Development of connective tissue disease in patients presenting with Raynaud's phenomenon: a six year follow up with emphasis on the predictive value of antinuclear antibodies as detected by immunoblotting.

Eighty five patients referred because of Raynaud's phenomenon (RP) were followed up for six years. Every two years they were screened for signs and symptoms of connective tissue disease (CTD) according to a protocol, and serum was stored. Initially, 30 patients had primary RP, 16 had one symptom of CTD ('possible CTD'), 18 had two or more symptoms ('probable CTD'), and 21 had definite CTD (14 of whom had scleroderma). Most of the symptoms were related to scleroderma. There was an insidious progression to scleroderma or CRST syndrome (calcinosis, Raynaud's phenomenon, sclerodactyly, telangiectasia): 11 of 46 patients with primary RP or possible CTD developed probable scleroderma (two or more symptoms but not fulfilling all criteria), and seven of 13 patients with probable scleroderma developed definite scleroderma or CRST. The presence of distinct antinuclear antibodies (ANAs) as detected by immunoblotting in patients with primary RP and possible CTD at the start of the study was associated with the evolution of symptoms of CTD (chi 2 = 5.7, p less than 0.01). In patients initially with primary RP or possible CTD the antibody specificities of ANAs as determined by immunoblotting had prognostic value for the development of certain disease entities: anticentromere (CR-19) for CRST (sensitivity 60%, specificity 98%) and antitopoisomerase I (Scl-70 or Scl-86) for scleroderma or probable scleroderma (sensitivity 38%, specificity 100%).