Patient with rare blood group B(A) phenotype: A case report

The ABO blood group system plays a crucial role in transfusion and transplantation practices [1]. Correct identification of ABO blood group in blood donors and transfusion recipients is paramount importance for compatible transfusion of red blood cells because of minor errors can lead to fatal transfusion reactions [2,3]. Serological methods are routinely used to determine the antigens of ABO blood group system and iso-agglutinin in serum. Weak expression of A, B and H antigens on the red cell surface are often inherited or acquired. They are probably the least frequently encountered and pose a challenge in the routine immune-hematology practice [4]. In B(A) phenotype, an autosomal dominant phenotype, there is a weak A expression on group B red blood cells [5]. So, it's usually detected as an ABO discrepancy during blood group confirmation. It could be missed if only the cell grouping is performed and may lead to mislabeling of the patient/recipient blood group. This may cause hemolysis in B(A) phenotype patient if patient is transfused with A or AB Packed Red Blood Cells (PRBCs) or might end up in cross match incompatibilities. Therefore, some ABO subgroups require molecular method to identify and also to correlate the change between DNA sequence variation in the ABO gene and the quality and quantity of blood group antigens on RBCs [6]. Here we would like to share a case of probable B(A) phenotype in a patient who was diagnosed as chronic liver disease with acute pancreatitis. To the simplest of our knowledge, this is the primary report of probable B(A) phenotype in a patient from India.