Prevalence of anti‑A and anti‑B hemolysis among blood group O donors in Lagos

Background: Group O donor blood is more readily available and is frequently used as universal red cell donor in our environment. The presence of hemolysins in the donors may however lead to hemolysis in the recipients. Attempts have been made to study the prevalence of hemolysins in various populations with results from our environment showing wide variation (20–80%).Aims: To determine the prevalence and titer of anti‑A and anti B hemolysins among blood donors at the Lagos University Teaching Hospital and compare results with that obtained elsewhere. Determine if the practice of transfusion of group O blood to nongroup O recipients is permissible in this environment.Materials and Methods: Test for hemolysis was done using the standard tube method. Samples positive for hemolysis were then scored and titrated with the titers read visually and photometrically at 540 nm.Results: Three hundred and fifty blood group O donors with age range 18–58 years and median age of 28 ± 8.4 years were enrolled in the study. The overall prevalence of anti‑A and/or anti‑B hemolysins obtained was 30.3%. Prevalence of anti‑A and anti‑B hemolysins only was 15.4% and 5.1% respectively whereas both anti‑A and anti‑B hemolysins were present in 9.7% donor samples. Though anti‑A hemolysins were more prevalent than anti‑B hemolysins, anti‑B hemolysins had higher mean visual (6:7) and spectrophotometric titers (81:101). A visual titer of 8 and above which is considered significant was seen in 18.6% of donor samples.Conclusion: Anti‑A and anti‑B hemolysins exist in significant frequencies and titers among blood group O donors in Lagos. It is recommended that the use of group O donor blood for recipients who are non‑O be discouraged. Clinical studies to determine the frequency and severity of hemolysis in non‑group O recipients of blood group O are required.Key words: Anti‑A and anti‑B hemolysins, blood donors, blood group O, prevalenc