The presence of unexpected alloantibodies (antibodies against red cell antigens) in patient serum found in pretransfusion screening of recipients is 0.7%-1.6%. This averages 9% (range, 6%-36%) in multitransfused patients. Infants less than 4 months old usually do not form alloantibodies against transfused red cell antigens that they lack. After that, age per se does not […]