Association of ABO and Rh blood groups with hepatitis C virus infection: a systematic review and meta-analysis

The association between ABO and Rhesus (Rh) blood groups and susceptibility to hepatitis C virus (HCV) infection remains uncertain. This systematic review and meta-analysis aimed to clarify these associations.

PubMed, Scopus, Embase, and MEDLINE were searched from inception to 23 January 2025. Studies reporting HCV infection by ABO and/or Rh blood group were eligible. Risk of bias was assessed using the NIH tools. Odds ratios (ORs) with 95% confidence intervals (CIs) were pooled using a random-effects model. Heterogeneity was assessed with the I² statistic. Subgroup, sensitivity, and publication bias analyses were also performed. The protocol was registered in PROSPERO (CRD420250635714).

Thirty-eight studies comprising 3,404,016 participants were included. No significant associations were observed for blood groups A (OR = 1.03, 95% CI: 0.97-1.10), AB (OR = 0.99, 95% CI: 0.85-1.17), O (OR = 0.94, 95% CI: 0.85-1.06), or Rh factor (OR = 0.99, 95% CI: 0.87-1.12). In contrast, blood group B was associated with an 11% higher odds of HCV infection (OR = 1.11, 95% CI: 1.02-1.22, p = 0.02). This association remained robust in sensitivity analyses. Heterogeneity was generally low to moderate, and Egger's test indicated no evidence of publication bias.

ABO and Rh blood groups were not strongly associated with HCV infection, except for a consistent positive association with blood group B. Interpretation remains limited by study design and methodological variability. Therefore, large, prospective, multi-regional studies with standardized protocols are needed to validate these findings and explore potential biological mechanisms.