Immunologic response in treatment-naïve HIV-2-infected patients:the IeDEA West Africa cohort

Introduction: Response to antiretroviral therapy (ART) among individuals infected with HIV-2 is poorly described. We compared the immunological response among patients treated with three nucleoside reverse-transcriptase inhibitors (NRTIs) to boosted protease inhibitor (PI) and unboosted PI-based regimens in West Africa. Methods: This prospective cohort study enrolled treatment-naïve HIV-2-infected patients within the International Epidemiological Databases to Evaluate AIDS collaboration in West Africa. We used mixed models to compare the CD4 count response to treatment over 12 months between regimens. Results: Of 422 HIV-2-infected patients, 285 (67.5%) were treated with a boosted PI-based regimen, 104 (24.6%) with an unboosted PI-based regimen and 33 (7.8%) with three NRTIs. Treatment groups were comparable with regard to gender (54.5% female) and median age at ART initiation (45.3 years; interquartile range 38.3 to 51.8). Treatment groups differed by clinical stage (21.2%, 16.8% and 17.3% at CDC Stage C or World Health Organization Stage IV for the triple NRTI, boosted PI and unboosted PI groups, respectively, p=0.02), median length of follow-up (12.9, 17.7 and 44.0 months for the triple NRTI, the boosted PI and the unboosted PI groups, respectively, p<0.001) and baseline median CD4 count (192, 173 and 129 cells/µl in the triple NRTI, the boosted PI and the unboosted PI-based regimen groups, respectively, p=0.003). CD4 count recovery at 12 months was higher for patients treated with boosted PI-based regimens than those treated with three NRTIs or with unboosted PI-based regimens (191 cells/µl, 95% CI 142 to 241; 110 cells/µl, 95% CI 29 to 192; 133 cells/µl, 95% CI 80 to 186, respectively, p=0.004). Conclusions: In this observational study using African data, boosted PI-containing regimens had better immunological response compared to triple NRTI combinations and unboosted PI-based regimens at 12 months. A randomized clinical trial is still required to determine the best initial regimen for treating HIV-2 infected patients

Cutting edge: resistance to HIV-1 infection among African female sex workers is associated with inhibitory KIR in the absence of their HLA ligands

NK cells are regulated in part by killer Ig-like receptors (KIR) that interact with HLA molecules on potential target cells. KIR and HLA loci are highly polymorphic and certain KIR/HLA combinations were found to protect against HIV disease progression. We show in this study that KIR/HLA interactions also influence resistance to HIV transmission. HIV-exposed but seronegative female sex workers in Abidjan, Côte d'Ivoire, frequently possessed inhibitory KIR genes in the absence of their cognate HLA genes: KIR2DL2/KIR2DL3 heterozygosity in the absence of HLA-C1 and KIR3DL1 homozygosity in the absence of HLA-Bw4. HIV-seropositive female sex workers were characterized by corresponding inhibitory KIR/HLA pairings: KIR2DL3 homozygosity together with HLA-C1 and a trend toward KIR3DL1/HLA-Bw4 homozygosity. Absence of ligands for inhibitory KIR could lower the threshold for NK cell activation. In addition, exposed seronegatives more frequently possessed AB KIR genotypes, which contain more activating KIR. The data support an important role for NK cells and KIR/HLA interactions in antiviral immunity

Impact of genotypic drug resistance mutations on clinical and immunological outcomes in HIV-infected adults on HAART in West Africa.

OBJECTIVES: To analyse the association between the presence of resistance mutations and treatment outcomes. The impact of HIV-1 drug resistance mutations in African adults on HAART has so far never been reported. METHODS: In 2004 in Abidjan, C?d'Ivoire, 106 adults on HAART had plasma viral load measurements. Patients with detectable viral loads had resistance genotypic tests. Patients were followed until 2006. Main outcomes were serious morbidity and immunological failure (CD4 cell count < 200 cells/microl). RESULTS: At study entry, the median previous time on HAART was 37 months and the median CD4 cell count was 266 cells/microl; 58% of patients had undetectable viral loads, 20% had detectable viral loads with no major resistance mutations, and 22% had detectable viral loads with one or more major mutations. The median change in CD4 cell count between study entry and study termination was +129 cells/microl in patients with undetectable viral loads, +51 cells/microl in those with detectable viral loads with no mutations and +3 cells/microl in those with detectable viral loads with resistance mutations. Compared with patients with undetectable viral loads, those with detectable viral loads with resistance mutations had adjusted hazard ratios of immunological failure of 4.32 (95%CI 1.38-13.57, P = 0.01). One patient died. The 18-month probability of remaining free of morbidity was 0.79 in patients with undetectable viral loads and 0.69 in those with resistance mutations (P = 0.19). CONCLUSION: In this setting with restricted access to second-line HAART, patients with major resistance mutations had higher rates of immunological failure, but most maintained stable CD4 cell counts and stayed alive for at least 20 months