Background: Blood group discrepancy is a discrepancy in the results of the cell grouping with serum grouping examination. The source of discrepancy is from technical errors or a patient's medical status such as age, disease, history of blood transfusion and medication, pregnancy. This case study aims to evaluate a discrepancy of blood group A with missing antigen in anorectal malformation patient at Dr. Wahidin Sudirohusodo Hospital, Makassar, Indonesia
Case Presentation: A male baby, 6 months 19 days old, was unable to defecate since birth post-colostomy. Physical examination reveals anemia. A routine blood test showed a hemoglobin level of 8.8 g/dL. The diagnosis was high position anorectal malformation post colostomy suspect Hirschsprung Disease, with 110 cc Packed Red Cell (PRC) transfusion plan. A routine pre-transfusion procedure was performed. It was found a discrepancy of blood group A with missing antigen. Crossmatching with blood groups O and A both gave compatible results. Examination of peripheral blood smear after PRC blood group A transfusion found no signs of hemolytic.
Conclusion: Blood group discrepancy, in this case, was due to missing antigen, which was caused by the possibility of gastrointestinal bacterial infection.