Determination of ABO antibody titre and haemolysin test of group O whole blood used for exchanged transfusion in a teaching hospital.

Background: Group O blood donor is more readily available and is frequently used as a universal red cell donor and emergency O whole blood (EM O) for exchange transfusion in neonates. Sera from group O donors contains two separable haemolysin antibodies, anti-A and anti-B, and a cross-reacting antibody called anti-A, B (mostly IgG). The presence of haemolysins in the donors may lead to haemolysis in the recipients. Objectives: This study aims to determine the prevalence of anti-A and anti B haemolysins and titer among group O donors that we screened for emergency group O (EM O) whole blood.Methodology: A cross sectional study was done to determine the prevalence of anti-A and anti B haemolysin and titer among group O blood donors screened for EM O whole blood for exchange transfusion in neonates at a teaching hospital from January to December 2018. Samples of 350 voluntary group O regular donors were selected for ABO antibodies titration and haemolysin test using the conventional tube technique at room temperature. Donors were screened for titer of 1:50 and 1:100 only. ABO antibody titer of ≥1:100 was considered as a high titer and not suitable for exchange transfusion. Titer of ≤1:50 were labeled as EM O whole blood and will be suitable for exchange transfusion. Results: A total of 350 group O blood donors were screened for the anti A and anti B haemolysin and titer. The majority of blood group O donors were male (n=215, 61%) and were age from 18-30 years old (51%). Malay was the predominant group (83%). About 52.9% of the donors were low titer (≤1:50), and 47.1% were high titer (≥1:100). Low titer was seen predominantly among male donors (61.8%). The prevalence of haemolysins in group O donors was 5.4% (n=19). Anti A and anti B haemolysins were seen in 0.57% and 2.28% of the donors, respectively, while donors having both A and B haemolysins in their sera was 2.57%. Conclusion: Prevalence of anti-A and anti-B haemolysins were low among group O blood donors. However, a significant percentage of group O donors have high titer of anti-A or anti-B. Therefore, despite the labour intensiveness of haemolysis titration technique and the frequent transfusion of group O blood for exchange transfusion, there is the need to routinely screen our donors for haemolysins in order to identify those posing the greatest risk to recipients. [ABSTRACT FROM AUTHOR]