Blood transfusion using unmatched ABO blood types can result in patient death due to intravascular hemolytic reactions followed by immunological and biochemical changes. Considering the small number of studies on anti-A and anti-B hemolysins and the relevance of these antibodies in the transfusional practice, this work aimed at assessing the frequency of these hemolysins and their relationship to factors such as ethnic background and gender in blood donors of blood banks located in Itapeva and Ourinhos, São Paulo State, Brazil. All samples from type O donors recorded in these two blood banks with high serum levels of hemolysins (donations considered high-risk) were analyzed. Data related to hemolysin frequencies, ethnicity, gender and origin of blood donors were collected. The frequency of donors belonging to the high-risk O blood group was 1.2% in Itapeva and 5.3% in Ourinhos. In Ourinhos the risk of a Caucasian donor being positive for hemolysin is 2.16 times higher than other ethnic groups and in Itapeva, it was observed that the risk is lower for Caucasians than other ethnic groups. Regarding the gender, in Ourinhos the risk of a donor being positive to hemolysin is 1.82 times greater in men and in Itapeva the risk is higher in women. The ratios of gender and ethnic background in respect to frequency were different between the two regions. Thus it is important for blood banks to be aware of regional variations.
Hemolysins; dangerous O donor; transfusion reaction; ABO hemolytic antigens
