Low frequency of observed anti-HLA among transfused preterm infants.

Background: Although low-birth-weight infants (LBWI) often receive multiple transfusions, there is controversial information on their development of antibodies against WBCs or platelets.

Study Design And Methods: A total of 52 LBWI with birth weights less than 1500 g were randomly assigned to receive either RBCs that had been WBC- reduced (n = 25) or nonfiltered blood (n = 27). Serum samples collected from 37 infants at 3 months of age and from 30 children when they were 5 to 11 years old were tested. Anti-HLA was assayed with an anti-human globulin-augmented lymphocytotoxicity test against a panel consisting of 13 lymphocytes and against parental cells.

Results: None of 52 transfused LBWI of either group developed anti-HLA (95% CI, 0%-6.8% for overall, 0%-13.7% for the WBC-reduced group, and 0%-12.7% for the nonfiltered group).

Conclusion: Multiply transfused LBWI rarely produced antibodies to HLA of blood donors and to noninherited maternal antigens. The benefits of WBC reduction to prevent HLA alloimmunization during infancy were not supported by this study and need further investigation.