Identification and analysis of a rare CisAB group

Abstract

Incompatible ABO transfusion can lead to immune hemolytic transfusion reaction. Accordingly, a correct ABO subgroup identification is vital for blood transfusion safety. ABO subgroups are often characterized by their abnormal appearances and a weakening or disappearance of antigens or antibodies, resulting in mismatched forward and reverse typing. This is mainly caused by ABO gene mutations, leading to a decrease in A/B transferase activity. This makes ABO subgroups prone to misidentification, which has an important impact on the safety and efficacy of transfusion. The CisAB group is one of such ABO subgroups with a complex phenotype, which due to various factors is difficult to determine using routine serological testing. Here, one CisAB group case in the Dongguan Blood Center was identified and reported as follows.