Clinical implications of the presence of anti-Ro (SSA) antibodies in patients with rheumatoid arthritis.

The clinical and serologic findings in 25 patients with rheumatoid arthritis (RA) of more than 5 years' duration, who had antibodies to Ro(SSA) cellular antigen, were analyzed and compared with those in 50 anti-Ro(SSA) negative RA patients with similar disease duration. Ninety-six percent of the anti-Ro(SSA) positive patients were female, compared to 74% in the negative group. The majority of antibody positive patients had symmetric erosive synovitis, similar to that observed in the negative group. Extra-articular manifestations were similar in both groups, except for features of Sjögren's syndrome (keratoconjunctivitis sicca and positive labial salivary gland biopsy), which were significantly more common in patients with anti-Ro(SSA) antibodies. Anemia of chronic disease was also more common in these patients, as were rheumatoid factor (RF) and antinuclear antibodies (ANAs). No patient in either group had antibodies to ds-DNA or Sm and none developed clinical features suggestive of systemic lupus erythematosus (SLE). D-penicillamine, given in the majority of patients in both groups, produced adverse reactions in 72% of the anti-Ro(SSA) positive patients, but only in 27% of the negative ones. Thus, anti-Ro(SSA) antibodies seem to characterize a distinct group of RA patients who are almost exclusively female, express more activated B-cell function, have a high prevalence of Sjögren's features and commonly develop side effects to D-penicillamine.