Serological analysis of Bm subtype: a case report

Bm subtype is relatively rare in clinical practice. In this article, the serological analysis of one case of Bm subtype was identified. The microcolumn gel method indicated a discrepancy between the forward and reverse typing. The forward typing was type O, whereas the reverse typing was type A. Antibody screening test yielded negative results. Absorption and release experiments confirmed that weak B antigen was present in the red blood cells. Moreover, the red blood cells did not react with anti-A, B serum, suggesting the existence of Bm subtype. This case prompted that serological analysis of blood type should be performed at the presence of a discrepancy between the forward and reverse typing. Appropriate blood type should be infused according to the blood subtype to guarantee the safety of blood transfusion.