Plasma somatomedin-C levels in systemic sclerosis.

We have measured the plasma levels of somatomedin-C (SM-C) or insulin-like growth factor I (IGF-I) in 13 patients with progressive systemic sclerosis (PSS) and age and sex matched healthy controls. We found the plasma SM-C levels to be within normal limits in all the patients. Thus, if somatomedin-C plays a role in the pathogenesis of PSS, it is more likely to be at the fibroblast receptor level or in the synthetic response of fibroblasts to SM-C.