Background The objective of this study was to evaluate the effect of CYP2B6 and CYP3A4 polymorphisms on the virological and immunologic responses of patients receiving an efavirenz-containing regimen. A total of 153 HIV-positive patients were enlisted for the current study.

Methods Viral load and median CD4 T cell counts were evaluated at baseline and month 6 (M6). Single nucleotide polymorphisms (SNPs) in CYP2B6 and CYP3A4 genes were genotyped using TaqMan genotyping assays.

Results Interestingly, the AG genotype in CYP2B6 rs2279343 was associated with viral load suppression (VLS) compared to the homozygous AA (OR 2.6; 95% CI 1.3–5.3). Moreover, in the overdominant model, the AG genotype was associated with VLS compared to AA/GG (OR 2.05; 95% CI 1.3–2.9). The AG genotype in CYP2B6 rs2279343 was associated with an increase in CD4 cell count between baseline and M6 (p = 0.01). In CYP2B6 rs3745274, CD4 cell count at M6 was higher than that of baseline for GG carriers (p = 0.04) and for GT carriers (p = 0.013). In contrast, the TT mutant displayed no difference in CD4 cell count at M6 and baseline (p = 0.3). In CYP3A4 rs2740574, the TC carriers showed a higher median CD4 count at M6 compared to that of the baseline count (p = 0.024), similar trend was noted for CC carriers (p = 0.004). In contrast, the TT genotype showed no trend (p = 0.8). The best genotypes combination associated with CD4 cell count improvement were AA/AG in SNP rs2279343 (p = 0.003) and GG/GT in SNP rs3745274 (p = 0.002).

Conclusion Our findings support the fact that CYP2B6 rs2279343 could help in the prediction of VLS and both SNPs rs3745274 and rs2279343 in CYP2B6 and CYP3A4 rs2740574 were associated with immune recovery in Malian HIV-positive patients.