Type III procollagen N-terminal propeptide, soluble interleukin-2 receptor, and von Willebrand factor in systemic sclerosis

Objective To evaluate the blood concentration of type III procollagen N-terminal prop eptide (PIIINP), soluble interleukin-2 receptor (sIL-2R), and von Willebran d factor (VWF) in systemic sclerosis (SSc) patients. Methods PIIINP sIL-2R, and vWF were measured in the sera and plasma of 29 SSc patie nts and 29 sex and age-matched healthy controls. Serum PIIINP was determine d by radioimmunoassay. Both serum sIL-2R and plasma vWF were measured by en zyme-linked immunosorbent assay (ELISA). Associations between concentration s and clinical and laboratory features were evaluated. Results Serum levels of PIIINP and sIL-2R were significantly higher in the SSc grou p than in the control group (p < 0.01 for both). No differences in serum PI IINP and sIL-2R levels were found between the limited and diffuse cutaneous subsets. However PIIINP concentrations were significantly higher in anti-S cl-70 positive SSc patients compared with those of anti-Scl-70 negative pat ients (p = 0. 01). Serum PIIINP levels were significantly higher in SSc pat ients with restrictive pulmonary function (FVC < 80%) than in patients with normal pulmonary function (p < 0.05). The correlation between PIIINP level s and FVC (p < 0.05) was negative, but the correlation between PIIINP level s and modified Rodnan skin scores (p < 0.05) was positive. sIL-2R levels we re not correlated with skin and pulmonary involvement of SSc. There was no difference in vWF levels between those of the SSc patients and those of the control groups. Conclusion These results suggest that serum PIIINP serves as a biologic marker for the extent of skin and pulmonary involvement in systemic sclerosis. Increased serum levels of sIL-2R in SSc patients support a role for T lymphocyte acti vation in the pathogenesis of systemic sclerosis.