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8 result(s)
Journal Article > ResearchFull Text

Prediction of visceral leishmaniasis development in a highly exposed HIV cohort in Ethiopia based on Leishmania infection markers: results from the PreLeisH study

EBioMedicine. 1 December 2024; Volume 110; 105474.; DOI:10.1016/j.ebiom.2024.105474
van Griensven J, van Henten S, Kibret A, Kassa M, Beyene H,  et al.
EBioMedicine. 1 December 2024; Volume 110; 105474.; DOI:10.1016/j.ebiom.2024.105474

BACKGROUND

Targeted preventive strategies in persons living with HIV (PLWH) require markers to predict visceral leishmaniasis (VL). We conducted a longitudinal study in a HIV-cohort in VL-endemic North-West Ethiopia to 1) describe the pattern of Leishmania markers preceding VL; 2) identify Leishmania markers predictive of VL; 3) develop a clinical management algorithm according to predicted VL risk levels.


METHODS

The PreLeisH study followed 490 adult PLWH free of VL at enrolment for up to two years (2017-2021). Blood RT-PCR targeting Leishmania kDNA, Leishmania serology and Leishmania urine antigen test (KAtex) were performed every 3-6 months. We calculated the sensitivity/specificity of the Leishmania markers for predicting VL and developed an algorithm for distinct clinical management strategies, with VL risk categories defined based on VL history, CD4 count and Leishmania markers (rK39 RDT & RT-PCR).


FINDINGS

At enrolment, 485 (99%) study participants were on antiretroviral treatment; 360/490 (73.5%) were male; the median baseline CD4 count was 392 (IQR 259-586) cells/μL; 135 (27.5%) had previous VL. Incident VL was diagnosed in 34 (6.9%), with 32 (94%) displaying positive Leishmania markers before VL. In those without VL history, baseline rK39 RDT had 60% sensitivity and 84% specificity to predict VL; in patients with previous VL, RT-PCR had 71% sensitivity and 95% specificity. The algorithm defined 442 (92.3%) individuals at low VL risk (routine follow-up), 31 (6.5%) as moderate risk (secondary prophylaxis) and six (1.2%) as high risk (early treatment).


INTERPRETATION

Leishmania infection markers can predict VL risk in PLWH. Interventional studies targeting those at high risk are needed.


FUNDING

The PreLeisH study was supported by grants from the Department of Economy, Science and Innovation of the Flemish Government, Belgium (757013) and the Directorate-General for Development Cooperation and Humanitarian Aid (DGD), Belgium (BE-BCE_KBO-0410057701-prg2022-5-ET).

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Journal Article > ResearchFull Text

A preliminary indication that HLA-A*03:01 may be associated with visceral leishmaniasis development in people living with HIV in Ethiopia

PLoS Negl Trop Dis. 30 September 2024; Volume 18 (Issue 9); e0012000.; DOI:10.1371/journal.pntd.0012000
de Vrij N, Vandoren R, Ramadan K, Van Hul A, Ceulemans A,  et al.
PLoS Negl Trop Dis. 30 September 2024; Volume 18 (Issue 9); e0012000.; DOI:10.1371/journal.pntd.0012000

Human immunodeficiency virus (HIV) co-infection is a major challenge for visceral leishmaniasis (VL) control, particularly in Ethiopia where the incidence of both pathogens is high. VL-HIV often leads to high rates of antileishmanial treatment failure and recurrent VL disease relapses. Considering the high prevalence of HIV and Leishmania in the Ethiopian population, preventing the progression of asymptomatic Leishmania infection to disease would be a valuable asset to VL disease control and to the clinical management of people living with HIV (PLWH). However, such a strategy requires good understanding of risk factors for VL development. In immunocompetent individuals living in Brazil, India, or Iran, the Human Leukocyte Antigen (HLA) gene region has been associated with VL development. We used NanoTYPE, an Oxford Nanopore Technologies sequencing-based HLA genotyping method, to detect associations between HLA genotype and VL development by comparing 78 PLWH with VL history and 46 PLWH that controlled a Leishmania infection, all living in a VL endemic region of North-West Ethiopia. We identified an association between HLA-A*03:01 and increased risk of VL development (OR = 3.89). These data provide candidate HLA alleles that can be further explored for inclusion in a potential Leishmania screen-and-treat strategy in VL endemic regions.

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Journal Article > ResearchFull Text

Persistent T cell unresponsiveness associated with chronic visceral leishmaniasis in HIV-coinfected patients

Commun Biol. 3 May 2024; Volume 7 (Issue 1); 524.; DOI:10.1038/s42003-024-06225-2
de Vrij N, Pollmann J, Rezende AM, Ibarra-Meneses AV, Pham TT,  et al.
Commun Biol. 3 May 2024; Volume 7 (Issue 1); 524.; DOI:10.1038/s42003-024-06225-2
A large proportion of HIV-coinfected visceral leishmaniasis (VL-HIV) patients exhibit chronic disease with frequent VL recurrence. However, knowledge on immunological determinants underlying the disease course is scarce. We longitudinally profiled the circulatory cellular immunity of an Ethiopian HIV cohort that included VL developers. We show that chronic VL-HIV patients exhibit high and persistent levels of TIGIT and PD-1 on CD8+/CD8- T cells, in addition to a lower frequency of IFN-γ+ TIGIT- CD8+/CD8- T cells, suggestive of impaired T cell functionality. At single T cell transcriptome and clonal resolution, the patients show CD4+ T cell anergy, characterised by a lack of T cell activation and lymphoproliferative response. These findings suggest that PD-1 and TIGIT play a pivotal role in VL-HIV chronicity, and may be further explored for patient risk stratification. Our findings provide a strong rationale for adjunctive immunotherapy for the treatment of chronic VL-HIV patients to break the recurrent disease cycle.More
Journal Article > Pre-PrintFull Text

HLA-A*03:01 is associated with visceral leishmaniasis development in people living with HIV in Ethiopia

medRxiv. 18 February 2024; DOI:10.1101/2024.02.16.24302942
de Vrij N, Vandoren R, Ramadan K, Van Hul A, Kassa M,  et al.
medRxiv. 18 February 2024; DOI:10.1101/2024.02.16.24302942
Human immunodeficiency virus (HIV) co-infection is a major challenge for visceral leishmaniasis (VL) control, particularly in Ethiopia where the incidence of both pathogens is high. VL-HIV often leads to high rates of antileishmanial treatment failure and recurrent VL disease relapses. Considering the high prevalence of HIV and Leishmania in the Ethiopian population, preventing the progression of asymptomatic Leishmania infection to disease would be a valuable asset to VL disease control and to the clinical management of people living with HIV (PLWH). However, such a strategy requires good understanding of risk factors for VL development. In immunocompetent individuals living in Brazil, India, or Iran, the Human Leukocyte Antigen (HLA) gene region has been associated with VL development. We used NanoTYPE, an Oxford Nanopore Technologies sequencing-based HLA genotyping method, to detect associations between HLA genotype and VL development by comparing 78 PLWH with VL history and 46 PLWH that controlled a Leishmania infection, all living in a VL endemic region of North-West Ethiopia. We identified a strong association between HLA-A*03:01 and increased risk of VL development (OR = 3.89). These data provide candidate HLA alleles that can be further explored for inclusion in a potential Leishmania screen-and-treat strategy in VL endemic regions.More
Journal Article > CommentaryFull Text

Snakebite envenoming at MSF: A decade of clinical challenges and antivenom access issues

Toxicon: X. 21 December 2022; Volume 17; 100146.; DOI:10.1016/j.toxcx.2022.100146
Potet J, Singh SN, Ritmeijer KKD, Sisay K, Alcoba G,  et al.
Toxicon: X. 21 December 2022; Volume 17; 100146.; DOI:10.1016/j.toxcx.2022.100146
The medical humanitarian organization Médecins Sans Frontières (MSF) provides medical care in more than 70 countries and admits more than 7000 cases of snakebite in its facilities each year.

We describe our activities against snakebite in three African countries: Central African Republic, South Sudan and Ethiopia, in which different models of care have been developed. A standard protocol using two different antivenoms depending on the patient's syndrome has been introduced, and a simple blood coagulation test is performed to detect venom-induced coagulopathy. Other services, including surgery for necrotizing wounds, are offered in the facilities where MSF admits a large number of snakebite patients. All services, including provision of antivenom, are offered free-of-charge in MSF-supported facilities. Community-based activities focusing on preventive measures and prompt transport to hospital have been developed in a few MSF projects.

The provision of quality care and treatment, including effective antivenoms, without out-of-pocket payments by the patients, probably explains why MSF has admitted an increasing number of snakebite victims over the last years. This model requires significant resources and monitoring, including regular training of healthcare workers on treatment protocols and a considerable budget for antivenom procurement.
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Journal Article > ResearchFull Text

Paromomycin and miltefosine combination as an alternative to treat patients with visceral leishmaniasis in Eastern Africa: A randomized, controlled, multicountry trial

Clin Infect Dis. 27 September 2022; Online ahead of print; ciac643.; DOI:10.1093/cid/ciac643
Musa AM, Mbui J, Mohammed R, Olobo J, Ritmeijer KKD,  et al.
Clin Infect Dis. 27 September 2022; Online ahead of print; ciac643.; DOI:10.1093/cid/ciac643
BACKGROUND
This study aimed to determine whether paromomycin plus miltefosine (PM/MF) is noninferior to sodium stibogluconate plus paromomycin (SSG/PM) for treatment of primary visceral leishmaniasis in eastern Africa.

METHODS
An open-label, phase 3, randomized, controlled trial was conducted in adult and pediatric patients at 7 sites in eastern Africa. Patients were randomly assigned to either 20 mg/kg paromomycin plus allometric dose of miltefosine (14 days), or 20 mg/kg sodium stibogluconate plus 15 mg/kg paromomycin (17 days). The primary endpoint was definitive cure after 6 months.

RESULTS
Of 439 randomized patients, 424 completed the trial. Definitive cure at 6 months was 91.2% (155 of 170) and 91.8% (156 of 170) in the PM/MF and SSG/PM arms in primary efficacy modified intention-to-treat analysis (difference, 0.6%; 97.5% confidence interval [CI], -6.2 to 7.4), narrowly missing the noninferiority margin of 7%. In the per-protocol analysis, efficacy was 92% (149 of 162) and 91.7% (155 of 169) in the PM/MF and SSG/PM arms (difference, -0.3%; 97.5% CI, –7.0 to 6.5), demonstrating noninferiority. Treatments were well tolerated. Four of 18 serious adverse events were study drug–related, and 1 death was SSG-related. Allometric dosing ensured similar MF exposure in children (< 12 years) and adults.

CONCLUSIONS
PM/MF and SSG/PM efficacies were similar, and adverse drug reactions were as expected given the drugs safety profiles. With 1 less injection each day, reduced treatment duration, and no risk of SSG-associated life-threatening cardiotoxicity, PM/MF is a more patient-friendly alternative for children and adults with primary visceral leishmaniasis in eastern Africa.

CLINICAL TRIALS REGISTRATION
NCT03129646.
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Conference Material > Poster

Outcomes and effectiveness of antivenom treatments in snakebite patients in north-west Ethiopia: retrospective cohort

Steegemans IM, Sisay K, Nshimiyimana E, Gebrewold G, Piening T,  et al.
MSF Scientific Days International 2021: Research. 18 May 2021
Journal Article > ResearchFull Text

Treatment outcomes among snakebite patients in north-west Ethiopia—a retrospective analysis

PLoS Negl Trop Dis. 9 February 2022; Volume 16 (Issue 2); e0010148.; DOI:10.1371/journal.pntd.0010148
Steegemans IM, Sisay K, Nshimiyimana E, Gebrewold G, Piening T,  et al.
PLoS Negl Trop Dis. 9 February 2022; Volume 16 (Issue 2); e0010148.; DOI:10.1371/journal.pntd.0010148
BACKGROUND
Millions of people are bitten by venomous snakes annually, causing high mortality and disability, but the true burden of this neglected health issue remains unknown. Since 2015, Médecins Sans Frontières has been treating snakebite patients in a field hospital in north-west Ethiopia. Due to the poor market situation for effective and safe antivenoms for Sub-Saharan Africa, preferred antivenom was not always available, forcing changes in choice of antivenom used. This study describes treatment outcomes and the effectiveness and safety of different antivenoms used.

METHODOLOGY/PRINCIPAL FINDINGS:
This retrospective observational study included 781 snakebite patients presenting at the field hospital between 2015 and 2019. Adjusted odds ratios, 95%-CI and p-values were used to compare the treatment outcome of patients treated with Fav-Afrique (n = 149), VacSera (n = 164), and EchiTAb-PLUS-ICP (n = 156) antivenom, and to identify the risk of adverse reactions for each antivenom. Whereas only incidental snakebite cases presented before 2015, after treatment was made available, cases rapidly increased to 1,431 in 2019. Envenomation was mainly attributed to North East African saw-scaled viper (Echis pyramidum) and puff adder (Bitis arietans). Patients treated with VacSera antivenom showed lower chance of uncomplicated treatment outcome (74.4%) compared to Fav-Afrique (93.2%) and EchiTAb-PLUS-ICP (90.4%). VacSera and EchiTAb-PLUS-ICP were associated with 16- and 6-fold adjusted odds of treatment reaction compared to Fav-Afrique, respectively, and VacSera was weakly associated with higher odds of death.

CONCLUSIONS/SIGNIFICANCE
Snakebite frequency is grossly underreported unless treatment options are available. Although EchiTAb-PLUS-ICP showed favorable outcomes in this retrospective analysis, prospective randomized trials are needed to evaluate the effectiveness and safety of the most promising antivenoms for Sub-Saharan Africa. Structural investment in sustained production and supply of antivenom is urgently needed.
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