Serological-typing and geno-typing of blood type B(A)04 and the comparison with CisAB

Objective To identify two ABO discrepancy samples which forward typing (AweakB) and reverse typing (B) were not consistent, and to review the differences and associations with CisAB. Methods Serology and molecular biology were used to identify blood type. Cross-matching test was performed with polybrene and Liss-coombs card. Results Serology test showed that the human anti-A sera (1-2+ ) were weakly agglutinated, anti-B sera were agglutinated (4+ ), anti-A1 sera had negative reaction, anti-H were agglutinated (3-4+ ) on red blood cell of the two subjects. However, red blood cells of the two subjects had no agglutination with human plasma type B by tube agglutination assays. The reverse typing of the two cases showed agglutination only with A1c (3-4+ ), but not with A2c, Bc, Oc, and their own red blood cells. Molecular biology trail showed that 2 subjects were determined as B(A)04/O01. Cross-matching test showed no hemolysis and agglutination of B and O type washed red blood cell. Conclusions Both of the two cases were determined as B(A)04 subtype. Type O and type B washed red blood cell can be transfused into them, and type AB plasma and low titer group B plasma are feasible. Key words: B(A) blood group; CisAB blood group; AweakB type