title: Mechanisms of pathogenesis in scleroderma. I. Overproduction of interleukin 6 by fibroblasts cultured from affected skin sites of patients with scleroderma.
abstract: Fibroblasts were cultured from affected skin sites of patients with progressive systemic sclerosis (PSS), from unaffected skin sites of the same patients, and from a healthy donor. The concentration of interleukin 6 (IL-6) in culture medium conditioned by the growth of early passage cells was determined by radioimmunoassay and by quantitative bioassay. Results demonstrated that fibroblasts from affected PSS skin produce from 6 to 30-fold higher levels of biologically active IL-6 compared to unaffected and control cells. In contrast, serum IL-6 concentrations in 6 of 8 patients examined were not significantly different from healthy donors. Serum IL-6 levels were elevated 2 to 3-fold in 2 of 8 patients examined. Thus, the overproduction of IL-6 by affected scleroderma fibroblasts does not necessarily correlate with a systemic increase in IL-6, but may increase its concentration locally. In view of its biological activities, including stimulation of antibody production and T cell activation, the overproduction of IL-6 by PSS fibroblasts in the lesions may play a significant role in the pathogenesis of PSS and may profoundly influence the course of the disease.
authors.affiliation: Department of Microbiology and Immunology, Tulane University School of Medicine, New Orleans, LA 70112.
authors.forename: C A
authors.initials: CA
authors.lastname: Feghali
authors.forename: K L
authors.initials: KL
authors.lastname: Bost
authors.forename: D W
authors.initials: DW
authors.lastname: Boulware
authors.forename: L S
authors.initials: LS
authors.lastname: Levy
mesh_terms: D000328:Adult; D000368:Aged; D002478:Cells, Cultured; D005260:Female; D005347:Fibroblasts / Q000378:metabolism* / Q000473:pathology / Q000502:physiology; D006801:Humans; D015850:Interleukin-6 / Q000097:blood / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D011863:Radioimmunoassay; D012595:Scleroderma, Systemic / Q000209:etiology* / Q000378:metabolism / Q000473:pathology; D012867:Skin / Q000473:pathology*
chemical_list: D015850:Interleukin-6