The Role of ABO Blood Group Antigens in Recurrent Vaginitis: A Retrospective Analysis

INTRODUCTION: This study aimed to investigate the relationship between ABO blood groups, hematological inflammatory indices, and vaginal culture results in women with recurrent vaginitis, focusing on the potential role of blood group antigens in susceptibility to gynecological infections.
METHODS: We retrospectively analyzed reproductive-age women with ≥4 vaginitis episodes per year. Patients with complete clinical and lab data were included; those who were pregnant, immunosuppressed, had malignancy, or recent antifungal/antibiotic use were excluded. Vaginal culture results were evaluated against inflammatory indices and ABO/Rh blood groups. Statistical analyses used Mann-Whitney U and Fisher-Freeman-Halton Exact Test.
RESULTS: Among pathogen-positive cases, ABO blood groups were distributed as A 54.7%, O 37.3%, B 6.7%, and AB 1.3%, with a significant association between blood group and pathogen type (p = 0.004). All Neisseria gonorrhoeae and Klebsiella isolates, and most Streptococcus species, occurred in blood group A. Candida albicans appeared in all blood groups, more frequently in O, especially with bacterial vaginosis. Rh positivity was 84% and not significantly associated with pathogens. Gravida and parity were higher in pathogen-positive patients (p = 0.027 and 0.021). Pruritus, vaginal discharge scores, and annual infection frequency were higher in patients with normal vaginal flora. No significant differences were observed in systemic inflammatory markers.
DISCUSSION AND CONCLUSION: ABO blood groups, particularly group A antigens, may increase susceptibility to vaginal pathogen colonization in recurrent vaginitis. Given the limited diagnostic utility of systemic inflammatory indices, maintaining the vaginal microenvironment and normal flora is critical for effective clinical management.

Keywords: Recurrent vaginitis, ABO blood group, Vaginal microbiota