Serological changes in progressive systemic sclerosis.

Sera from 37 patients with scleroderma were studied for the presence of auto-antibodies. Rheumatoid factors and antibodies to smooth muscle and thyroid were seen in some patients. Ten of 31 patients (32%) had antibodies to nuclear antigens. They were not related to the extent or severity of disease but were often associated with other complications or coincidental diseases. These serological changes only occurred in the patients with progressive systemic sclerosis and did not occur in morphoea. Antibodies to double-stranded DNA were found in only one case, and neither clinical nor serological overlap with systemic lupus erythematosus were seen in this group of patients.