Undifferentiated connective tissue disease in a rheumatology center in Cali, Colombia: clinical features of 94 patients followed for a year.

The aim of the study is to evaluate the clinical and serological features of patients with undifferentiated connective tissue disease (UCTD) of a rheumatology referral center in Cali, Colombia, who were followed for a year. A retrospective analysis of a cohort of patients with an initial diagnosis of UCTD and monitoring for at least 12 months was carried out. A total of 94 patients with UCTD (97.9% women) were evaluated, with an average follow-up of 51 ± 35.7 months. Only 13 patients (13.8%) evolved into a defined connective tissue disease (CTD), of which 8.5% (n:8) developed systemic lupus erythematosus (SLE), 4.2% (n:4) Sjögren syndrome (SS) and 1.1% (n:1) rheumatoid arthritis (RA). A mean period of 35.8 ± 29.2 months between UCTD diagnosis and definite develop of a CTD was found. Arthritis, Raynaud's phenomenon and photosensitivity were statistically significant (<0.001) for development of CTD. After a mean follow-up of 4.25 years, most of the patients with UCTD showed a favorable evolution. Arthritis, Raynaud's phenomenon and the presence of photosensitivity were predictors for the development of CTD. It requires a consensus to establish criteria for the classification of UCTD.