ABO blood groups and risk of human immunodeficiency virus infection: A systematic review and meta-analysis.

The last few decades have seen a pandemic of human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS), which continues to cause substantial morbidity and mortality. ABO blood groups are anthropological and genetic characteristics of a population whose associations with HIV infection are still controversial. This systematic review with meta-analysis was undertaken to investigate whether certain blood groups may have associations with HIV infection. PubMed, Scopus and Web of Science databases were systematically searched as of 6 September 2021. Grey literature was identified through screening Google Scholar, and reference lists of relevant studies. All observational studies providing data on ABO blood group distribution among HIV-infected and uninfected participants were included. Using a random effect model, risk ratios (RR) and 95% confidence intervals (CIs) were pooled to quantify this relationship. Fifty eligible studies with a total of 3,068,244 participants and 6508 HIV-infected cases were included. The overall analysis found that blood group AB increased the risk of HIV infection by 19% as compared with non-AB blood groups (RR = 1.19, 95% CI: 1.03-1.39, p = 0.02). Pooled estimates for other blood groups failed to reach statistical significance. Subgroup analyses identified a positive relationship between AB blood group and HIV infection within Asia, patient populations (as opposed to blood donors and general populations), studies with lower sample sizes, high-income countries and studies with a moderate quality score. The sequential omission and re-analysis of studies within sensitivity analyses produced no change in the overall pooled effect. In conclusion, this study identified that blood group AB carriers were more susceptible to HIV infection. Future investigations should be directed toward clarification of the exact role of ABO blood groups in HIV infection and the possible underlying mechanisms.