HLA antigens and adult rheumatoid arthritis: a study with a monoclonal antibody.

Adult rheumatoid arthritis (RA) is a very heterogeneous disease that is associated with HLA-antigens, although no absolute association has been found with any particular HLA type. Forty-one seropositive RA patients have been studied with a local monoclonal antibody named X1 21.4 (9w940), strongly associated with HLA-DRI, DR4, Drw10 antigens, to verify a possible correlation with the disease. The results obtained have also been compared with the data reported on MC1, a serologically defined determinant correlated with RA. X1 21.4 monoclonal antibody appears to be associated with the disease and it could identify one epitope involved in the susceptibility to RA.