ABO typing error resolution and transfusion support in a case of an acute leukemia patient showing loss of antigen expression

ABO and RhD typing is an essential step before the transfusion of blood components to a patient. ABO blood group system is a significant group, which causes hemolytic transfusion reaction destroying donor red blood cells. Hence, ABO typing error should be resolved before transfusion. Especially acute leukemia patients, there is a loss of A, B, and H antigens. In this group of patients, no reaction was seen in Cell typing/forward grouping typing. An adsorption-elution study is required to support the correct blood type. Response with anti-A1, anti-AB, and anti-H in red cell typing and saliva testing is necessary to distinguish between different weak A subgroups. We presented a case of loss of A antigens and transfusion support to a leukemia patient for initiation of chemotherapy.