Enhanced production of interleukin-6 (IL-6), oncostatin M and soluble IL-6receptor by cultured peripheral blood mononuclear cells from patients withsystemic sclerosis

Objectives. To determine whether the spontaneous production of interleukin 6 (IL-6), oncostatin M (OSM), soluble IL-6 receptor (sIL-6R) and soluble gp 130 (sgp130) from peripheral blood mononuclear cells (PBMC) is increased in patients with systemic sclerosis (SSc). Methods. The culture supernatants of PBMC from patients with SSc (n = 33) a nd healthy controls (n = 20) were examined by enzyme-linked immunosorbent a ssay. Results. The production levels of IL-6, OSM and sIL-6R were significantly h igher in patients with SSc than in controls. However, sgp130 levels in supe rnatants from patients with SSc were not significantly elevated when compar ed with those from controls. Soluble IL-6R levels correlated significantly with the severity of pulmonary fibrosis in patients with SSc. Conclusions. The enhanced production of IL-6, OSM and sIL-6R from PBMC may cooperatively contribute to the disease process in SSc. In particular, enha nced sIL-6R production from PBMC may be related to the development of pulmo nary fibrosis via enhancement of IL-6 signal transduction in SSc, since sIL -6R can act as an agonist of IL-6.