ABSTRACT
BACKGROUND: Primary immune response against red blood cell (RBC) antigens often takes weeks or months to be detected. In previous reports, for children receiving multiple units of blood components, ranging from five to 81 units, the elapsed time between the first RBC transfusion and antibody detection ranged from 18 to 78 days. Cytomegalovirus (CMV) is sometimes associated with immunohaematologic findings and may modulate immune response. CASE REPORT: A 24-week-old male infant with interstitial pneumonia and hepatitis because of CMV developed an RBC auto antibody and two RBC alloantibodies: anti-Jka, detected in tube 11 days after a single RBC transfusion, and anti-K, detected only in papain gel test 18 days later. CONCLUSION: As anti-Jka is not a naturally occurring antibody, this is the most rapid primary immune response against an RBC antigen after a single RBC transfusion ever described, in the youngest child ever described.
