Prevalence of Human Leukocyte Antigen (HLA)-B*57:01 in HIV-Infected Patients

Abstract

Deaths related with human immunodeficiency virus (HIV) infections have been decreased by the introduction of combined anti-retroviral therapy (ART) into the clinical practice. Combined ART usually consists of two nucleoside/nucleotide analogs reverse transcriptase inhibitors (NRTI) that is called backbone and a third drug that belongs to either non-nucleoside/nucleotide reverse transcriptase inhibitors (NNRTI), protease inhibitors (PI), integrase strand transfer inhibitors (INSTI) or entry inhibitors. During abacavir therapy which is a member of NRTI, hypersensitivity reactions can occur approximately 4-9% of the patients that lead difficulties for the management of HIV infections. It is known that, the development of hypersensitivity reactions to abacavir is strongly associated with the presence of HLA-B*57:01 allel, therefore, HLA-B*57:01 screening should be performed prior to abacavir use. Since there is no data on HLA-B*57:01 prevalence in HIV-1-infected cases in Turkey, this is the first study that screened HLA-B*57:01 allels among HIV-1 infected adults in Turkey. A total of 100 HIV-1-infected patients (81 male, 19 female; mean age: 42.31 +/- 11.97 years) who have admitted to the Department of Infectious Diseases and Clinical Microbiology of Ondokuz Mayis University School of Medicine, Samsun, Turkey, were included in the study. Genomic DNAs were isolated from the blood samples of patients by using a commercial spin column procedure (QIAamp (R) DNA Blood Mini Kit; QIAGEN GmbH, Germany). HLA-B*57:01 genotyping was performed by the method of sequence-specific primer (SSP)-based amplification using a commercial OlerupSSP (R) HLA-B*57:01 high-resolution test kit (Olerup SSP AB, Sweden) according to the manufacturer's protocol. The products of polymerase chain reaction were electrophoresed on a 2% agarose gel stained with Olerup SSP GelRed dye (Olerup SSP AB, Sweden), and the bands were evaluated under UV light. In our study, three (2 male, 1 female) out of 100 patients were found positive for HLA-B*57:01 gene with a prevalence of 3%, which is a moderate level. Although the medical usefulness of HLA-B*57:01 screening before the abacavir therapy is emphasized, it was also noted that this application is not cost-effective for the populations with low HLA-B*57:01 prevalence, in contrast to populations with high prevalence. Considering of the incidence of HIV/AIDS in Turkey which is 0.12, the value and cost-effectiveness of HLA-B*57:01 screening in HIV-1 positive cases before abacavir therapy should be analysed by further studies.