studie aan dat de behandeling van de acute, herstelbare VKB ruptuur met de STA techniek leidt tot een stabiele knie, gunstige kniescores, echter het re-ruptuur risico van 11% is een zorg.

De dynamische intraligamentaire stabilisatie (DIS) techniek is een andere moderne VKB herstel techniek. In 2014 hebben we deze techniek voor het eerst toegepast in het UZA. Als een arts met een nieuwe techniek begint, zijn er vaak “opstart problemen”. In hoofdstuk 5 worden de ervaringen en resultaten van onze eerste DIS patiënten beschreven. We hebben een nieuwe patiëntenstroom moeten ontwikkelen, aangezien deze patiënten binnen 3 weken na de ruptuur geopereerd moesten worden. Het nieuwe instrumentarium, hechtdraden management, postoperatieve problemen en MRI interpretatie zijn voorbeelden van ‘problemen’ waarmee we ervaring hebben opgedaan. ‘Tips and Tricks’ worden gedeeld, die andere orthopedisch chirurgen kunnen helpen die met de DIS techniek starten.

Elahe Kazemeini

• 22 November 2021
• Time: 9 PM - 11 PM.
• Online defence
• Supervisors: Prof. O. Vanderveken, prof. M. Dieltjens and dr. S. Op de Beeck

Abstract

Obstructive sleep apnea (OSA) is a multifactorial disease with individual expressions, so there is not one therapy or diagnostic tool that fits all subjects. There is a need for a personalized approach in both diagnosis and treatment of OSA. Precision medicine management of OSA is the next step forward in improving care, reducing costs and avoiding unfavorable side effects and comorbidities. The primary aim of this thesis was to improve the overall effectiveness of OSA treatment, in particular mandibular advancement device (MAD) treatment. In this thesis this was achieved on three different levels, to increase both MAD treatment adherence and efficacy. First, we could validate and introduce the checklist individual strength questionnaire (CISE20R) in OSA patients. This questionnaire allows a thorough follow-up of the evolution in fatigue as perceived by the patient. As reduction in fatigue has been shown to be associated with MAD treatment, this questionnaire can play an important role in optimizing MAD treatment adherence. Second, MAD effectiveness can be improved by increasing MAD efficacy. Efficacy of MAD treatment is affected by both titration and upfront patient selection. Regarding titration, we showed the non-inferiority of the use of a remotely controlled mandibular positioner (RCMP) during drug-induced sleep endoscopy (DISE) compared to subjective titration and RCMP during DISE, as such fastening and objectifying the titration protocol. The upper airway collapsibility has been shown to be associated with MAD treatment outcome. In the current thesis we showed that it is feasible to perform concomitant site, pattern and degree of collapse assessment during DISE and critical closing pressure (Pcrit) measurement, getting one step closer towards Pcrit assessment in routine clinical practice.

Diana Campillo Davó

• 8 November 2021
• Time: 5 PM - 7 PM.
• PhD defence
• Supervisors: Prof. V. Van Tendeloo and prof. E. Lion

Abstract

Genetic engineering of T cells for adoptive cell transfer has marked a turning point in personalized immunotherapy, especially in the treatment of cancer. This strategy focuses on specifically targeting tumor-associated antigens (TAAs) by modifying T cells with immune receptors, such as T-cell receptors (TCRs), to improve T-cell ability to detect and eradicate tumor cells. T cells express TCRs that recognize short peptides derived from the intracellular processing of proteins. These peptides are bound to molecules of the major histocompatibility complex (MHC) and presented on the cell surface as peptide-MHC complexes. Thus, in TCR-engineered T (TCR-T)-cell therapy, T cells are engineered with nucleic acids containing the genetic information of TCRs derived from tumor-specific T-cell clones that specifically target peptides of TAAs. TCR-T-cell therapy has achieved extraordinary results in solid cancers like melanoma; however, the development and use of TCR-T cells in the clinic for the treatment of hematological malignancies has been challenging and it is still unsatisfactory. In particular, acute myeloid leukemia (AML) is an aggressive type of blood cancer and one of the most common types of leukemia in adults, especially in those older than 65. Relapse rate in AML patients after standard of care is 80% and current rate of survival for relapsed patients is no higher than 10%, warranting the development of improved and safe therapies for this malignancy. This thesis explores the use of RNA electroporation as a non-genotoxic strategy to redirect T-cell specificity towards an AML antigen named Wilms’ tumor 1 (WT1), as well as the parameters involved in increasing TCR-engineered T-cell-mediated tumor cell recognition.

Tineke Dilliën

• 3 November 2021
• Time: 4 PM - 6 PM.
• PhD defence
• Supervisors: Em.Prof. B. Sabbe and prof. K. Goethals

Abstract

Daders van seksueel kindermisbruik worden gekenmerkt door problemen in het reguleren van hun gedrag. Deze gedragsregulatie problemen worden in verband gebracht met het ontstaan en het voortbestaan van hun delictgedrag. In overeenstemming hiermee, is het vergroten van gedragsregulatie een zeer belangrijke doelstelling in de behandeling van daders van seksueel kindermisbruik. Tot op heden zijn de gedragsregulatie problemen en de mechanismen die aan de grondslag liggen van deze problemen echter onvoldoende begrepen, hetgeen het moeilijk maakt om gerichte behandelingsstrategieën te ontwikkelen om de gedragsregulatie te verhogen. Dit proefschrift heeft daarom tot doel onze kennis over de mechanismen die aan de grondslag liggen van de gedragsregulatie moeilijkheden te vergroten. Hierbij baseerden we ons op de ideeën van Ward en collega’s die aanraadden om de factoren die bijdragen tot seksueel delictgedrag te begrijpen in termen van neuropsychologische processen.

Waar de nadruk tot op heden lag op executieve functies bij het bestuderen van de neuropsychologische grondslagen van de gedragsregulatie problemen, werden in dit proefschrift de mogelijkheid tot bekrachtigingsleren en de mogelijkheid tot affectherkenning bij daders van seksueel kindermisbruik bestudeerd. Deze processen zijn cruciaal voor het inhiberen van ongewenst gedrag en werden omwille van deze reden uitgebreid bestudeerd in de algemene forensische literatuur. Bekrachtigingsleren is het proces waardoor mensen verbanden leggen tussen hun gedrag en de gevolgen van hun gedrag en hun gedrag aanpassen in functie van deze gevolgen die als bekrachtigers fungeren. Gedrag dat geassocieerd wordt met gewaardeerde uitkomsten (beloningen) zal herhaald worden, terwijl gedrag dat geassocieerd wordt met negatieve uitkomsten (straffen) onderdrukt zal worden. Het herkennen van emoties op gezichten speelt eveneens een belangrijke rol in het reguleren van het eigen gedrag omdat emotionele gezichtsuitdrukkingen als bekrachtiger werken op basis waarvan individuen hun gedrag aanpassen. Waar het vertonen van positieve gezichtsuitdrukkingen het gedrag dat aanleiding geeft tot deze emoties zal versterken, zorgen tekenen van angst en verdriet ervoor dat het gedrag dat deze emoties oproept, geremd wordt.

Waar beide processen tot op heden slechts in zeer beperkte mate aandacht kregen in de literatuur over seksuele daders, toont het onderzoek in dit proefschrift duidelijk aan dat de neuropsychologische grondslagen van de gedragsregulatie moeilijkheden van daders van seksueel kindermisbruik

niet beperkt zijn tot executieve dysfuncties, maar ook moeilijkheden in bekrachtigingsleren en affectherkenning omvatten. Deze resultaten laten toe een aantal nieuwe behandelmogelijkheden te schetsen die toegevoegd kunnen worden aan de traditionele daderinterventies om aldus tot een effectievere behandeling van daders van seksueel kindermisbruik te komen.

Anke Verlinden

• 26 October 2021
• Time: 4:30 PM - 6:30 PM.
• PhD defence
• Supervisors: Prof. W. Schroyens and prof. A. Gadisseur

Jinthe Van Loenhout

• 21 October 2021
• Time: 5 PM - 7 PM.
• PhD defence
• Supervisors: Prof. E. Smits, Prof. A. Bogaerts and C. Deben (PhD)

Lore Dams

• 14 October 2021
• Time: 6 PM - 8 PM.
• Joint PhD defence
• Supervisors: prof M. Meeus, prof N. Devoogdt (KULeuven)

Vasiliki Siozopoulou

• 19 October 2021
• Time: 5 PM - 7 PM.
• Public defence
• Supervisors: prof. P. Pauwels, prof. E. Smits and dr E. Marcq

Marjolein Orije

• 15 October 2021
• Time: 5 PM - 7 PM.
• Public defence
• Supervisors: Prof. E. Leuridan, prof. P. Van Damme and prof. B. Ogunjimi

Abstract

Vaccination during pregnancy augments the disease-specific maternal antibodies, which will be successfully transferred to the fetus in utero, and later to the newborn via the breast milk. Both the transferred and breast milk antibodies help to protect the newborn against the targeted pathogen up till several months after birth. Next to a protective effect, maternal antibodies have been observed to interfere with (or modulate) the infants’ antibody responses at the time of the infants’ vaccination, often resulting in significantly lower antibody concentrations amongst infants born to vaccinated mothers. However, it remains unclear whether this maternal antibody modulation has any impact on the equally important cellular immune responses. This thesis further explores the benefits of maternal pertussis vaccination in preterm born infants and illustrates the modulatory effects of high maternal antibodies on the humoral and cellular immune responses after the infants’ primary and booster vaccination.

Isabel Witvouwen

• 30 September 2021
• Time: 3.30 PM - 5.30 PM.
• PhD defence
• Supervisors: Prof. H. Heidbuchel and prof. E. Van Craenenbroeck

Annemarie van der Wal

• 27 September 2021
• Time: 3 PM - 5 PM.
• Public defence
• Supervisors: Prof. W. De Hertogh, em.prof. P. Van de Heyning and prof. S. Michiels

Niels Van Regenmortel

• 23 September 2021
• Time: 5 PM - 7 PM.
• Public defence CDE aula O8
• Supervisors: Prof. P. Jorens and prof. T. Van den Wyngaert

Elien Van der Gucht

• 22 September 2021
• Time: 6 PM - 8 PM.
• Joint PhD defence
• Supervisors: Prof. N. Devoogdt, prof M. Meeus and prof. A. De Groef

Abstract

The Belgian Cancer Registry reported 10,905 new female breast cancer patients in 2018. Although successful screening, early intervention and enhanced treatment options have improved breast cancer survival, 90% of survivors suffer lifelong sequelae, which substantially impair daily life functioning and quality of life. One of the most frequently reported side effects of breast cancer treatments is pain, possibly affecting all aspects of functioning, including physical activity, upper limb use and return to work. As a result, adequate pain management during the early stages of breast cancer treatment is essential for resolving and preventing these issues, both in the short and long term.

Over the last few decades, there has been a greater understanding of the important role of educational interventions in the management of pain. However, they mainly focus on tissue injury as the source of pain and are often restricted to biomedical pain management instructions. Only recently, increased knowledge on pain mechanisms has resulted in a more modern educational approach, also known as pain science education (PSE). During the sessions, the patient is explained that pain is not always a true representation of the actual state of the tissues, but that it is the brain’s interpretation of the threat of the injury, which is influenced by a variety of psychosocial factors. By zooming out of the purely biomedical vision on pain, PSE aims for a reconceptualization from a biomedical or structural model to an actual biopsychosocial one. Patients who understand that tissue damage is not the only cause of pain, but that stress, sleep, social interactions and physical activity, among other things, can all influence the pain experience, may be more likely to engage in activities they previously avoided due to pain. This, in turn, may lead to improved functioning.

The existing evidence for the potential benefits of PSE in non-cancer pain populations, along with the lack in methodologically strong studies in breast cancer patients, led us to the main research objective of this PhD research project, which was to investigate the effectiveness of PSE in improving functioning after breast cancer surgery.

In conclusion, this work provides deeper insights into the follow-up of pain-related disability after breast cancer surgery, as well as the clinical application of PSE in this population and recommendations for further research. At first glance, our findings suggest that PSE does not ensure more favorable outcomes compared to biomedical pain education. However, several concerns were raised about the PSE intervention’s cookie-cutter approach, leading to the conclusion that the question should not be whether educational interventions are necessary, but rather how the delivery method, timing and other factors could be refined to achieve a change in behavior and, as a result, improved functioning. The complexity of educational interventions combined with a health care system that is entirely biomedical in nature will require years of efforts to optimize these interventions through a variety of mechanisms.

Rawlance Ndejjo

• 22 September 2021
• Time: 3:30 PM - 5:30 PM.
• Public defence
• Supervisors: Prof. H. Bastiaens, dr. G. Musinguzi and Prof. R. Wanyenze

Abstract

Cardiovascular disease (CVD), the number one cause of death globally, disproportionately affects low- and middle- income countries (LMICs) creating a new burden for their unprepared health systems amidst resource constraints. Community-wide interventions targeting CVD risk factors can support CVD prevention and control efforts in LMICs. However, there is need for more evidence on the effectiveness of community-based interventions for CVD prevention and an exploration of their implementation processes in real-world settings.

The objectives of this research were to synthesise evidence and examine the implementation process of a community CVD prevention programme in Mukono and Buikwe districts in Uganda to inform scale-up in a low-income context. We employed a mixed methods study design to answer the research questions. Besides a systematic review that was conducted to synthesise evidence on effectiveness of community-based interventions for CVD prevention among adults in LMICs, the remaining objectives were answered using primary data collected in Mukono and Buikwe districts in Uganda using quantitative and qualitative approaches.

Results from the systematic review revealed that community-based interventions successfully improved population knowledge on CVD and risk factors and influenced physical activity and dietary practices for CVD prevention. However, evidence was inconsistent for smoking cessation and reduced alcohol consumption. The most effective interventions involved health education, community mobilisation and lifestyle counselling (Paper I). To inform the community CVD prevention programme, we collected baseline data from 4372 respondents and found that only 776 (17.7%) were knowledgeable on CVD prevention with several associated factors (Paper II). Mapping of the prevalence of selected CVD risk factors using the baseline data indicated substantial gender and small area geographic heterogeneity which was masked on aggregate analysis (Paper III). Evidence on effective interventions together with gaps identified in knowledge and CVD risk practices informed the design of our intervention which was acceptable to both CHWs and community members (Paper IV). The barriers of implementation included complexity, low CVD knowledge and CHW competing demands. The facilitators were availability of inputs and protective equipment, being trained, frequent support supervision (Paper V). Following implementation, we found variations in uptake of healthy lifestyle practices for CVD prevention with most changes reported for dietary behaviour and physical activity than alcohol consumption, smoking behaviours, and stress reduction like our review findings (Paper VI).

Evidence-based, acceptable, and well-designed community-based interventions led by community health workers can support uptake of healthy lifestyles that are key for CVD prevention. These interventions hold promise for LMICs to deal with CVD.

Andrea Torneri

• 21 September 2021
• Time: 3:30 PM - 5:30 PM.
• Online defence
• Supervisor: Prof. N. Hens

Tinne Van Aggelpoel

• 9 September 2021
• Time: 3 PM - 5 PM.
• Online defence
• Supervisors: Prof. A. Vermandel and Prof. S. De Wachter

Abstract

Elien Augustus

• 31 August 2021
• Time: 5:15 PM - 7:15 PM.
• Public defence
• Supervisors: Prof. P. Pauwels, prof. M. Peeters and prof. G. Roeyen

Abstract

In order to provide cancer patients with a personalized treatment, molecular understanding of the tumor is indispensable. Today, tissue biopsies are often used to characterize the tumor. However, tissue biopsies face some limitations. Circulating cell-free DNA (cfDNA) in liquid biopsies might overcome these issues. Analyzing cfDNA is a cost-effective, minimal invasive technique that enables repetitive sampling and gives real-time information on the tumor characteristics The first objective of this thesis was to establish some standardized guidelines on the use of urine samples for cfDNA analysis in the management of cancer patients. We collected urine samples from 39 healthy volunteers and 14 cancer patients. Based on our results, we advise to: (i) isolate cfDNA from the whole urine sample; (ii) store fresh urine samples at 4°C and centrifuge them with a two-step centrifugation protocol as soon as possible after sample collection; (iii) supplement urine samples with a preservative in case the samples cannot be processed immediately after collection, store these samples at room temperature and centrifuge them with a short one-step centrifugation protocol at high speed. The second objective was to investigate the prognostic value of cfDNA in 10 non-small cell lung cancer (NSCLC) patients receiving immunotherapy. We found that NSCLC patients without detectable levels mutated cfDNA in their liquid biopsy samples, had a better clinical outcome compared to patients with detectable levels. We also compared the performance of next-generation sequencing (NGS) for genomic alterations in tissue samples with liquid biopsy samples. We were able to detect gene amplifications in the blood-derived cfDNA of the included NSCLC patients. Furthermore, we identified a resistance mechanism against alectinib in a blood sample of one NSCLC patient. The third objective was to study the role of liquid biopsy for the follow-up of PDAC patients. We studied the cfDNA derived from matched plasma and urine samples of 47 pancreatic ductal adenocarcinoma (PDAC) patients who underwent surgery and 26 metastatic PDAC patients. According to our results, plasma might be a more suitable body fluid than urine when evaluating the levels cfDNA to monitor PDAC patients. Secondly, our data show that the sensitivity of a liquid biopsy test can be increased by combining multiple tumor markers. We also found that cfDNA analysis enables the detection of disease progression in patients whose total tumor volume (primary tumor and metastases) increases. However, the detection of small primary tumors or new metastases can be challenging when using liquid biopsy.

Jan Van Looveren

• 9 July 2021
• Time: 5 PM - 7 PM.
• PhD defence
• Supervisors: Prof. C. Koppen and Em. Prof. MJ. Tassignon

Abstract

Despite tremendous efforts in recent years to increase the understanding of pediatric cataract formation and to refine its surgical approach, pediatric cataract is still the number one cause of childhood blindness and is in many cases still classified to be of unknown origin. When operating pediatric cataracts using the bag-in-the-lens implantation technique the presence of an abnormal Berger’s space was observed with adhesions between the posterior lens capsule and the anterior hyaloid membrane in many of these idiopathic cases. The anomaly of Berger’s space in these pediatric cataracts was defined as anterior vitreolenticular interface dysgenesis (AVLID). A strong correlation was found between AVLID and unilateral cataract and when confronted with a posterior capsular plaque after lens removal. Based on the proteins found in these plaques they are speculated to be the result of an epithelial-mesenchymal transformation. Congenital cataracts associated with AVLID are more challenging to cataract surgeons.  Intraoperative optical coherence tomography of the lens proved to be a supplementary and objective tool for early AVLID detection and to anticipate surgical difficulties. Increasing knowledge on AVLID will help to find the best surgical approach in these peculiar pediatric cataracts and maybe one day prevent them to occur.

Evi Matthys

• 8 July 2021
• Time: 5 PM - 7 PM.
• Online defence
• Supervisors: Prof. P. Van Bogaert and prof. R. Remmen

Abstract

De integratie van praktijkverpleegkundigen in de Vlaamse huisartsenpraktijken kan bijdragen aan het tegemoetkomen van bestaande zorgnoden. De multiprofessionele samenwerking tussen huisartsen en praktijkverpleegkundigen wordt geassocieerd met tal van verbeterde patiëntenuitkomsten, in het bijzonder bij patiënten gediagnosticeerd met een chronische aandoening. Daarnaast wordt de samenwerking zowel door patiënten, als door huisartsen en praktijkverpleegkundigen als positief ervaren.

De voornaamste barrières ten aanzien van de integratie van een praktijkverpleegkundige in de huisartsenpraktijk zijn het huidige betalingssysteem, het onduidelijke profiel en het onduidelijk ethisch kader van praktijkverpleegkundigen. Wanneer huisartsen een samenwerking initiëren, wordt deze keuze voornamelijk gemotiveerd door de ervaren behoefte om meer kwalitatieve zorg te kunnen verlenen. Momenteel zijn het de early adopters die een geïntegreerde samenwerking met een praktijkverpleegkundige realiseren.

Praktijkverpleegkundigen nemen een breed takenpakket op in de huisartsenpraktijken, waarbij de taken zich situeren binnen zeven domeinen. Verpleegtechnische zorgen, administratieve taken, preventietaken, chronische zorgen, evidence-based praktijkvoering, coördinerende taken en welzijnszorg. Het belang van een postgraduaatopleiding voor praktijkverpleegkundigen en van zorgprotocollen in de huisartsenpraktijk, om een geïntegreerde samenwerking te kunnen realiseren, wordt door zowel praktijkverpleegkundigen als huisartsen erkend.

Aanbevelingen ten aanzien van huisartsenpraktijken, huisartsen en praktijkverpleegkundigen, maar ook ten aanzien van onderwijs en beleidsmakers, worden gedaan. Dit om de verdere integratie van praktijkverpleegkundigen in de Vlaamse huisartsenpraktijken mogelijk te maken, en bijgevolg om tegemoet te kunnen komen aan de veranderende zorgnoden van de eerstelijnspopulatie.

Helena Berlamont

• 6 July 2021
• Time: 4 PM - 6 PM.
• Online joint PhD defence
• Supervisors: Prof. F. Haesebrouck (UGent), Prof. R. Vandenbroucke (UGent) and Prof. A. Smet (UAntwerpen)

Abstract

Non-Helicobacter pylori Helicobacter (NHPH) species naturally colonize the stomach of animals, but some of them can also infect the human stomach. The most prevalent NHPH species in the human stomach is Helicobacter suis (H. suis), which naturally colonizes the stomach of pigs and non-human primates. Transmission of H. suis from pigs to humans might occur through direct or indirect contact or through the food chain. NHPH infections have been associated with gastritis, gastric and duodenal ulcers, and MALT lymphoma in humans.

We first investigated the potential virulence factors of H. suis and H. heilmannii (another zoonotically important cat-/dog-associated NHPH) playing a role in the adherence to the human gastric mucosa. Using RNA sequencing, we identified bacterial genes that are differentially expressed in a H. suis (HS1) and H. heilmannii (ASB1) strain when adhered to the human gastric epithelial cell line MKN7 in comparison to non-adhered H. suis and H. heilmannii bacteria. Our study suggests that the porcine H. suis strain HS1 and the feline H. heilmannii strain ASB1 use distinct pathways when adhering to human gastric epithelial cells.

Mounting evidence suggests a potential role of H. suis in Parkinson’s disease (PD). To investigate this further, a 6-hydroxydopamine (6-OHDA) PD mouse model was used. Two animal experiments with H. suis-infected mice (acute and chronic H. suis infection) were performed whereby 6-OHDA was stereotactically injected in the left brain striatum 1 week prior to euthanasia. Remarkably, a lower % loss of dopaminergic neurons was seen in the H. suis–6-OHDA groups compared to the control–6-OHDA groups. This potential protective effect of H. suis against 6-OHDA-induced toxicity needs further elucidation.

Diagnosis of NHPH infections is difficult and most techniques used for H. pylori diagnosis lack sensitivity and/or are not able to discriminate between different gastric Helicobacter species. Therefore, we investigated whether MALDI-TOF MS might constitute a potential tool for future diagnosis of NHPH infections. While our study showed that MALDI-TOF MS allows rapid differentiation between gastric Helicobacter species, further research to enable its use in clinical practice is needed.

To improve treatment strategies of H. suis infections in humans, we determined the in vitro susceptibility of 35 H. suis isolates (i.e. 20 porcine isolates and 15 non-human primate isolates) to 15 antibiotics. Our study indicates that acquired resistance occasionally occurs in H. suis isolates and that porcine isolates may be intrinsically less susceptible to aminopenicillins and tetracyclines than primate isolates.

Tomislav Kostyanev 

• 1 July 2021
• Time: 4 PM - 6 PM.
• Online defence
• Supervisor: Prof. H. Goossens

Auwal Abdullahi

• 29 June 2021
• Time: 5 PM - 7 PM.
• Online defence
• Supervisors: Prof. W. Saeys and prof. S. Truijen

Barbara Willekens

• 25 June 2021
• Time: 5 PM - 7 PM.
• Online defence
• Supervisors: Prof. P. Cras and prof. N. Cools

Abstract

Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system (CNS) in which an autoimmune T cell response towards myelin peptides plays an important role. Despite the availability of more than ten approved drugs for the treatment of MS, there still is a significant unmet need for novel therapeutic approaches. The holy grail is to find a treatment that leads to restoration of immune tolerance towards myelin peptides while leaving other immune effector functions intact. Dendritic cells (DC) are potent antigen-presenting cells and function as gatekeepers of the immune system, directing both T cell immunity and tolerance. Previously, we have demonstrated that dendritic cells of MS patients are in a hyperactivated state and show increased migratory capacity towards the CNS. Furthermore, we have developed antigen-specific tolerogenic dendritic cells, that have the capacity to downregulate autoreactive myelin-specific T cell responses in vitro and in vivo in an EAE-model. In a systematic review and meta-analysis on tolerance inducing cell-based therapies in autoimmune diseases, including MS, neuromyelitis optica, rheumatoid arthritis, Crohn’s disease, diabetes type I and organ transplantation, we demonstrated that tolerogenic dendritic cells, mesenchymal stem cells and regulatory T-cells are safe in the short term.
We aimed to demonstrate that tolerogenic cell-based therapy is safe and feasible in a first-in-man study in active MS patients. Hence, a harmonized study protocol of two dose-escalation phase I clinical trials, aiming to compare two ways of administration of tolDC (intradermal and intranodal) was designed. In this thesis, the interim results of the phase I clinical trial to assess safety and feasibility of intradermal tolDC administration in Antwerp, Belgium are discussed.  The baseline and follow-up data of the first two dose cohorts, receiving 5 and 10 million tolDC per injection, show that it is safe and feasible to administer tolDC in active MS patients. The third dose cohort, receiving 15 million tolDC per injection is ongoing.
Furthermore, we took the first steps into development of a biomarker for measuring efficacy of myelin-specific T cell responses in MS patients. A longitudinal study in which interferon-gamma EliSPOT was used to measure myelin-specific T-cell reactivity in the peripheral blood of stable MS patients demonstrates that myelin specific T cell responses show intra- and interindividual variation over time.  This PhD thesis describes the first steps in the clinical translation and development of a tolerance-inducing dendritic cell-based treatment in MS, paving the way towards a phase II clinical trial.

Jessy Elst

• 23 June 2021
• Time: 5 PM - 7 PM.
• Online PhD defence
• Supervisors: Prof. D. Ebo, prof. V. Sabato and prof. M. Hagendorens

Neil Wood

• 22 June 2021
• Time: 5 PM - 7 PM.
• Online joint PhD defence with Sefako Makgatho Health Sciences University
• Supervisors: Prof. R. Lebelo, Prof. S. Boy, Prof. JP. Bogers and Prof. O. Vanderveken 

Sebastien Janssens de Varebeke

• 18 June 2021
• Time: 5 PM - 7 PM.
• Online defence
• Supervisors: Prof. V. Van Rompaey and prof. G. Van Camp

Abstract

DFNA9 is an autosomal dominant hereditary hearing disorder associated with vestibular deterioration with a late onset of symptoms. Many variants in COCH have been identified, however, the c.151C>T, p.Pro51Ser is highly prevalent in the Low Countries. The clinical characteristics of this condition were based on genetic linkage studies of some 15 years ago. However, nowadays, new clinical vestibular tools permit more detailed observation of the progression of the vestibular deterioration at different compartments and at different frequency range of the vestibular organ. Since the last several years, tremendous efforts are being displayed to develop new therapeutic options, such as vestibular implants and genetic therapy, for which a better knowledge of the natural course of DFNA9 has become essential to define the most optimal therapeutic window. A prospective multi-centric cross-sectional study, conducted in Antwerp and Hasselt, including 111 Belgian & Dutch p.Pro51Ser variant carriers, showed the following results: 1) the hearing thresholds at 8 kHz were already beyond age-referenced limits in the youngest age group (18-25 years), 2) this was followed by the decline of caloric response (35 years on average) and C-VEMPs (31 years). 3) The hearing frequencies higher than 2 kHz all started to deteriorate at about 34-38 years of age, whereas the lower frequencies started their decline ten years later. 4) The vestibulo-ocular reflexgains, which are obtained with high angular acceleration video head impulse test (vHIT), were the last to deteriorate (end of 4th & early 5th decade). Imaging of DFNA9 patients showed typical features like focal sclerosis or T2-weighted signal loss in semicircular canals (SCC) of p.Pro51Ser carriers that had reached advanced stages of oto-vestibular deterioration. These lesions seemed to correlate with lower caloric and vHIT function. These findings suggest an (auto)immune reaction as a result of accumulation of misfolded mutant cochlin in the inner ear and ampullae of the SCC, with fibrosis and late-onset calcification. Until 2018, all known COCH variants had autosomal dominant trait, however, we identified a new COCH variant with an autosomal recessive trait, causing congenital hearing loss (DFNB110). Since adult heterozygous carriers in that family all showed normal hearing and balance function, this suggests haploinsufficiency is not the cause of hearing disorder, but rather the dominant negative trait of these new variants. These new insights are useful in future research for new treatment options in DFNA9 patients.

Maxime De Laere

• 11 June 2021
• Time: 4 PM - 6 PM.
• Online defence
• Supervisors: Prof. Z. Berneman and prof. N. Cools

Abstract

Multiple sclerosis (MS) is an autoimmune disease of the central nervous system (CNS). It has been shown that the accumulation of dendritic cells (DC) in the CNS is a rate-limiting factor for neuroinflammation in both early stages as well as during established disease. Indeed, the presence and number of DC in the inflamed CNS correlates with disease severity. The presence of tolerogenic (tol)DC in the CNS, on the other hand, has been shown to downmodulate ongoing inflammation in experimental animal models.

Different routes of entry exist for DC to reach the CNS, but most of the DC-inherent molecular pathways and mechanisms underlying their migration to the inflamed CNS remain elusive. In this thesis, we aimed to elucidate the molecular mechanisms underlying DC trafficking across the blood-brain barrier (BBB) in the context of MS pathogenesis, in view of identifying targets and approaches to modulate DC migration, either by interfering with inflammatory DC trafficking or by enhancing tolDC homing to the inflamed CNS.

Using an in vitro BBB model, we studied gene expression patterns of migrating and non-migrating DC from relapsing-remitting MS patients, progressive MS patients, and healthy controls. We identified a transcriptional program driven by the transcription factor EGR-1, which could be the driving force behind the elevated chemokine-induced migration observed in MS-derived DC. Moreover, a series of proinflammatory genes with elevated expression in MS-derived migrating DC were identified, providing increased insight into how these cells contribute to local inflammatory processes within the CNS. Compared to DC of healthy controls, migrating DC of untreated MS patients are characterized by the expression of genes driving inflammatory responses, including several genes which have been shown to be associated with a Type 1 and Type 17 T helper cell bias when activated in DC. Remarkably, expression of specific anti-inflammatory markers was also found to be upregulated in MS-derived DC, pointing towards the existence of a delicate immunomodulatory balance in DC functioning and/or between DC subsets in MS.

Next, we investigated the CCR5-driven inflammatory migratory capacity of in vitro generated Vitamin D3-stimulated tolDC, which proved to be minimal. This limitation could be overcome by inducing de novo CCR5 expression by means of mRNA electroporation. Importantly, the tolerogenic phenotype and function of tolDC was not impacted by mRNA electroporation. These data provide proof-of-concept for the possibility of generating so-called ‘designer’ tolDC, i.e. tolDC in which specific properties have been introduced artificially to increase their clinical potential.

Ben Gys

• 2 June 2021
• Time: 5.15 PM - 7.15 PM.
• Online defence
• Supervisors: Prof. G. Hubens and prof. N. Komen

Abstract

Bariatrische chirurgie evolueert snel en is sterk aanwezig in de huidige chirurgische praktijk. Niet alleen door de complexe procedures, maar ook door de noodzaak van zeer intensieve preoperatieve patiëntenscreening en postoperatieve follow-up, is het één van de meest uitdagende niches binnen de abdominale chirurgie geworden.

De nood aan revisionele chirurgie is altijd aanwezig geweest vanwege complicaties op korte of lange termijn. Het omgaan met deze complicaties is een grote uitdaging en moet in een multidisciplinaire setting worden georganiseerd. Historische kennis van bariatrische technieken is van het allergrootste belang, evenals een patiëntgerichte aanpak bij de keuze voor de juiste revisionele procedure. Keuzes moeten met de patiënt worden besproken in meerdere consultaties om aan de verwachtingen tegemoet te komen.

Toekomstige technieken in bariatrische heelkunde zijn ontwikkeld in de laparoscopie (zoals hechtdraden met weerhaakjes) en endoscopie (zoals NOTES). Op dit moment worden veel open en laparoscopische technieken uit het verleden endoscopisch nagebootst (LAGB en TERIS, VBG en TOGa®, LGCP en ESG / POSE™, RYGB en endoluminele bypass / mucosale resurfacing, BDP-DS / JIB en IMAS / IAS). Sommigen van deze technieken zijn echter om verschillende redenen reeds lang geleden verlaten.

De beste manier om toekomstige technieken in te schatten, is door terug te kijken naar het verleden en kennis op te doen over de motieven waarom soortgelijke interventies zijn mislukt.

Toekomstig onderzoek naar de niet-conservatieve behandeling van morbide obesitas, inclusief de noodzaak voor revisionele chirurgie, moet worden uitgevoerd door middel van studies die zijn gebaseerd op de piramide van wetenschappelijk bewijs.

Tijdens de voorbereiding van dit proefschrift werd een overvloed aan laagkwalitatieve publicaties waargenomen. Er is dringend behoefte aan RCTs en meta-analyses om de indicatie en plaats van toekomstige (en revisionele) bariatrische technieken in de huidige praktijk te bepalen. De behoefte aan onderzoek is van het allergrootste belang omdat dit zal leiden tot de ontwikkeling van officiële en reproduceerbare richtlijnen die op het moment van schrijven ontbreken.

Okoboi Stephen

• 26 May 2021
• Time: 4 PM - 6 PM.
• Online defence
• Supervisors: Prof. JP. Van geertruyden and dr. B. Castelnuovo

Abstract

HIV self-testing (HIVST), a process by which a person performs an HIV test on himself or herself to know their HIV sero-status, is an accessible evidence-based self-controlled tool that can empower MSM to overcome healthcare stigma and discrimination, and increase access to HIV testing.  Peer delivered HIV self-testing through MSM networks could be synergistic to existing HIV prevention programs in a high-burden population unconnected to conventional health systems. A peer is defined as a non-clinically trained person with similar background characteristics to the beneficiary population. The World Health Organization (WHO) recommends peer approaches to improve the uptake of HIV testing - the entry point to HIV care and timely linkage to care after testing. Combining HIVST with peer network delivery offers a unique opportunity to reach MSM with user-friendly technology in their community. However, these strategies have not been combined to extend the reach of HIV testing services into African MSM social and sexual networks, and no study has estimated the cost and cost-effectiveness of peer delivery of HIVST kits in Sub-Saharan Africa.

In this thesis, we examine:

·        acceptability of HIVST among MSM and health care workers,

·        preliminary effectiveness of the MSM peer HIVST kit distribution in identifying undiagnosed HIV infection compared with standard of care HIV testing,

·        the cost and cost-effectiveness of the peer HIVST kit distribution compared to standard of care HIV testing among MSM.

We used:

·        a qualitative design to assess acceptability of HIVST,

·        a non-randomized study to evaluate the preliminary effectiveness of peer distribution regarding the HIV self-testing (HIVST) kits compared with standard of care in identifying undiagnosed HIV infection, and

·        the provider perspective to estimate cost and cost-effectiveness of the peer distribution of the HIV self-testing (HIVST) kit compared with the standard of care in identifying undiagnosed HIV infection at The AIDS Support Organization (TASO) centers in Entebbe and Masaka.

Key results

We observed that peer-delivered HIV self-testing in MSM networks was highly acceptable. MSM participants further described HIV self-testing as a mechanism that would facilitate the uptake of HIV testing in a rapid, efficient, confidential, non-painful, and non-stigmatizing manner. MSM participants were also willing to distribute HIV self-test kits to their sexual and social networks. Health care workers were supportive of HIV self-test kit distribution through MSM peers.

Out of 297 participants included in the non-randomized study, 150 received HIVST (intervention) and 143 received standard of care HIV testing within three months. We observed that 95% of the MSM completed HIVST, of which 32% had never tested for HIV, while 100% completed SOC testing. A total of 12 participants were diagnosed with HIV: eight in the intervention arm, and four in the SOC group [5.6% versus 2.7%, respectively; P=0.02]. All participants newly diagnosed using HIVST received confirmatory HIV testing and were linked to care by the peers, who provided pre and post- test HIV counselling.

The provider cost for the MSM peer distribution strategy (intervention arm) was $2,276 compared with $1,827 for SOC in the three-month study period. Overall, the MSM peer strategy resulted in higher HIV positivity yield (4.9% vs. 1.4%) and averted more HIV infections per year (0.364 vs. 0.104) compared with SOC. The cost per person tested was higher for the MSM peer strategy compared to SOC ($15.90 vs $12.40). Importantly, the cost per new HIV diagnosis ($324 vs. $914) and cost per transmission averted ($6,253 vs. $17,567) were lower for the peer distribution approach relative to SOC. The incremental cost per HIV transmission averted by the self-testing program was $1,727. The incremental cost to providers per additional HIV-positive person identified by the intervention was $112.3.

Conclusions

The distribution of HIVST kits by MSM peers is an acceptable strategy that can promote access and uptake to HIV testing. HIVST was perceived by participants as beneficial: it would address many barriers that affect their acceptance of HIV testing such as healthcare stigma. However, a combined approach that includes peer support for confirmatory HIV testing and immediate, linkage to HIV treatment, and prevention services is needed for effective epidemic control. Peer distribution of HIVST through MSM networks is feasible, effective, diagnoses more new HIV infections than SOC approach.

Using a costeffectiveness threshold set at US $2,129.10, peer distribution of HIVST kits was cost-effective, averted more HIV transmissions and identified more undiagnosed HIV infections than SOC hotspot testing. Peer HIVST distribution programs should be scaled up among hard to reach populations, with the aim of diagnosing 95% of all persons with HIV by 2030 (UNAIDS first 95 -95-95 target).

Eytan Breman

• 12 May 2021
• Time: 5 PM - 7 PM.
• Online defence
• Supervisors: Prof. D. Abramowicz and em.prof. F. Claas

Abstract

In this thesis, we have assessed methods to measure indirect alloreactive T-cells and investigated the optimal routes of alloantigen processing and presentation by different APCs. We discovered that using cellular material as alloantigens leads largely to recognition through the semi-direct pathway of allorecognition and not indirect allorecognition when using monocytes and dendritic cells (DCs) as APCs. Indirect allorecognition was achieved in all APCs assessed when proteins or long synthetic peptides were used. Interestingly, even plasmacytoid DCs could induce indirect allorecognition upon specific secondary signals of stimulation. Utilizing the optimized conditions, we measured the contribution of indirect allorecogtive T-cells in a patient cohort of renal transplant recipients. The results suggested the activation of T-cells under certain patients, but as no alloantibodies could be detected in the patients they could not be validated. Therefore, a second retrospective study was conducted in a cohort of women that have delivered children and developed alloantibodies against the children. Unfortunately the material was of tool quality and quantity to allow for a proper analysis of indirect alloreactive T-cells, and was inconclusive.
In conclusion, methods have been developed to allow for the assessment of indirect alloreactive T-cells in a clinical setting although validation is still required, and additional technological features can be included to allow for a more through characterization of indirect alloreactive T-cells.

Elke Kreps

• 12 May 2021
• Time: 5 PM
• Online defence
• Supervisors: Prof. C. Koppen, Prof I. Claerhout (UGent) and prof. B. Leroy (UGent)

Abstract

Modern day corneal imaging devices allow very detailed analysis of the cornea. In our first paper, we investigated the inherent variability of repeated measurements in eyes with varying degrees of keratoconus. This variability is clinically relevant and needs to be taken into account when assessing eyes with keratoconus for corneal crosslinking. This technique allows to strengthen the cornea, and thus stop keratoconus progression without markedly improving vision. In our second paper, we discussed the current diagnostic and referral patterns of keratoconus, illustrating the difficulty of early diagnosis of keratoconus at the primary eye care level. In our third paper, we presented the results of a school-based screening study, which allowed detection of both keratoconus and inadequately corrected refractive errors.  Further research is needed regarding cost-effectiveness of this screening strategy.

Several types of specialty contact lenses are available nowadays to improve vision in keratoconus. We investigated the role of scleral lenses, large-diameter rigid lenses that rest on the sclera (white tissue surrounding the clear cornea). Fitting of these lenses was found to significantly improve both visual acuity and vision-related quality of life in patients with keratoconus. In two subgroups that typically require corneal transplant surgery, very advanced keratoconus and post-hydrops keratoconus, scleral lenses allowed for satisfactory vision in the majority of patients and considerably reduced the need for corneal transplant surgery. The role of hybrid lenses, consisting of a central rigid lens and a soft skirt, in the correction of keratoconus was studied in the seventh paper. In clinical practice, the outcome of these lenses still remains suboptimal.

The advent of corneal crosslinking and innovations in contact lens care have both shifted the desired timing of diagnosis and treatment to earlier in the disease and have reduced the need for corneal graft surgery.

George Elias

• 26 April 2021
• Time: 1 PM - 3 PM.
• Online defence
• Supervisors: Prof. V. Van Tendeloo and prof. B. Ogunjimi

Anne Sieben

• 22 April 2021
• Time: 6 PM
• Online joint PhD defence
• Supervisors: Prof. P. Boon (UGent), prof. P. De Deyn (UA) and prof. P. Santens (UGhent)

​Abstract

This thesis covers the neuropathological evaluation of a young onset FTLD cohort, with specific interest in vascular and other age-related alterations. In a review paper, the different FTLD syndromes and their genetics were described.

A first study included the creation of a cohort of young onset FTLD cases from the brain bank of the Institute Born-Bunge. The study resulted in 106 well characterized cases of which FTLD with TDP-43 pathology was most prevalent. A semi-quantitative rating of cerebrovascular pathology was also included.

In a next study the cerebrovascular pathology was assessed in a 9 members of the Belgian progranulin gene (GRN) founder family. The neuropathological analysis in all cases showed FTLD-TDP type A, combined with mild AD, age-related tauopathy or Lewy body disease. Additionally, cerebrovascular disease (CVD) was found and scored in every case.

Next to TDP-43 proteinopathies, our FTLD cohort also consisted of cases with tauopathies. As progressive supranuclear paralysis (PSP) is the most common tauopathy, 7 PSP cases and 7 age matched control cases were neuropathologically examined to assess other comorbidities, including cerebrovascular pathology. A tendency of a higher CVD load was found in the PSP cases compared to the control cases.

Hippocampal sclerosis (HS) is a common finding in elderly patients, often associated with TDP-43, but also with CVD. In a next study, we confirmed the strong relation between HS and hippocampal TDP-43 pathology, and showed an additional  association between HS and vascular changes in the deep white matter and basal ganglia. We hypothesize that both conditions act as a double hit on vulnerable hippocampal neurons and suggest that both conditions affect each other, driving neurodegeneration and the degradation of the blood-brain barrier, leading to sclerosis and neuronal loss.

We conclude that FTLD is clinically, neuropathologically and genetically heterogeneous with plenty of overlap between the neurodegenerative mechanisms and the clinical expression thereof. This thesis demonstrates that proteinopathies are not isolated events in the aging brain. Other factors such as cerebrovascular pathology and with that the involvement of the blood-brain barrier should also be considered. We propose a multi-cellular disease concept in FTLD.

Timon Vandamme

• 20 April 2021
• Time: 1 PM - 2 PM.
• Online joint PhD defence
• Supervisors: Prof. L. Hofland (Erasmus University Rotterdam), Prof. M. Peeters, Prof. P. Pauwels and prof. K. Op de Beeck

Abstract

Lore Wyers

• 19 April 2021
• Time: 5 PM - 7 PM.
• Online joint PhD defence
• Supervisors: Prof. A. Hallemans, Prof. P. Van de Walle and prof. K. Desloovere

Abstract

Dravet Syndrome (DS) is a developmental and epileptic encephalopathy, characterised by severe epilepsy and cognitive and motor impairments. Patients with Dravet syndrome are often confronted with walking problems. As a comorbidity in the broad clinical picture of this syndrome, walking problems form a disabling factor. Studying gait deviations provides insight into the pathological processes that underlie walking problems. Research on gait in patients with DS is, however, still limited. This makes it difficult to formulate clinical advice for the evaluation and treatment of walking problems.

This PhD project aimed to characterise the main gait deviations in patients with DS. First, the state-of-the-art regarding motion analysis and gait deviations in patients with intellectual disabilities (ID) and DS is established. To this end, two review studies are conducted. Thereafter, three empirical studies document biomechanical aspects of gait in children, adolescents and young adults with DS.

Literature often described gait deviations as crouch gait in patients with DS as well as in the general population with ID. The results of the current research project confirmed that increased knee flexion increased the lower limb support moment in stance, reducing the efficiency of the gait pattern. Based on knee extensor moments and trunk lean, three kinetic strategies to maintain stance limb stability were identified. Moreover, foot function seemed impaired, as half of the participants did not consistently perform heel strikes and showed deviations in plantar pressure measures. Even though feasibility of strength measurements was low in this population, indications of dereased muscle strength were observed.

An overall inefficient gait pattern was identified, mainly characterised by increased knee flexion and diverse neurologic, motor and musculoskeletal deviations. Two main hypotheses are formulated to explain the observed gait deviations in patients with DS. First, the musculoskeletalhypothesis suggests that in DS, decreased muscle strength and lever arm dysfunction only partly explain the gait deviations. Second, the motor control hypothesis states that the contribution of impaired neuromotor control and delayed psychomotor development to gait deviations in patients with DS should not be underestimated

Philip Plaeke

• 30 March 2021
• Time: 4 PM - 6 PM.
• Online defence
• Supervisors: Prof. G. Hubens and prof. B. De Winter

Abstract

Carlo Augusto Mallio

• 11 March 2021
• Time: 2 PM - 4 PM.
• Online defence
• Supervisors: Prof. P. Parizel and prof. C. Quatrocchi

Abstract

Eline Oeyen

• 9 March 2021
• Time: 5 PM - 7 PM.
• Online defence
• Supervisors: Prof. I. Mertens, prof. S. De Wachter and prof. G. Baggerman

Abstract

Bladder cancer is the 4^th most common cancer in men and the 8^th most common in women in the Western world. Approximately 550,000 new cases occur yearly worldwide. The current gold standard methods to diagnose a bladder tumour are cystoscopy and urine cytology. However, limitations exist. Early detection is required to avoid cystectomy. Due to the high risk of relapse, intensive follow-up of bladder cancer patients is recommended. A non-invasive and inexpensive diagnostic method to detect bladder cancer in an early stage and monitor the patient to detect relapse will reduce the costs and is beneficial for the patient.

Urine biomarkers are an attractive alternative for the detection of a bladder cancer tumour. However, no urinary biomarkers are used in daily clinical practice yet due to the lack of sensitivity or specificity or negative predictive value. Recently, it was demonstrated that small extracellular vesicles (<200 nanometres), that are present in different types of liquid biopsies, are a potential source of biomarkers for cancer diagnosis. Tumour-derived vesicles have a role in cancer development and therefore a potential source of biomarkers with high sensitivity and specificity. The ultimate goal of this dissertation was to explore the cargo of urinary small extracellular vesicles to identify biomarker candidates for the initial diagnosis and recurrence diagnosis of bladder cancer patients.

Optimisation of the separation of small extracellular vesicles from urine was performed. Next, a variation analysis was performed on the isolated proteins to obtain insights into the interbiological variation and a sample size calculation was performed. Mass spectrometry was used to identify protein biomarker candidates in the urinary sEV isolates for (1) the diagnosis of an initial bladder cancer tumour and (2) the follow-up of patients to detect a bladder cancer relapse. Protein biomarkers allow the easy and fast diagnosis of biomarkers in antibody-based assays.This resulted in a list of 1,226 identified and quantified proteins and respectively 69 and 2 proteins were differentially detected based on high quality raw data. Although this study was promising, extra training cohorts are required. Ultimately, further verification and validation steps of the biomarker candidates are required to investigate the sensitivity, specificity and predictive values of the final biomarker panel and compare them with the current diagnostic standards to develop inexpensive and non-invasive tests.

Donald Vaganée

• 2 March 2021
• Time: 5 PM - 7 PM.
• Online defence
• Supervisor: Prof. S. De Wachter

Abstract

Sacral neuromodulation is a longstanding, minimally invasive treatment for patients with overactive bladder syndrome, non-obstructive urinary retention and fecal incontinence, refractory to conservative treatments. The treatment consists of placement of a tined lead with four stimulation electrodes through the third or fourth sacral foramen in order to stimulate in the vicinity of the sacral spinal nerves. Lead placement can occur under general or local anaesthesia. Correct lead position with respect to the sacral spinal nerves is determined guided by adequate pelvic floor motor and/or genital/peri-anal sensory responses after electrical stimulation. With the lead positioned, the electrodes are “programmed”, meaning that one or more electrode(s) are chosen as stimulation point(s) and an electrode as reference point. The current measurement techniques to record the motor and sensory responses during lead placement and electrode programming, are highly subject to subjectivity (visual inspection of contraction of the pelvic floor and verbal inquiry, respectively). For the motor and sensory response are considered the best indicators of optimal nerve stimulation, good tools to objectively record these responses are paramount (i.e. to improve the efficacy of sacral neuromodulation). In this thesis a multiple array electromyography probe and a pelvic chart are presented as tools to record the motor and sensory response. The validity, reliability and feasibility of these tools are assessed. Subsequently, their usefulness in clinical practice is investigated.

Tine Luyten

• 15 January 2021
• Time: 5 PM - 7 PM
• Supervisors: Em.Prof P. Van de Heyning, Em.Prof M. De Bodt and Prof A. Gilles
• Language: Dutch

Abstract

The perception of tinnitus, known as an internal sound in the absence of external auditory input, can be extremely bothersome and debilitating. Worldwide, tinnitus sounds raise awareness in 8 – 20% of the population and become chronic. For about 1 – 3 %, tinnitus is distressing and therapeutic intervention is needed.

Currently, psychotherapeutic tinnitus interventions commonly consist of psychoeducation, Tinnitus Retraining Therapy (TRT) and / or Cognitive Behavioral Therapy (CBT). The tinnitus population is frequently represented with comorbid complaints such as insomnia, anxiety and depression. For this reason, there is no treatment-fits-all and thus personalized treatment options are recommended, however, to date effective treatment options are scarce. Tinnitus is known as phantom percept and recent research on Eye Movement Desensitization Reprocessing (EMDR) and phantom pain has shown promising results.

This doctoral thesis was performed in order to gain insight in the value of EMDR as treatment for chronic subjective tinnitus, to examine whether this psychotherapeutic intervention can be applied as effective tinnitus treatment, and to explore the influence of personality traits on treatment outcome.

The first part of this dissertation investigated the existence of relevant EMDR - studies. This was the first systematic review on EMDR as treatment for tinnitus resulting in an overview of the currently existing scientifically proven studies assessed by the Platinum Standard, giving support to the effectiveness of EMDR.

Consequently, in the second part of the thesis the study protocol for a prospective, randomized controlled trial with blind evaluator was represented. A total of 166 patients with chronic, subjective, non-pulsatile tinnitus were screened and 91 patients were randomized in two treatment groups: TRT/CBT versus TRT/EMDR. Data from 89 patients were assessed at three time-points i.e. before treatment, after treatment, and at three month follow up. The focus was on analyzing the Tinnitus Functional Index (TFI) as primary outcome measurement, and the Tinnitus Questionnaire (TQ), Hyperacusis Questionnaire (HQ), Hospital Anxiety and Depression Scale (HADS), Visual Analogue Scale for tinnitus loudness (VAS_Loudness), and Global Perceived Effect (GPE) as secondary outcomes, after psychotherapeutic treatment.

Both bimodal therapies resulted in significant reduction of tinnitus distress, tinnitus related complaints, tinnitus loudness, hypersensitivity to sound, anxiety, and depressive symptoms and led to significant increase of quality of life. Assessments indicated a stable effect of these improvements after three months. The present study provides evidence for the effectiveness of both treatment protocols showing no superiority of TRT/EMDR over TRT/CBT.

In the third part, the influence of specific personality traits in therapeutic outcome was investigated. Data from the RCT were employed to identify correlations between self-report outcome measures and Big Five Inventory (BFI) personality traits. K-means cluster analysis revealed four distinct personality clusters containing a specific combination of traits.

In conclusion, these empirical findings highlight the effectiveness of both bimodal therapies showing no different efficacy and underline the significant influence of personality traits in psychotherapeutic treatments.

Silke Peeters

• 14 January 2021
• Time: 3 PM - 5 PM.
• Online defence
• Supervisors: Prof. G. Mortier and prof. W. Van Hul

Abstract

The second project of this thesis focused on children born small-for-gestational age (SGA) with persisting growth failure. In a significant proportion of SGA children, the etiology of the growth failure remains unclear after routine diagnostic work-up. In this project, we investigated whether an extensive analysis of the (epi)genome can unravel the (epi)genetic cause of growth failure in a well-defined group of 20 SGA children.

We identified (likely) pathogenic variants in two siblings and two additional probands using exome sequencing. Furthermore,

SNP array analysis in all children and their parents revealed a rare, pathogenic de novo copy number variation (CNV) in two other unrelated probands. In almost all children with a genetic diagnosis, we observed an “above average” response to growth hormone treatment. These results question the relevance of the exclusion of syndromic SGA patients from growth hormone treatment. In a subgroup of 10 children, we performed a genome-wide DNA methylation assay. This analysis revealed multi-locus imprinting disturbances in two additional children. Furthermore, in the child harboring the NSD1-containing microduplication, we identified a novel DNA methylation signature. The conclusion of this second project is that a more advanced approach with deep genotyping can unravel unexpected (epi)genomic alterations in SGA children with persistent growth failure.