Bombay blood phenotype: Laboratory detection and transfusions recommendations

Four main blood types routinely identified today are A, B, AB, and O. Universal donors have type "O" blood, and have no "A" or "B" antigens. In turn, no blood reactions will occur in recipients. Conversely, universal recipients having type "AB" blood will have no antibodies to the "A" or "B" antigens. Bombay phenotype has no "A" or "B" antigens, classifying it as "O" blood type. Furthermore, Bombay phenotype lacks expression of the H antigen, which is present on every blood cell. When mixed with any type of blood other than Bombay blood, hemolytic reactions occur. A 55-year-old male had his blood typed and screened after trauma activation for an eye injury. On forward grouping, the patient was identified as blood type "O". On reverse grouping, agglutination occurred. Laboratory procedures were evaluated and an expanded antigen panel was performed which confirmed this agglutination, which led to the suspicion of a rare blood type. The patient did not require blood transfusion and was further evaluated by New York Blood Center where the diagnosis of Bombay Phenotype was confirmed. This case emphasizes the importance of proper laboratory investigations for rare blood types, preventative strategies, as well as management of Bombay blood type.