SERUM CONCENTRATION OF PROCOLLAGEN TYPE-I CARBOXYTERMINAL PROPEPTIDE IN SYSTEMIC-SCLEROSIS

The serum level of procollagen type I carboxyterminal propeptide (P1CP ), which has been used as an index of collagen synthesis in patients w ith various fibrotic diseases during the active stage, was measured us ing enzyme-linked immunosorbent assay in 61 patients with systemic scl erosis (SSc) and in 21 control subjects. The mean P1CP level in the SS c patients was significantly higher than in the normal controls (mean +/- SD, 326 +/- 319 vs 128 +/- 87 ng/ml; p < 0.005). In 36% of the SSc patients, the serum P1CP level was significantly elevated more than t wo standard deviations above the mean control value. The mean serum P1 CP level in patients with diffuse SSc was significantly higher than in those with limited SSc (411 +/- 373 vs 255 +/- 199 ng/ml; p < 0.05). In addition, the SSc patients with elevated serum P1CP levels showed a significantly greater incidence of lung fibrosis and joint involvemen t than those with normal P1CP levels (p < 0.005 and p < 0.05, respecti vely). These results suggest that the serum P1CP level is a useful ind icator of the severity of disease in SSc patients.