Anti-Ro (SSA) antibodies in rheumatoid arthritis patients with gold-induced side effects

The purpose of our study was to investigate the significance of the presence of anti-Ro antibodies found by us in an earlier study of rheumatoid arthritis (RA) patients with gold-induced side effects. Sera of 29 anti-Ro (SSA) positive RA patients who had gold-induced side effects were studied. All sera were examined by Western blot using recombinant antigens, encoding the Ro 60 kD and the La proteins. HLA typing was done in all patients. Thirteen patients reacted only with the Ro 52 kD antigen and all had severe skin eruptions caused by gold therapy. Another ten patients who reacted only with the Ro 60 kD antigen had other side effects to gold (six had proteinuria and four leucopenia). Six patients who reacted to all three antigens (Ro 52 kD, Ro 60 kD and La) had secondary Sjögren's syndrome. No significant statistical differences were noted in the incidence of HLA-DR3 between the subgroups of patients. Our data indicated that antibodies to the Ro 52 kD antigen are associated with skin eruptions in RA patients treated with gold.