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Monitoring of didanosine and stavudine intracellular trisphosphorylated anabolite concentrations in HIV-infected patients.

Objective: To determine the concentrations of intracellular active anabolites of stavudine (d4T) and didanosine (DDI) and their interpatient variability in HIV-infected patients and to explore relationships between plasma and intracellular forms. Methods: This pilot study included 28 antiretroviral-naive HIV-infected patients who received d4T (40/30 mg twice daily), ddI (400/250 mg daily) and efavirenz (600 mg daily). After 6 months of therapy, 7 ml of blood was collected between 0.5 and 16.2 h and 2.5 and 28.5 h after the last dose of d4T and ddI, respectively. Plasma samples were obtained for the determination of d4T and ddI concentrations. Peripheral blood mononuclear cells were prepared for measuring intracellular d4T and ddI triphosphates (d4T-TP and ddA-TP, respectively). Results: d4T-TP and ddA-TP concentrations were above the limit of quantification in 25 of 26 compliant patients: median d4T-TP was 31 fmol/106 cells (range, 0–99) and median ddA-TP was 8 fmol/106 cells (range, 0–23). The half-life of d4T-TP was calculated as 7 h. Interpatient variability in d4T-TP and ddA-TP concentrations was 48% and 58%, respectively. A significant relationship was observed between plasma d4T and intracellular d4T-TP. No relation was found between ddI and ddA-TP. A linear relation was observed between the intracellular concentrations of d4T-TP and ddA-TP. Conclusion: This is the first time that data have been obtained on intracellular concentrations of d4T-TP and ddA-TP, their intracellular pharmacokinetics and interpatient variability. Other similar studies with more patients are needed to enhance knowledge of the intracellular pharmacology of the nucleoside reverse transcriptase inhibitors.

Tenofovir-Emtricitabine-Efavirenz in HIV-I-Infected Adults in Senegal: A 96-Week Pilot Trial in Treatment-Naive Patients

We report the results of a pilot open-label trial of a tenofovir (TDF)/emtricitabine (FTC)/efavirenz (EFV) combination conducted in Dakar, Senegal. Forty HIV-1-infected patients, naive of antiretroviral treatment and without active opportunistic disease, were included and followed through 96 weeks. At weeks 48 and 96, respectively, 82.5% and 85% of patients had HIV-1 RNA <400 copies/mL (72.5% and 77.5% with HIV-1 RNA <50 copies/mL). Between baseline and week 96, the mean (SD) CD4 count increased from 126 (102) to 338 (155) cells/mm3. The mean (SD) creatinine clearance decreased from 92 (36) to 73 (19) mL/min (P = .001). Treatment adherence was at least 94% at all scheduled visits. The efficacy and tolerability of a TDF/FTC/EFV combination were high and similar to those observed in Northern countries. This drug combination can be recommended in limited-resource countries, as did the World Health Organization (WHO) and should be made readily available as a fixed-dose combination.

PRESENCE OF HIV-1 GROUP O INFECTION IN WEST AFRICA

Two aberrant HIV-1 strains have been isolated from Cameroonian patients. The isolates had only 50% homology in the envelope region with other HIV-1 isolates and were thus classified as group O. Since then additional HIV-1 group O variants from Cameroonians living in France have been described and some of the group O sera have been shown to be unreactive in some commercial screening assays and can give indeterminate Western blot patterns. Little is known on the spread of HIV-1 group O viruses in Africa. Studying their spread is therefore very important in order to identify whether strategies for blood screening and serodiagnosis need to be modified. The authors present their serological evidence that group O infection is also present in Senegal Niger and Togo albeit to a very small degree.

Antiretroviral treatment outcome in HIV-1-infected patients routinely followed up in capital cities and remote areas of Senegal, Mali and Guinea-Conakry

Access to antiretroviral treatment (ART) becomes more and more effective in resource‐limited settings (RLS). However, this global effort would be even more profitable if the access to laboratory services especially in decentralized settings was strengthened. We report the virological outcome and HIV‐1 drug resistance in three West African countries using dried blood spots (DBS) samples.

Quantification of Viral load and resistance tests of HIV-1 to ARVs from dried blood spots samples in Guinean patients undergoing antiretroviral treatment

Problematique: Comme dans plusieurs pays du Sud, le suivi virologique des patients sous traitement antiretroviral (TARV) en Guinee est timide voire inexistant dans certaines localites. Le but de cette etude etait d’evaluer la faisabilite technique et logistique de l’utilisation des DBS dans les tests de charge virale (CV) et de genotypage. Methode: De septembre a octobre 2010, les DBS ont ete prepares a partir de prelevements sanguins de patients adultes sous TARV. Le delai d’envoi des echantillons au laboratoire de reference etait de 30 jours maximum apres le prelevement et se faisait a temperature ambiante. La CV a ete quantifiee et les echantillons de patients en echec virologique (CV ≥ 3 log10 copies/mL) ont ete genotypes selon le protocole de l’ANRS. L’algorithme de Stanford version 6.0.8 a ete utilise pour l’analyse et l’interpretation des mutations de resistance. Resultats: Parmi les 136 patients inclus, 129 et 7 etaient respectivement sous premiere et deuxieme ligne de traitement avec une mediane de suivi de 35 mois [IQR: 6-108]. L’echec virologique a ete note chez 33 patients. Parmi eux, 84.8% ( n = 28/33) ont beneficie d’ungenotypage. Le taux de resistance global etait de 14% ( n = 19/136). Le CRF02_AG etait le sous type viral le plus prevalent (82%; n = 23). Conclusion: En plus de montrer la faisabilite technique et logistique des tests de CV et de genotypage a partir des DBS, ces resultats montrent l’interet de leurs utilisations dans le suivi virologique des patients sous TARV. Cette etude a permis egalement de documenter l’echec virologique, la resistance aux ARV et la diversite genetique du VIH-1 en Guinee. Mots cles: VIH-1, Resistance aux ARV, DBS (Dried Blood Spots), Guinee Conakry, Genotypage,Charge Virale. Quantification of Viral load and resistance tests of HIV-1 to ARVs from dried blood spotssamples in Guinean patients undergoing antiretroviral treatment. Problem: As in several countries of the South, the virological monitoring of patients undergoing antiretroviral treatment (ARVT) in Guinea is low or non-existent in some locations. The aim ofthis study was to assess the technical and logistical feasibility of the use of (dried blood spots) DBSs in viral load (VL) and genotyping tests. Method: From September 2010 to October 2010, DBS were prepared from blood samples of adult patients under ARVT. The samples had to be sent to the reference laboratory within 30 days after the sample had been done at ambient temperature. The VL was quantified and the samples of patients with virological failure (CV ≥ 3 log10 copies/mL) were genotyped according to the ANRS protocol. The Stanford algorithm, version 6.0.8, was used to analyse and interpret the resistance mutations. Results: Amongst the 136 included patients, 129 and 7 were under first and second line treatment respectively, and monitored for an average of 35 months [IQR: 6-108]. Virological failure was noticed among 33 patients. Among them, 84.8% ( n = 28/33) benefited from genotyping. The global resistance rate was 14% ( n = 19/136). CRF02_AG was the most prevalent viral subtype (82%; n = 23). Conclusion: In addition to demonstrating the technical and logistic feasibility of VL and genotyping tests from DBSs, these results show the relevance of their use in the virological monitoring of patients under ARVT. Also, this study made it possible to provide informationon virological failure, ARV resistance and the HIV-1 genetic diversity in Guinea.

Le défi de la formation dans le domaine du laboratoire de biologie clinique en Afrique

Sub-Saharan Africa has a considerable deficit in laboratory facilities. For a decade, international and national public and private initiatives have multiplied to expand both the supply and quality of medical laboratories in Africa. By 2020, the World Health Organization, with as its main operator the African Society for Laboratory Medicine, will have provided training for 30,000 laboratory personnel and encouraged 2,500 laboratories to begin the accreditation process. In addition, the World Health Organization recommendations for treatment and care of HIV-infected individuals in resource-limited settings, revised in 2013, emphasize the need for laboratory monitoring to guide antiretroviral therapy. The University Diploma in Biological Retrovirology at the Cheikh Anta Diop University in Dakar, Senegal, offers multidisciplinary training in French at the postgraduate level in the complex and diverse field of biological monitoring of HIV infection in Africa. In nearly 10 years, more than 200 African biologists have been trained.

Efficacy and Safety of Unboosted Atazanavir in Combination with Lamivudine and Didanosine in Naive HIV Type 1 Patients in Senegal

The use of ritonavir as a protease inhibitor boost is rare in sub-Saharan Africa because a heat-stable formula is not available. We report the results of an open-label pilot trial with unboosted atazanavir in combination with lamivudine and didanosine as first-line therapy conducted in Senegal. Treatment-naive HIV-1 infected adult patients without active opportunistic disease were included. The primary endpoint was the proportion of patients with plasma HIV-1 RNA <400 copies/ml at week 48. Forty patients (12 men and 28 women; mean age +/- SD: 40 +/- 9 years) were included. Treatment was changed during the study for two patients (pregnancy, tuberculosis); one patient was lost to follow-up and one patient died (gastroenteritis with cachexia). At week 48, 78% [95% confidence interval (CI): 65-90%] and 68% (95% CI: 53-82%) of the patients had HIV-1 RNA <400 and <50 copies/ml, respectively (intent-to-treat analysis; not completer = failure). Among the seven patients with HIV-1 RNA >or=400 copies/ml at week 48, five were not compliant; genotyping analysis (n = 4) did not reveal a major mutation for protease inhibitors. The mean CD4 cell count change from baseline to week 48 was +238 +/- 79 cells/mm(3). The combination of unboosted atazanavir with lamivudine and didanosine was efficient and well tolerated in HIV-1-infected patients with results similar to those observed in Northern countries. These results suggest that unboosted atazanavir with its high genetic barrier could be a valuable alternative to NNRTIs in resource-limited countries in some HIV-1-infected patients in case of compliance issues with NNRTIs, intolerance to NNRTIs, resistance mutations to NNRTIs, in women with childbearing potential, or as a maintenance therapy in patients with virological suppression.

[Decentralization of the immunological monitoring of people living with HIV/AIDS in a limiting setting with a low HIV seroprevalence: the experience of Senegal]

Our work aimed to propose a manual method of counting CD4 T lymphocytes which is an alternative magnetic immunoseparation followed by a reading with a fluorescence microscope as an alternative to the automated flow cytometry. This alternative technique is easier for use, less expensive and could answer the difficulties encountered for the monitoring CD4 T cells count in developing countries. The specific objectives were: 1) to train the technicians of the peripheral sites in order to make the numeration of the CD4 T lymphocytes more accessible at the peripheral level; 2) to equip the sites with necessary facilities for the T lymphocytes CD4 count; 3) to put in place a system of quality control permitting the reliability of the results. A hundred and fifty patients have been enrolled in three care services for people living with HIV/AIDS in Dakar. This population was constituted of 119 seropositive and 31 seronegative patients acting as control group to have some patients with high rates of T lymphocytes CD4. For the follow-up at peripheral level, the patients were constituted of the active line of the patients living with HIV/AIDS supported in the targeted sites. The measurements allowed studying concordances for different rates of lymphocytes: 0 to 199, 200 to 499 and over 500 cells by mm3. The results showed also a very good correlation (r = 0.97 or r = 0.98 according to the operator) between the two methods for CD4 rates inferior to 500 cells by mm3 among both the negative group and the HIV positive patients. We also discussed the profit of decentralization for the program and the patient, as well as the setting up of an external quality control to validate the alternative technique. According to the results, the Dynabeads is well correlated with the Facscount. It is a technique that can be used as an alternative in the zones with limited resources, low prevalence and for a small number of samples.