Human immune-response, D-related antigen encoded by the D locus on chromosome 6 and found on lymphoid cells. It is in linkage disequilibrium with HLA-A1 and HLA-B8. The HLA-DR3 antigen is strongly associated with celiac disease, Grave's disease, dermatitis herpetiformis, early-age onset myasthenia gravis, systemic lupus erythematosus, juvenile diabetes, and opportunistic infections in AIDS.