Evaluation of immunoglobulin M and immunoglobulin G titers of ABO blood group system in blood donors at a blood center of a tertiary care hospital.

BACKGROUND AND OBJECTIVES: ABO antibodies have implications in platelet transfusions, solid organ, and bone marrow transplants. The study aimed at measuring the immunoglobulin G (IgG) and immunoglobulin M (IgM) ABO antibody titers in A, B, and O blood group blood donors and correlating the titers with age, gender, and blood group of donors. SETTINGS AND DESIGN: A prospective observational study was performed over 3 years at a tertiary care blood center. MATERIALS AND METHODS: Equal number of A, B, and O group blood donor samples chosen by random sampling were evaluated for titers by doubling dilution using tube method. IgM titers were determined at room temperature. IgG titers were tested at 37°C with anti-IgG antiglobulin reagent after inactivating IgM antibodies by dithiothreitol. The titers were correlated with age, gender, and blood group. STATISTICAL ANALYSIS: Mann-Whitney U-test, Kruskal-Wallis test, and Bonferroni correction were employed for various correlations using IBM SPSS v26 (Statistical Package for the Social Sciences) software. A two-tailed P < 0.05 was considered statistically significant. RESULTS: A total of 870 samples (290 of each of A, B, and O blood groups) were tested for IgG and IgM antibody titers. IgG anti-A and anti-B titers were significantly higher in blood group O as compared to blood groups B and A. Anti-B IgM titers in group A were significantly higher than anti-A IgM titer in B. The antibody titer showed decreasing trend with age. There was no correlation with gender. CONCLUSIONS: The study will help hospitals and blood centers in formulating policies regarding ABO antibody titer estimation in platelet donors and renal transplant recipients in the context of out-of ABO group platelet transfusions and ABO-incompatible renal transplants, respectively.