Aboubacar Alassane Oumar
Université catholique de Louvain
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Featured researches published by Aboubacar Alassane Oumar.
Retrovirology | 2010
Danielle Perez-Bercoff; Perrine Triqueneaux; Christine Lambert; Aboubacar Alassane Oumar; Anne-Marie Ternes; Sounkalo Dao; Patrick Goubau; Jean-Claude Schmit; Jean Ruelle
BackgroundHuman Immunodeficiency Virus type 2 is naturally resistant to some antiretroviral drugs, restricting therapeutic options for patients infected with HIV-2. Regimens including integrase inhibitors (INI) seem to be effective, but little data on HIV-2 integrase (IN) polymorphisms and resistance pathways are available.Materials and methodsThe integrase coding sequence from 45 HIV-2-infected, INI-naïve, patients was sequenced and aligned against the ROD (group A) or EHO (group B) reference strains and polymorphic or conserved positions were analyzed.To select for raltegravir (RAL)-resistant variants in vitro, the ROD strain was cultured under increasing sub-optimal RAL concentrations for successive rounds. The phenotype of the selected variants was assessed using an MTT assay.ResultsWe describe integrase gene polymorphisms in HIV-2 clinical isolates from 45 patients. Sixty-seven percent of the integrase residues were conserved. The HHCC Zinc coordination motif, the catalytic triad DDE motif, and AA involved in IN-DNA binding and correct positioning were highly conserved and unchanged with respect to HIV-1 whereas the connecting residues of the N-terminal domain, the dimer interface and C-terminal LEDGF binding domain were highly conserved but differed from HIV-1. The N155 H INI resistance-associated mutation (RAM) was detected in the virus population from one ARV-treated, INI-naïve patient, and the 72I and 201I polymorphisms were detected in samples from 36 and 38 patients respectively. No other known INI RAM was detected.Under RAL selective pressure in vitro, a ROD variant carrying the Q91R+I175M mutations was selected. The Q91R and I175M mutations emerged simultaneously and conferred phenotypic resistance (13-fold increase in IC50). The Q91R+I175M combination was absent from all clinical isolates. Three-dimensional modeling indicated that residue 91 lies on the enzyme surface, at the entry of a pocket containing the DDE catalytic triad and that adding a positive charge (Gln to Arg) might compromise IN-RAL affinity.ConclusionsHIV-2 polymorphisms from 45 INI-naïve patients are described. Conserved regions as well as frequencies of HIV-2 IN polymorphisms were comparable to HIV-1. Two new mutations (Q91R and I175M) that conferred high resistance to RAL were selected in vitro, which might affect therapeutic outcome.
The journal of pediatric pharmacology and therapeutics : JPPT | 2012
Aboubacar Alassane Oumar; Korotoumou Diallo; Jean Paul Dembélé; Lassana Samaké; Issa Sidibé; B. Togo; Mariam Sylla; Anatole Tounkara; Sounkalo Dao; Paul M. Tulkens
OBJECTIVES Adverse events during antiretroviral treatment are frequent and various. Their diagnosis incurs some various difficulties according to the geographic context. Our aim was to describe the frequency, nature, and preventability of adverse drug reactions (ADRs) due to antiretroviral treatment in Malian outpatient children. METHODS The study was a 6-month (June 1 to November 30, 2010) prospective, observational study of 92 children admitted to a pediatric hospital in Sikasso, Mali. The patients were treated with a generic drug and/or drug combinations. Prior to treatment initiation, demographic characteristics, clinical history, and biologic parameters, including CD4 cell counts, were collected for each patient. The World Health Organizations adverse drug reactions classification was used to characterize the side effects. Adverse effects and toxicities were graded 1, 2, and 3. Analysis of data was performed using SPSS Version 17.0 software. RESULTS Ninety-two human immunodeficiency virus-infected children met the criteria of inclusion. After 24 weeks of treatment, we observed that 14.1% of children had at least one side effect during our study. Side effects were many and varied, with the most frequent being cutaneous rash, nausea, vomiting, and diarrhea (38.5%, 23.1%, 15.4%, and 15.4%, respectively). Side effects were grade 1 in most cases. One case of grade 2 and one case of grade 3 were observed with rash. We observed one case of grade 3 side effects during our study. The treatment regimen was changed in 15.2% of cases, including one case because of side effects. CONCLUSION ADRs are not rare in Mali, particularly in children. These ADRs have an impact on quality of life for patients. We recommend a pharmacovigilance system for sustainable management of side effects in patients infected with human immunodeficiency virus in Mali.
Acta Clinica Belgica | 2010
Aboubacar Alassane Oumar; Karima Jnaoui; Benoît Kabamba-Mukadi; Jean Cyr Yombi; Bernard Vandercam; Patrick Goubau; Jean Ruelle
Abstract Background: Etravirine is a second-generation non-nucleoside reverse transcriptase inhibitor (NNRTI) with a pattern of resistance mutations quite distinct from the current NNRTIs. Methods: We collected all routine samples of HIV-1 patients followed in the AIDS reference laboratory of UCLouvain (in 2006 and 2007) carrying resistance-associated mutations to nevirapine (NVP) or efavirenz (EFV). The sensitivity to Etravirine was estimated using three different drug resistance algorithms: ANRS (July 2008), IAS (December 2008) and Stanford (November 2008). We also verified whether the mutations described as resistance mutations are not due to virus polymorphisms by the study of 58 genotypes of NNRTI-naïve patients. Results: Sixty one samples harboured resistance to NVP and EFV: 41/61 had at least one resistance mutation to Etravirine according to ANRS-IAS algorithms; 42/61 samples had at least one resistance mutation to Etravirine according to the Stanford algorithm. 48 and 53 cases were fully sensitive to Etravirine according to ANRS-IAS and Stanford algorithms, respectively. Three cases harboured more than three mutations and presented a pattern of high-degree resistance to Etravirine according to ANRS-IAS algorithm, while one case harboured more than three mutations and presented high degree resistance to Etravirine according to the Stanford algorithm. The V106I and V179D mutations were more frequent in the ARV-naïve group than in the NNRTI-experienced one. Conclusions: According to the currently available algorithms, Etravirine can still be used in the majority of patients with virus showing resistance to NVP and/or EFV, if a combination of other active drugs is included.
Journal of Pharmacology and Experimental Therapeutics | 2018
Aboubacar Alassane Oumar; Kadiatou Bagayoko-Maiga; Aliou Bahachimi; Mamoudou Maiga; Marie-Christine Cere; Zoumana Diarra; Etienne Chatelut; Mariam Sylla; Robert L. Murphy; Sounkalo Dao; Peggy Gandia
Limited data are currently available on antiretroviral pharmacokinetics in breast milk (BM) and in breastfed infants’ blood. To explore these parameters in patients in Mali, we measured plasma antiretroviral levels in human immunodeficiency virus (HIV)–infected mothers and their breastfed infants over 6 months. We specifically analyzed the concentrations of efavirenz (EFV) and lopinavir (LPV) in the plasma of mothers living with HIV and their breastfed infants. Blood samples were collected at delivery and at month 1, 3, and 6 postpartum. EFV and LPV concentrations were measured by liquid chromatography-tandem mass spectrometry. HIV-1 RNA load was measured by Abbott M2000RT RealTime System at delivery and 6 months postpartum for mothers, and at 3 and 6 months postbirth for infants. The median duration of antiretroviral therapy at study inclusion was 57 months [interquartile range (IQR), 0–168 months]. The median EFV ratios of infant plasma/maternal plasma (MP) were 0.057 at month 1, 0.072 at month 3, and 0.048 at month 6. During the study period, the median BM/MP ratio of EFV was 1.16 (IQR, 0.96–20.62), which corresponds to a relative infant dose of 2.46% of the recommended weight-adjusted pediatric EFV dose at month 6. The apparent infant clearance of EFV was 0.146 l/h per kilogram at month 6. The LPV concentrations in the plasma of all infants were undetectable. No drug-related adverse reaction or toxicity was observed in any of the infants. The two women who presented a viral load of >50 copies/ml at month 6 had undetectable plasma drug concentrations at the same period. This study showed that breastfed infants received a low level of EFV but not LPV from their treated mothers.
Journal of Pharmacovigilance | 2017
Aboubacar Alassane Oumar; Amadou Abdoulaye; Mamoudou Maiga; Younoussa Sidibe; Yacouba Cissoko; Issa Konaté; Maimouna Diarra; Fanta Sangho; Jean Paul Dembélé; Paul M. Tulkens; Sounkalo Dao
Objective: The purpose of this study was to evaluate the adverse effects of Antiretroviral Therapy (ART) in adult HIV-infected patients in decentralized setting of Sikasso, in Mali. Methods: This is a proactive study that took place from 2 January 2011 to 30 December 2012 at the Hospital of Sikasso (Department of Medicine). HIV-infected adult patients who have started ART at least 3 months before were included in this study to monitor the laboratory and clinical Adverse Drug Reactions (ADR) for at least 6 months. The WHO classification of adverse drug reactions has been used to investigate the causality of antiretrovirals. Results: Women were the most represented with 58% of the cases. The most represented age range was 26-47 years with 73.6%. Of the 178 patients enrolled, 61.2% had an ADR. ADR were neurological (40.4%), digestive (35.8%), cutaneous (18.3%) and hematological (5.5%). Stavudine was the most incriminated molecule, in 24.8% of the cases. The WHO grade 4 classification of ART toxicity was represented in 3.4% of the cases. The WHO causality score of “certain” was found in 29.8% of the cases. Conclusion: Adverse effects of Antiretrovirals are frequent and could be life-threatening in short and long terms. Regular follow-up of patients receiving these triple therapies, and the associated complications, is essential. We recommend active surveillance of antiretroviral therapy to strengthen Pharmacovigilance in Mali.
AIDS Research and Human Retroviruses | 2013
Almoustapha Issiaka Maiga; Djeneba Bocar Fofana; Aichatou Chehy Maiga; Fodie Diallo; Zaina Ait-Arkoub; Fatoumata Daou; Mamadou Cisse; Yaya Dit Sadio Sarro; Aboubacar Alassane Oumar; Aliou Sylla; Christine Katlama; Babafemi Taiwo; Robert L. Murphy; Anatole Tounkara; Marcelin Ag; Vincent Calvez
Sante Publique | 2009
Sounkalo Dao; Issa Konaté; Aboubacar Alassane Oumar; Massambou Sacko; Ibrahim Maiga; Kandioura Touré; Seydou Diarra; Flabou Bougoudogo
Sante Publique | 2009
Sounkalo Dao; Aboubacar Alassane Oumar; Benoît Traore; Moudjiron Ndoutabe; Ibrahim Maiga; Flabou Bougoudogo
Revue Malienne d’Infectiologie et de Microbiologie | 2017
Yaya Coulibaly; Fanta Sangho; Aboubacar Alassane Oumar
Revue Malienne d’Infectiologie et de Microbiologie | 2014
Seydou Diarra; Aboubacar Alassane Oumar; M Keita; Jp Dembélé; A Fofana; A Diallo; Sounkalo Dao