Prevalence of minor mutations and natural polymorphisms at the protease gene among treatment-naïve human immunodeficiency virus-1 infected individuals in Jos, Nigeria

Abstract

Background: Minor mutations to protease inhibitors often occur as polymorphisms in the protease gene in non-B human immunodeficiency virus (HIV)-1 subtype among antiretroviral (ARV) treatment-naive patients. Aims: This study sought to determine the prevalence of minor mutations occurring in the protease gene among ARV naive HIV-1 infected patients in Jos, Nigeria. Settings and Design: We retrospectively analyzed specimen of 105 patients recruited between October 2010 and April 2011 at the HIV clinic, Jos University Teaching Hospital, Nigeria. Materials and Methods : Genotypic testing was done using an in-house genotyping system at the Kenya Medical Research Institute HIV-Research Laboratory in Kisumu, Kenya; HIV-1 viral resistance mutations assessed using Stanford HIV drug resistance database and classified using International acquired immunodeficiency syndrome (AIDS) Society (IAS)-USA list of mutations. In additional, viral subtypes were determined using REGA subtyping tool v.2.0 and CD4 levels by flow cytometry. Statistical analysis: Prevalence of mutations was computed and participants' baseline clinical and biological properties summarized by percentages for categorical variables and mean/median for quantitative variables. Results: Of the 105 samples, 100 were successfully amplified. HIV-1 subtypes identified were circulating recombinant form (CRF) - CRF02_AG (48.0%), G (41.0%), CRF06_cpx (6.0%) and A1 (5.0%). The most prevalent minor mutations among the patients occurred at positions L89M (96%), M36I (93%), K20I (77%), V82I (39%), E35Q (29%), L63P (25%) and polymorphisms at I13V (99%), R41K (86%), H69K (86%), K14R (67%). One sample presented with a major PI resistance mutation (Q58E). Conclusions: We found high rates of minor mutations and polymorphisms in circulation, possibly reflecting the drug naivety of participants. In addition, there was an evidence of transmitted drug resistance, hence targeted genetic resistance testing should be considered in national treatment guidelines.