To detect evidence of abnormalities of the p53 protein in autoimmune diseases. Mutation of the p53 protein may inhibit apoptosis and thereby lead to cancer and possibly play a role in the pathogenesis of autoimmune diseases.
Serum antibodies to p53 are detected in 30 to 50% of patients with cancer who have p53 mutations. Using an ELISA, we determined the prevalence of anti-p53 antibodies in the serum of 106 patients with rheumatoid arthritis (RA), 72 patients with primary Sjögren's syndrome (SS), and 14 patients with lymphoma complicating SS. The presence of anti-p53 antibodies was also measured in the synovial fluid of 16 patients with RA. Positive sera by ELISA were confirmed by immunoprecipitation.
Serum anti-p53 antibodies were detected in 2 of 106 patients with RA. The synovial fluid of one of these 2 patients was also studied and was positive. Anti-p53 antibodies were not detected in the other synovial fluids. Serum anti-p53 antibodies were not detected in 72 patients with primary SS alone, but were present in 2 of 14 patients with lymphoma complicating SS.
Our results suggest that if p53 mutations have any role in the pathogenesis of some autoimmune diseases, they are rarely associated with the presence of anti-p53 antibodies in patients with RA. In patients with SS, the presence of serum anti-p53 antibodies might be an indirect sign of the development of a lymphoma.