Prevalence of HLA antibodies in transfused patients with and without red cell antibodies

BACKGROUND: Multiply transfused patients are at increased risk of developing red cell (RBC) antibodies, as well as antibodies to HLA. Although pretransfusion testing screens for RBC antibodies, no such testing is routinely performed for HLA antibodies. Determining which patients are more likely to make HLA antibodies may be important for patients undergoing elective surgery where platelets (PLTs) may be required. It is hypothesized that patients with RBC alloantibodies may be more likely to have HLA antibodies than previously transfused patients without RBC antibodies. STUDY DESIGN AND METHODS: Blood was collected from 53 adult male surgical patients with RBC alloantibodies and a control group of 69 similar male patients with a history of previous transfusions but no evidence of RBC alloimmunization. The samples were tested for the presence of immunoglobulin G Class I HLA antibodies by enzyme-linked immunosorbent assay. RESULTS: Of the 53 samples from patients with RBC alloantibodies, 12 (22.6%) also had HLA antibodies, whereas only 7 (10.1%) of the 69 patients in the control group had HLA antibodies (p < 0.03). CONCLUSIONS: There is a significant difference between the rates of HLA alloimmunization in male patients with RBC antibodies versus multiply transfused patients without RBC antibodies. Screening for HLA antibodies may be warranted in patients with RBC alloantibodies who might require PLT transfusion support for elective surgery.