Estimation of ABO Anti-A and Anti-B Agglutinin Titers among Blood Donors at a Tertiary Care Referral Teaching Hospital Blood Centre in Southern India: A Cross-sectional Study

Introduction: Transfusion of blood Group O and its components with high ABO antibody titers to non O recipients has been shown to cause acute transfusion reactions, especially in platelet transfusions, as platelets contain significant amounts of ABO antigen on their surface as well as Anti-ABO alloisogglutinins in plasma. Aim: To estimate the ABO Anti-A and Anti-B agglutinin titers among blood donors at a tertiary care referral teaching hospital blood centre. Materials and Methods: This cross-sectional observational study was conducted at the Immunohaematology laboratory of the Department of Transfusion Medicine, Sri Venkateswara Institute of Medical Sciences, Tirupati, Andhra Pradesh, India, from March 2021 to June 2022. All blood donors presenting to the blood centre were screened for eligibility for blood donation. Donors who fulfilled the eligibility criteria as per the Drugs and Cosmetics Act, 1940, and Rules, 1945 were included. Anti-A and Anti-B titers were determined by the conventional tube method with dilutions of 1 in 2, 1 in 4, 1 in 8, 1 in 16, 1 in 32, 1 in 64, 1 in 128, 1 in 256, 1 in 512, and 1 in 1024. A titer of <64 was considered as a low titer, while a titer of >64 was considered as a high titer. Results: A total of 399 donors were included in the study, with 393 (98.5%) being males and 6 (1.5%) being females. The mean age of the study population was 28.49 years. Among blood group A, the percentage of individuals with an IgM anti-B titer of <64 was 85.44% (88) and >64 was 14.56% (15), whereas in blood group B, IgM anti-A titers of <64 were 65.5% (93) and >64 were 34.5% (49). In blood group O, the percentage of individuals with <64 and >64 titers of IgM anti-A were 52.60% (81) and 47.40% (73), respectively, whereas for anti-B, <64 and >64 titers were 77.92% (120) and 22.08% (34), respectively. Conclusion: It is recommended that a database be maintained in all institutes by estimating antibody titers for every A, B, O blood group donors. Whole blood or platelets from group O donors with IgM Anti-A and Anti-B antibody titers <64 can only be transfused across the ABO barrier. As the majority of group A donors had titers <64, group A platelets may be transfused across the ABO barrier in emergency situations.