Abstract

 Background and Objectives

 ABO typing discrepancies in blood donors are not properly considered in Iran, and the only solution to this problem is to exclude the blood unit without any reasonable explanation to blood donor. In this study we examined 75066 blood units of Isfahan Blood Transfusion Center in 15 months for ABO discrepancies in order to evaluate the prevalence and relevant factors of this complication.

  Materials and Methods

 Cell and back typing were conducted in a descriptive study on blood donors’ red clots and sera. Special serological tests were done while observing ABO discrepancies to identify the correct blood group. Relevant factors were evaluated using existing data and information obtained from blood donors’ consultation sessions. Data analysis was performed by utilizing Chi-square test.

 Results

 We found 41 cases of ABO discrepancies (0.054%) that were more prevalent among men of 41 to 50 years of age with O blood group (p<0.5, p<0.1, p<0.1). The most important reason for these discrepancies was low titer of anti B in serum samples (41.46%) that made confused results in ABO back typing. Low levels of antigen concentration on red cell membrane (34.16% including 50% for A antigen and 50% for B antigen), presence of naturally occurring cold agglutinins in blood sera (12.19%), and errors made by technicians in detecting agglutinations(12.19%) were other reasons in this regard. In autologous controls, we identified 6 cases of warm autoantibody in sera. Autoantibodies did not interfere with ABO typing: one case was drug induced and others were idiopathic nevertheless, such blood donors were referred to hematological clinicians. 83.3% of cases had additional cold agglutinins and one was low-titered natural ABO antibody.

 Conclusions

 35 saved blood units in this study indicate the importance of considering ABO discrepancies in blood transfusion centers which is necessary for both blood donors and recipients. The presence of autoantibodies in healthy blood donors is recommended to be further studied.

 Key words: ABO discrepancy, Cell typing, Back typing, Blood donor