Rafael Van den Bergh

Dr. Rafael Van den Bergh

Medical Department, Operational Research Unit, Medecins Sans Frontieres, Brussels, Belgium
orcid

Research Focus & Metrics

Academic Career Length

23Years (2004-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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15 April 2008 in Blood
Verified
Journal Article
Closed access
KMKiavash Movahedi
Kiavash Movahedi
MGMartin Guilliams
Martin Guilliams
Jan Van den BosscheJan Van den Bossche
Jan Van den Bossche
RBRafael Van den Bergh
Rafael Van den Bergh
CGConny Gysemans
Conny Gysemans
JGJo A. Van Ginderachter
Jo A. Van Ginderachter
The induction of CD11b+Gr-1+ myeloid-derived suppressor cells (MDSCs) is an important immune-evading mechanism used by tumors. However, the exact nature and function of MDSCs remain elusive, especially because they constitute a heterogeneous population that has not yet been clearly defined. Here, we identified 2 distinct MDSC subfractions with clear morphologic, molecular, and functional differences. These fractions consisted of either mononuclear cells (MO-MDSCs), resembling inflammatory monocytes, or low-density polymorphonuclear cells (PMN-MDSCs), akin to immature neutrophils. Interestingly, both MO-MDSCs and PMN-MDSCs suppressed antigen-specific T-cell responses, albeit using distinct effector molecules and signaling pathways. Blocking IFN-γ or disrupting STAT1 partially impaired suppression by MO-MDSCs, for which nitric oxide (NO) was one of the mediators. In contrast, while IFN-γ was strictly required for the suppressor function of PMN-MDSCs, this did not rely on STAT1 signaling or NO production. Finally, MO-MDSCs were shown to be potential precursors of highly antiproliferative NO-producing mature macrophages. However, distinct tumors differentially regulated this inherent MO-MDSC differentiation program, indicating that this phenomenon was tumor driven. Overall, our data refine tumor-induced MDSC functions by uncovering mechanistically distinct MDSC subpopulations, potentially relevant for MDSC-targeted therapies.

25 June 2020 in PLOS ONE
Verified
Journal Article
Open access
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EOEmilomo Ogbe
Emilomo Ogbe
SHStacy Harmon
Stacy Harmon
RBRafael Van den Bergh
Rafael Van den Bergh
ODOlivier Degomme
Olivier Degomme
Intimate partner violence (IPV) is a key public health issue, with a myriad of physical, sexual and emotional consequences for the survivors of violence. Social support has been found to be an important factor in mitigating and moderating the consequences of IPV and improving health outcomes. This study’s objective was to identify and assess network oriented and support mediated IPV interventions, focused on improving mental health outcomes among IPV survivors. A systematic scoping review of the literature was done adhering to PRISMA guidelines. The search covered a period of 1980 to 2017 with no language restrictions across the following databases, Medline, Embase, Web of Science, PROQUEST, and Cochrane. Studies were included if they were primary studies of IPV interventions targeted at survivors focused on improving access to social support, mental health outcomes and access to resources for survivors. 337 articles were subjected to full text screening, of which 27 articles met screening criteria. The review included both quantitative and qualitative articles. As the focus of the review was on social support, we identified interventions that were i) focused on individual IPV survivors and improving their access to resources and coping strategies, and ii) interventions focused on both individual IPV survivors as well as their communities and networks. We categorized social support interventions identified by the review as Survivor focused, advocate/case management interventions (15 studies), survivor focused, advocate/case management interventions with a psychotherapy component (3 studies), community-focused, social support interventions (6 studies), community-focused, social support interventions with a psychotherapy component (3 studies). Most of the studies, resulted in improvements in social support and/or mental health outcomes of survivors, with little evidence of their effect on IPV reduction or increase in healthcare utilization. There is good evidence of the effect of IPV interventions focused on improving access to social support through the use of advocates with strong linkages with community based structures and networks, on better mental health outcomes of survivors, there is a need for more robust/ high quality research to assess in what contexts and for whom, these interventions work better compared to other forms of IPV interventions.

9 December 2004 in Journal of Leukocyte Biology
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Journal Article
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GRGeert Raes
Geert Raes
LBLea Brys
Lea Brys
BDBhola K. Dahal
Bhola K. Dahal
JBJef Brandt
Jef Brandt
JGJohan Grooten
Johan Grooten
GGGholamreza Hassanzadeh Ghassabeh
Gholamreza Hassanzadeh Ghassabeh
Molecular markers, especially surface markers associated with type II, cytokine-dependent, alternatively activated macrophages (aaMF), remain scarce. Besides the earlier documented markers, macrophage mannose receptor and arginase 1, we demonstrated recently that murine aaMF are characterized by increased expression of found in inflammatory zone 1 (FIZZ1) and the secretory lectin Ym. We now document that expression of the two members of the mouse macrophage galactose-type C-type lectin gene family (mMGL1 and mMGL2) is induced in diverse populations of aaMF, including peritoneal macrophages elicited during infection with the protozoan Trypanosoma brucei brucei or the Helminth Taenia crassiceps and alveolar macrophages elicited in a mouse model of allergic asthma. In addition, we demonstrate that in vitro, interleukin-4 (IL-4) and IL-13 up-regulate mMGL1 and mMGL2 expression and that in vivo, induction of mMGL1 and mMGL2 is dependent on IL-4 receptor signaling. Moreover, we show that expression of MGL on human monocytes is also up-regulated by IL-4. Hence, macrophage galactose-type C-type lectins represent novel surface markers for murine and human aaMF.

9 December 2015 in PLOS ONE
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Journal Article
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UPUmberto Pellecchia
Umberto Pellecchia
RCRosa Crestani
Rosa Crestani
TDTom Decroo
Tom Decroo
RBRafael Van den Bergh
Rafael Van den Bergh
YAYasmine Al-Kourdi
Yasmine Al-Kourdi
In the Ebola Virus Disease (EVD) outbreak in Liberia, two major emergency disease-control measures were cremation of bodies and enforcement of quarantine for asymptomatic individuals suspected of being in contact with a positive case. Enforced by State-related actors, these were promoted as the only method to curtail transmissions as soon as possible. However, as with other harsh measures witnessed by Liberian citizens, in many cases those measures elicited uncontrolled negative reactions within the communities (stigma; fear) that produced, in some cases, the opposite effect of that intended. The research has been conducted in two phases, for a total of 8 weeks. Ethnography of local practices was carried out in 7 neighbourhoods in Monrovia and 5 villages in Grand Cape Mount County in Liberia. 45 Focus Group Discussions (432 participants) and 30 semi-structured interviews sustained the observing participation. Randomly selected people from different social layers were targeted. The principal investigator worked with the help of two local assistants. Perceptions and practices were both analysed. Participants stressed how cremation perpetuated the social breakdown that started with the isolation for the sickness. Socio-economical divides were created by inequitable management of the dead: those who could bribe the burial teams obtained a burial in a private cemetery or the use of Funeral Homes. Conversely, those in economic disadvantage were forced to send their dead for cremation. State-enforced quarantine, with a mandatory prohibition of movement, raised condemnation, strengthened stigmatization and created serious socio-economic distress. Food was distributed intermittently and some houses shared latrines with non-quarantined neighbours. Escapes were also recorded. Study participants narrated how they adopted local measures of containment, through local task forces and socially-rooted control of outsiders. They also stressed how information that was not spread built up rumours and suspicion. Populations experiencing an epidemic feel a high degree of social insecurity, in addition to the health hazards. Vertical and coercive measures increase mistrust and fear, producing a counter-productive effect in the containment of the epidemic. On the other hand, local communities show a will to be engaged and a high degree of flexibility in participating to the epidemic response. Efforts in the direction of awareness and community involvement could prove to be better strategy to control the epidemic and root the response on social participation.

4 December 2012 in PLOS Medicine
Verified
Journal Article
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KSKalpana Sabapathy
Kalpana Sabapathy
RBRafael Van den Bergh
Rafael Van den Bergh
SFSarah Fidler
Sarah Fidler
RHRichard Hayes
Richard Hayes
NFNathan Ford
Nathan Ford
Improving access to HIV testing is a key priority in scaling up HIV treatment and prevention services. Home-based voluntary counselling and testing (HBT) as an approach to delivering wide-scale HIV testing is explored here. We conducted a systematic review and random-effects meta-analysis of studies published between 1 January 2000 and 24 September 2012 that reported on uptake of HBT in sub-Saharan Africa, to assess the proportion of individuals accepting HBT and receiving their test result. Our initial search yielded 1,199 articles; 114 were reviewed as full-text articles, and 19 publications involving 21 studies (n = 524,867 individuals offered HBT) were included for final review and meta-analysis. The studies came from five countries: Uganda, Malawi, Kenya, South Africa, and Zambia. The proportion of people who accepted HBT (n = 474,377) ranged from 58.1% to 99.8%, with a pooled proportion of 83.3% (95% CI: 80.4%–86.1%). Heterogeneity was high (τ2 = 0.11). Sixteen studies reported on the number of people who received the result of HBT (n = 432,835). The proportion of individuals receiving their results out of all those offered testing ranged from 24.9% to 99.7%, with a pooled proportion of 76.7% (95% CI: 73.4%–80.0%) (τ2 = 0.12). HIV prevalence ranged from 2.9% to 36.5%. New diagnosis of HIV following HBT ranged from 40% to 79% of those testing positive. Forty-eight percent of the individuals offered testing were men, and they were just as likely to accept HBT as women (pooled odds ratio = 0.84; 95% CI: 0.56–1.26) (τ2 = 0.33). The proportion of individuals previously tested for HIV among those offered a test ranged from 5% to 66%. Studies in which <30% of individuals had been previously tested, local HIV prevalence was 70% uptake. It could be a valuable tool for treatment and prevention efforts. Please see later in the article for the Editors' Summary Knowledge of HIV status is crucial for both the prevention and treatment of HIV. However, according to the Joint United Nations Programme on HIV/AIDS (the UN agency responsible for HIV/AIDS), in low-and-middle-income countries only ten percent of those who need voluntary counseling and testing, because they may have been exposed to HIV infection, have access to this service. Even in health care settings in which voluntary counseling and HIV testing is routinely offered, such as to pregnant women, the number of people who use these services is low. This situation is partly because of the stigma and discrimination associated with HIV, which makes people reluctant to volunteer to come forward to be tested for HIV. To help overcome this problem, one important strategy in encouraging people to be tested for HIV is to offer them the opportunity to be counseled and tested at home—home-based voluntary counseling and testing (HBT). Using the HBT approach, people are visited in their home by health workers regardless of their perceived risk of HIV. HBT has obvious advantages and upholds the “3 Cs” principles of HIV testing: that testing is confidential, accompanied by counseling, and conducted only with informed consent. The HBT approach has received widespread international support, and the World Health Organization has recently published guidance to service providers and policy makers about the delivery of HBT. However, the acceptability of HBT, that is, whether those offered HBT actually take up the offer and are tested, remains unknown, especially in sub-Saharan Africa, the world region with the highest prevalence of HIV. So, in this study, the researchers systematically compiled all of the available studies on this topic from sub-Saharan Africa to determine the acceptability of HBT and also to and identify any factors associated with the uptake of HBT. The researchers searched several databases to identify suitable peer-reviewed studies from Africa published between January 2000 and September 2012. The researchers included studies that described any intervention to provide HIV testing at home and also reported the proportions of participants accepting HIV testing out of all individuals offered a home-based HIV test. Because different types of studies were included (such as randomized controlled trials, observational cohort studies, and cross-sectional surveys), the researchers tested the quality of included studies. Then they pooled all of the studies together to calculate the overall proportion of people who accepted HIV testing at home and the proportion who received their result. Using these methods, the researchers included 21 studies from five African countries: Kenya, Malawi, South Africa, Uganda, and Zambia, comprising a total of 524,867 people. Overall, the proportion of people who accepted HBT ranged from 58.1% to 99.7%, with a pooled proportion of 83.3% accepting HBT (474,377 people). In the eight studies that separated data by gender, men were as likely as women to accept testing (78.5% versus 81.5%). Over three-quarters of everyone who accepted HBT received their result (77% in 16 studies reporting on this), and, importantly, the proportion of people with previously undiagnosed HIV was high (40%–79% of those diagnosed HIV-positive), emphasizing the value of HBT. The researchers also found that providing incentives, local HIV prevalence being less than 10%, and targeting HBT to household members of HIV-positive individuals may be factors associated with increased uptake of HBT, but further research is needed to verify the results of this subgroup analysis. These findings suggest that voluntary counseling and testing for HIV at home is highly acceptable in five countries in sub-Saharan Africa, with the majority of those tested receiving their test result, highlighting the importance of this approach in the diagnosis of HIV. Therefore, by increasing uptake of testing, HBT may provide an effective tool for governments and health service providers to increase access to HIV treatment and prevention. However, testing is just the first step in the management of HIV, and this study does not address the follow-up of those who tested positive using the home-based approach, such as access to treatment, as well as repeated HBT for ongoing knowledge of HIV status. The option of self-testing was examined in only one of the studies included in this review, but the researchers identify that self-testing at home with the support HBT staff is an important area of future research. Overall, HBT has the potential to substantially increase awareness of HIV status in previously undiagnosed men and women in sub-Saharan Africa. Please access these websites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1001351.

19 November 2009 in Blood
Verified
Journal Article
Closed access
Jan Van den BosscheJan Van den Bossche
Jan Van den Bossche
PBPieter Bogaert
Pieter Bogaert
JHJolanda van Hengel
Jolanda van Hengel
CGChristopher J. Guérin
Christopher J. Guérin
GBGeert Berx
Geert Berx
JGJo A. Van Ginderachter
Jo A. Van Ginderachter
Alternatively activated macrophages (AAMs), triggered by interleukin-4 (IL-4) and IL-13, play a modulating role during Th2 cytokine-driven pathologies, but their molecular armament remains poorly characterized. Here, we established E-cadherin (Cdh1) as a selective marker for IL-4/IL-13–exposed mouse and human macrophages, which is STAT6-dependently induced during polarized Th2 responses associated with Taenia crassiceps helminth infections or allergic airway inflammation. The IL-4–dependent, arginase-1/ornithine decarboxylase–mediated production of polyamines is important for maximal Cdh1 induction, unveiling a novel mechanism for IL-4–dependent gene transcription. At the macrophage surface, E-cadherin forms a functional complex with the catenins that accumulates at sites of cell contact. Macrophage-specific deletion of the Cdh1 gene illustrates the implication of E-cadherin in IL-4–driven macrophage fusion and heterotypic interactions with CD103+ and KLRG1+ T cells. This study identifies the E-cadherin/catenin complex as a discriminative, partly polyamine-regulated feature of IL-4/IL-13–exposed alternatively activated macrophages that contributes to homotypic and heterotypic cellular interactions.