RESUMO
OBJECTIVE: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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.
