Absence of D- alloimmunization in AIDS patients receiving D-mismatched RBCs

BACKGROUND: More than 80 percent of D- patients who receive D+ blood become alloimmunized to the D antigen. Anemia occurs in most AIDS patients at some point in the disease. D- patients with AIDS may require blood transfusion and, during times of blood shortage, may receive D+ RBCs. They would be expected to become alloimmunized to the D antigen. STUDY DESIGN AND METHODS: The records of the transfusion service between January 1996 and July 2000 were reviewed for D- patients who received D+ blood. IATs were performed before the initial transfusion and subsequently when the patient required further RBC transfusion. RESULTS: Eight D- AIDS patients who received multiple transfusions (three women and five men; age range, 31-44 years; mean, 44 years) who received between 2 and 11 units (mean, 6.25) of D+ RBCs were identified. Antibody screens were performed at 8 to 65 weeks after transfusion. It was found that none of the eight D- AIDS patients developed anti-D. ABO antibodies were found as expected. During the same period, it was found that six D- patients admitted with other diagnoses who received 1 to 9 units of D+ RBCs, all developed anti-D within 7 to 19 weeks of transfusion. CONCLUSION: Patients with AIDS may not form alloantibodies to the D antigen. This may be attributable to their immunodepressed state, particularly to the decrease in CD4+ T lymphocytes. Therefore, during blood shortages, transfusion of D+ blood to D- AIDS patients may be without any subsequent consequence.