Cross-reactive antigens and HLA matching.

Anti-HLA-A2 and anti-B17 reactivity of 87 broadly reactive sera was studied by inhibition of monoclonal Ab binding. These Abs were detected as often in patients bearing Ags cross-reactive with A2 or B17 as in those not bearing such Ags. These results indicate that predictions of negative cross-matches based on Ag cross-reactivity or reactivity against public epitopes will not be accurate in a high proportion of cases.