Clinical and Serological Studies in Patients with “Unclassified” Connective Tissue Disease

Fourteen patients with unclassified connective tissue disease (UCTD) were presented. All patients were followed for above two years from the initial diagnosis and duration of disease were from 2 to 23 years. The certain clinical features were characterized by non-erosive polyarthritis and Raynaud's phenomenon appearing transiently and recurrently.They never had swollen hand, sausage like fingers, esophageal disturbance which commonly occur in patients with mixed connective tissue disease (MCTD). None of patients developed systemic lupus erythematosus (SLE), progressive systemic sclerosis (PSS) and MCTD. 9 had hyper gammaglobulinemia, rheumatoid factor was positive in 9, serum test for syphilis was biological false positive in 2, Coombs direct test was positive in 4, LE cell test was positive in 5, speckled type antinuclear antibody was positive in all patients.Antibody to ribonucleoprotein was positive in 6, but antibody to RNase resistant ENA in only one.Renal biopsies were performed in 8 of 14, and light microscopies showed mild mesangial hypercellularity with normal capillary loops in 6 and showed no remarkable change in 2. IgG, IgM and C3 were detected in 4 of 8 by direct immunofluorescence.In summary, UCTD is different from MCTD, other connective tissue diseases and their pre-syndrome.