Evolution of immunopathological diseases is usually slow and progressive. The term the undifferentiated connective tissue disease (UCTD) is used to describe the phase preceding a defined connective tissue diseases (CTD).
The objective of this work was evaluate the clinical and serological profile of patients with UCTD, who had been followed between 1994-1999. They have investigated the frequency and the type the developed autoimmune diseases from UCTD.
A total of 578 UCTD patients were evaluated.
In 143/578 patients (24.7%) with the UCTD differentiated to systemic connective tissue diseases (28 systemic lupus erythematosus, 26 mixed connective tissue disease, 19 progressive systemic sclerosis, 3 polymyositis/dermatomyositis, 45 Sjögren syndrome, and 22 systemic vasculitis). 86.7 percent (124/143) of the systemic connective disease developed in first two years of UCTD. The condition of 435/578 (75.2%) remained UCTD after 5 years, among them in 82 patients with UCTD was regression of the symptoms. The presence of the fever and anti-DNS antibodies correlated with SLE (P = 0.0104, Fisher exact test), arthritis/arthralgia and anti-RNP antibodies with MCTD (P = 0.0302), Raynaud phenomenon and ANA positivity with PSS (P = 0.0144), xerostomia/xerophtalmia and anti-SSA/SSB antibodies with Sjögren syndromes (P = 0.0144).
The UCTD in our patients seem to represents an dynamic phase, one part of the patients show progression to definite connective tissue diseases, one part show regression, and on part of the patients stay in UCTD phase.