Undifferentiated connective tissue disease with antibodies to Ro/SSa: clinical features and follow-up of 148 patients

OBJECTIVE: To evaluate the clinical and serologic profile, the rate of progression to well defined CTD and the possible predictors of disease evolution in patients affected by UCTD with antibodies anti-RoISSA. METHODS: 148 patients diagnosed as UCTD were retrospectively evaluated. Antibodies to SSA/Ro were determined by counter-immunoelectrophoresis and ELISA. RESULTS: Thirty-six patients (24.3%) developed a well-defined CTD after a mean follow-up of 4.5 years. Most patients developed primary Sj?gren's syndrome (SS) (50%) or systemic lupus erythematosus (SLE) (30.5%). Leukopenia and xerophthalmia developed more frequently in the group of patients evolving to defined CTDs (p < 0.0032 and p < 0.0063). Leukopenia independently predicted the evolution in CTD by multivariate regression analysis (p < 0.019). Anti-dsDNA predicted the evolution in SLE (p < 0.0207), while the presence of additional anti-ENA specificity to anti-Ro/SSA was not associated with the outcome. CONCLUSION: 24.3% of patients with UCTD and antibodies to Ro/SSA can progress in a relatively short period of time to well-defined CTDs. The development of primary SS could be predicted by xerophthalmia and SLE by the appearance of anti-dsDNA antibodies.