ABO blood grouping discrepancies in the donor population

Abstract

Background and Objectives ABO discrepancies occur when the reactions in forward grouping are not corroborative to those in the reverse grouping due to weak subgroups of A and/or B, missing or weak ABO antibodies or unexpected alloantibodies. We aimed to determine the prevalence of ABO discrepancies in our donor population and to know the causes by using a standard classification. Materials and Methods It was a retrospective study on donor samples. For all the discrepant samples, the ABO and RhD grouping was repeated using tube technique. Adsorption–elution testing was done for detecting weak subgroups of A and B. Antibody screen (3‐cell) and identification (11‐cell) were done by gel technique (Bio‐Rad, Switzerland). Results We detected 93 (0·064%) ABO discrepancies out of the total 144279 donor samples tested. The ABO discrepancies were due to weak anti‐B antibody (33/93; 35·5%), weak anti‐A antibody and weak subgroups of A (24 each; 25·8% each) and weak subgroups of B (5/93; 5·4%). Agglutination with O cells was observed in 7 (7·5%) samples at room temperature testing. The alloantibodies identified in these samples were anti‐M (5) and anti‐Lea in (1), while the remaining 1 sample was of ‘Bombay’ (Oh) phenotype. The autologous control was negative for all the samples. Conclusion The prevalence of ABO discrepancies in our donor population is 0·064%.

Analysis of Blood Group Discrepancy in Healthy Blood Donors at a Tertiary Care Referral Hospital from Eastern India: A Retrospective Study

“…Similar studies done by other authors from different parts of our country ( Table 3 ) have shown that the prevalence of ABO discrepancy ranges from 0.02 to 0.064%. 1 2 4 8 We observed a little higher prevalence rate of ABO discrepancy in comparison to the other studies. Genetic diversity along with a demographic variation of the population in this part of the country could be a possible explanation of the different prevalence rate of ABO discrepancy.…”

“…A recent study done by Jain et al and a study by Sharma et al observed that type I ABO discrepancy accounted for the predominant type of ABO blood group discrepancy with a percentage frequency of 35.5 and 58.8%, respectively. 4 8 Moreover, both the studies found that weak or low avidity anti-B antibody is the most common cause of type I ABO blood group discrepancy. The changes of ABO isoagglutinin levels related to age, immunodeficiency conditions, and other clinical conditions like post-hematopoietic stem cell transplant are few possible causes of weak or missing reactivity of antibodies in the reverse grouping.…”

“… 2 12 However, Makroo et al and Jain et al reported that subgroups of A antigen were the second most common cause that contributed to 29 and 25.8%, respectively. 1 4 A small proportion of A population contains subgroups of A antigen. These subgroups have fewer antigen sites on the RBC that result in weakened or even missing reactions in forward grouping.…”

“… 2 13 We did not observe any weak B subgroup that is perhaps because the subgroup of B is much less common than the subgroup of A as mentioned in the previous studies. 4 12 …”

“…Correct assignment of blood group not only prevents ABO mismatch blood transfusion but also helps in providing correct blood product in ABO mismatch organ transplant and prevents organ rejection. 4 However, blood group discrepancies still occur during routine blood transfusion practices. Blood group discrepancies are usually encountered when there is a deviation from the expected pattern of antigen in cell grouping and antibody in serum grouping.…”