Resolution of blood group discrepancy and serological evaluation of weak B phenotype in a healthy blood donor: A case report from West Bengal.

Several weaker subgroups of B have been described (e.g. B3, Bx, Bm, and Bel) which are very infrequently encountered. These subgroups show weaker and variable serologic reactivity with the commonly used human polyclonal antisera, thus causing group discrepancy and dilemma to resolve these problems and mismatch blood transfusion. Here, we present a case of weak B subgroup detected in a 40-year-old male voluntary blood donor. His red cells showed weak agglutination with anti-B and anti-AB, and in his serum, there were potent anti-A and weak anti-B which were not detected at 37°C. After adsorption with anti-B, an eluate was prepared from the patient's cells which agglutinate with B and AB cells but did not agglutinate with A or O cells. His probable blood group is Bx. With special serological testing, a rare group is detected and decision is made to provide blood to the right patient at the right time.