Sicca symptoms and anti-SSA/Ro antibodies are common in mixed connective tissue disease.

Abstract

To examine a large well characterized cohort of patients with mixed connective tissue disease (MCTD) and determine longitudinally the prevalence of clinical and serologic features of Sjogren's syndrome in these patients. Patients were followed longitudinally up to 30 years with systematic clinical and serologic analysis. Sera were analyzed for reactivity with SSA/Ro, SSB/La, and snRNP polypeptide U1-70kD and for anticardiolipin antibodies. Among a well characterized patient population with MCTD, 18/55 (32.7%) had antibodies to SSA/Ro, while 2/55 (3.6%) had antibodies to SSB/La, either initially or during the course of followup. All patients had antibodies to U1-70kD small nuclear ribonucleoprotein antigen. Sicca symptoms were common, occurring in 23/55 (41.8%) patients. Patients with MCTD who were anti-SSA/Ro positive had increased incidence of malar rash (p < 0.03) and photosensitivity (p < 0.001) compared to anti-SSA/Ro negative patients. Sicca symptoms are frequent in patients with MCTD, occurring in up to one-third of the patients studied. The presence of anti-SSA/Ro antibodies identifies a group of MCTD patients with a very high incidence of malar rash and photosensitivity.