HLA-C: Plasma viral load and antibiotic susceptibility pattern of microbial infection in HIV-1 among serodiscordant couples in Nigeria

Background: The role Human Leucocyte Antigen-C class I play in microbial infections and antibiotic susceptibility among heterosexual HIV-1 serodiscordant couples is not known in Nigeria. Therefore, this study evaluated the association between HLA-C Class I, microbial infection, antibiotic susceptibility in HIV-1 transmission amongst heterosexual serodiscordant couples in Nigeria. Methods and materials: A total of 271 serodiscordant who signed informed consent document were enrolled into this study. Extracted genomic DNA was sequenced on exons 2 and 3 DNA for both high and low resolutions of HLA-C class 1 genotyping using allele-specific primers. Baseline and follow-up HIV-1 RNA (plasma viral load), CD4+ count analysis was done for HIV positive individuals. One hundred and twenty-six (126) High vaginal/endocervical swabs, 11 urethral swabs and 137 early morning urine samples passed through: microscopy, culture, Antibiotics susceptibility test and other identification methods. Results: Participants age ranged from 20 to >50 years with median age of 38 years. Two hundred and eight (208) etiologic agents were isolated and Candida spp. 56 (26.9%), Staphylococcus aureus and Escherichia coli 46 (22.1%) respectively were the most prevalent. Staphylococcus aureus showed more sensitivity to Augmentin (95.4%) and Gentamycin (90.4%) and more resistance to Ceftazidime and Gentamycin (81.4%/72.3%). HLA-C*040101 72 (34.5%)/C*0701 57 (24.2%) and C*040101 106 (39.0%)/C*0701 86 (31.6%) were the most prevalent alleles associated with high plasma viral load at baseline and after 6 months on ARV (p<0.000, p<0.003). Sexually transmitted infections (STIs) and Reproductive tract infections (RTIs) were associated with increased plasma viral load (p < 0.057/p > 0.071). HLA-C*070201 22 (9.0%) was independently associated with HIV-1 susceptibility (p < 0.006) among Serodiscordant Couples. Conclusion: High plasma viral load was significantly associated with STIs and RTIs which was independently associated with resistance to Ceftazidime and Gentamycin. The HLA-C alleles which has increased chances of HIV-1 transmission from HIV positive Index to the recipient Partner is also significantly associated with high plasma viral load. Seriologic HLA-C*070201, was the allele associated with HIV-1 susceptibility based on polymorphism in HLA-C class 1 genetic markers in serodiscordant couples in Nigeria.