Identification of anti-DQ alloantisera correlated with DR5

Using classical serological methods, we have been able to distinguish anti-HLA-DR from anti-DQ antibodies. The specificity of alloantisera for DQ could be identified on the basis of differential reactivity against B cell and monocyte-enriched leucocyte suspensions and lack of inhibition of cytotoxicity by anti-DR monoclonal antibodies. Some alloantisera, whose reactivity was significantly correlated with DR5, were found to exhibit these characteristics. The suggestion that they recognize DQ specificities in linkage disequilibrium with DR5 was supported by immunochemical analysis.