Five-year follow-up of 165 Italian patients with undifferentiated connective tissue diseases

Objective To study those conditions with a proven or hypothesised immunologic pathoge nesis and denominated under a working definition of undifferentiated connec tive tissue diseases (UCTD). Methods A multicentre prospective study was organised involving 10 tertiary referra l centers of internal medicine in Italy, with the aim of describing the nat ural history of UCTD and the prevalence of its different clinical and immun ological manifestations. Results After a five-year follow-up period, data on 165 patients were available for analysis. UCTDs occur mainly in females in their fourth decade of life. Ar ticular and mucocutaneous features and Raynaud's phenomenon represent the m ost common findings. Nevertheless, we also detected a relatively high incid ence of permanent major organ damage. Regarding the immunologic parameters, we documented some conflicting results in the correlation between serologi c abnormalities and clinical features, In 10 patients UCTD evolved to a maj or disease, generally systemic lupus erythematosus or Sjogren's syndrome. Conclusion A low rate of evolution to a defined autoimmune disease, the limited use of steroid or immunosuppressive therapy, and a favourable course in the major ity of cases are the main characteristics of patients with UCTDs.