Comparing alloimmunization in preterm infants after transfusion of fresh unmodified versus stored leukocyte-reduced red blood cells

To compare the occurrence of red blood cell (RBC), platelet (PLT), and white blood cell (WBC) antibodies in preterm infants after transfusions. A randomized, blinded trial was conducted in which preterm infants were transfused either with stored RBCs, prepared by prestorage leukocyte reduction and transfused throughout 42 days of storage to limit donor exposure (n = 18), or with fresh RBCs prepared without leukocyte reduction and transfused within 7 days after collection from as many donors as needed to guarantee freshness (n = 17). Nontransfused preterm infants of comparable birth weight were control subjects (n = 11). No RBC antibodies were detected in serial blood samples taken during the first 6 months of life. Similarly, no definite WBC antibodies were found, although weak reactivity was detected transiently in sera from two infants. Accordingly, RBC and WBC antibody production did not differ among groups. In all, 11% of the transfused the infants exhibited platelet antibodies: 14% of the infants given stored leukocyte-reduced RBCs and 7% of the infants given fresh nonleukocyte-reduced RBCs (difference not statistically significant). Preterm infants rarely produce antibodies to blood cell antigens after RBC transfusions, regardless of whether the exposure is to fresh unmodified RBCs from several donors or to stored leukocyte-reduced RBCs from a limited number of donors. Therefore, efforts to limit donor exposures or to remove WBCs from blood components cannot be justified simply for purposes of preventing alloimmunization in neonates.