The idiopathic inflammatory myopathies are diseases of unknown etiology characterized by T lymphocytemediated myocytotoxicity in polymyositis (PM) and complement-mediated angiopathy of muscle fibers in dermatomyositis (DM). Since a connective tissue proliferation has been described in PM and DM both perimysially and endomysially, we evaluated the expression of fibrogenic and immunomodulating cytokine TGF-βl by quantitative-polymerase chain reaction and immunocytochemistry in 11 DM and 8 PM muscle biopsies. We found significantly higher TGF-βl mRNA level in DM (0.46 ±0.45 fg/200 ng total RNA) than in controls (0.12 ±0.33) (P = 0.036), while in PM the cytokine level (0.33 ±0.19) did not differ significantly either from controls (P = 0.102) or DM (P = 0.487). By immunostaining TGF-βl was present in proliferated connective tissue but not in relation to mononuclear cell infiltrates. These findings suggest an active role of TGF-βl in fibrotic process in PM/DM muscles. Current studies on basic fibroblast growth factor (bFGF) and platelet-derived growth factor (PDGF) may give new insights on the fibrogenic and immunomodulatory activity of these cytokines in inflammatory myopathies.
|Number of pages||1|
|Journal||Italian Journal of Neurological Sciences|
|Publication status||Published - 1997|
ASJC Scopus subject areas
- Clinical Neurology