Serum levels of interleukin-6 and interleukin-10 correlate with total skinthickness score in patients with systemic sclerosis

Various growth factors and cytokines have been suggested to play a central role in initiating and developing fibrosis in systemic sclerosis (SSc). To determine which serum levels of soluble mediators are the most relevant to the decree of skin sclerosis in SSc, serum levels of various soluble mediat ors were examined by ELISA and correlated with skin thickening that was mea sured using modified Rodnan total skin thickness scoring (TSS) system. Seru m levels of IL-4, IL-12, IL-13, tumor necrosis factor-alpha, connective tis sue growth factor (CTGF), vascular endothelial growth factor, monocyte chem otactic protein-1, macrophage inflammatory protein-1 beta, soluble IL-6 rec eptor, and soluble L-selectin were higher in SSc patients than normal contr ols. Levels of IL-6, IL-10, and CTGF in patients with diffuse cutaneous SSc were higher than patients with limited cutaneous SSc and controls. Serum l evels of IL-6 and IL-10 positively correlated with TSS in patients with SSc (r = 0.625, P < 0.0001 and r = 0.663, P < 0.0001, respectively). In additi on, IL-10 levels significantly correlated with pulmonary fibrosis. Thus, se rum levels of IL-6 and IL-10 most strongly reflect the extent of skin thick ening in SSc, suggesting that levels of IL-6 and IL-10 are useful serologic al indicators for skin fibrosis in SSc. (C) 2001 Elsevier Science Ireland L td. All rights reserved.