Comprehensive evaluation of two HLA-B17 monoclonal antibodies for flow cytometry-based HLA-B57/B58 screening prior to abacavir prescription

Hypersensitivity reactions to the drug abacavir, used to treat HIV/AIDS patients, is associated with possession of HLA-B*57:01. We have carefully assessed two commercially available HLA-B57/B58 murine monoclonal antibodies [0196HA and BIH0243 (One Lambda Inc.)] in a simple flow cytometry-based assay. The evaluation involved tests on 228 reference and random samples covering 91% of all WHO recognized HLA-A, B and C specificities. These involved donors with six different HLA-B*57 alleles and included 19 examples of B*57:01. Both antibodies unambiguously detected B57, but there were small difference in their reactivity against B57-positive non-B*57:01 samples. Importantly, there was no reactivity against B57/B58-negative samples. The possible amino acid motifs involved in the reactivity of these antibodies with B57/B58 were delineated. Thus, HLA-B57/B58, normally present in <10% of patients, can be easily recognized using these two antibodies and further tested by a DNA-based typing method to identify B*57:01.