Absence of human leukocyte antigen-B*57:01 amongst patients on antiretroviral therapy in Nigeria: Implications for use of abacavir.

Background: The presence of human leukocyte antigen (HLA) B*57:01 allele predicts hypersensitivity reaction (HSR) to abacavir (ABC), a nucleoside reverse-transcriptase inhibitor used for human immunodeficiency virus (HIV) treatment. However, the prevalence of this allele amongst Nigerians with HIV is yet to be established. We aimed to determine the prevalence of HLA-B*57:01 allele amongst Nigerians with HIV infection. Methods: We conducted a multicentre cross-sectional epidemiologic survey. Between April 2016 and April 2017, patients were enrolled across five HIV treatment facilities in Nigeria. Participants' demographic information and their history of ABC exposure were obtained, and venous blood was obtained for HLA typing. Results: One thousand five hundred and four (1504) adults were enrolled, with a mean age of 44.6 ± 10.7 years, 1078 (71.7%) were female. 1463 (97.3%) were on antiretroviral therapy. ABC use was reported by 12 (0.8%) participants and none reported HSR. Of 1500 blood samples that were processed, 1458 (97.2%) were successfully typed. Of these, 132 (9.1%) were HLA-B*57 positive using non-specific low-resolution HLA-B*5701 primer mix. On further analysis, none of the 132 samples (0%) had the HLA-B*5701 allele. Conclusion: HLA-B*5701allele is rare amongst Nigerians.