Numerous host-related factors have influenced the highly diverse clinical outcomes of the coronavirus illness 2019 (COVID-19), which is caused by SARS-CoV-2. Among these, the Rh factor and the ABO blood group system have garnered a lot of interest as possible risk factors that cannot be changed. The evidence from throughout the world examining the relationship between ABO and Rh blood types and COVID-19 susceptibility, severity, and outcomes is compiled in this review. Blood group O seems to offer some protection, most likely because of the presence of anti-A antibodies and higher IgG levels, whereas data from several studies indicate that blood group A is associated with a higher risk of infection and unfavorable results. Results for blood groups B and AB are still mixed, with some research suggesting increased vulnerability. In addition, compared to Rh-positive people, Rh-negative people show a decreased risk of infection and serious illness. Conflicting findings are caused by methodological variances, regional variances, and study population heterogeneity. While blood group A and Rh-positive status are linked to greater vulnerability, blood group O and Rh-negative status appear to be protective overall. To elucidate processes and enhance the therapeutic significance of these relationships, more multicenter and genetically stratified research is needed.
Patil et al. (Wed,) studied this question.