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

Summary 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 ‐ B 57/ B 58 murine monoclonal antibodies [0196 HA and BIH 0243 ( O ne L ambda I nc.)] 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 B 57, but there were small difference in their reactivity against B 57‐positive non‐ B *57:01 samples. Importantly, there was no reactivity against B 57/ B 58‐negative samples. The possible amino acid motifs involved in the reactivity of these antibodies with B 57/ B 58 were delineated. Thus, HLA ‐ B 57/ B 58, 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.