Transforming growth factor-beta 1 in polymyositis and dermatomyositis correlates with fibrosis but not with mononuclear cell infiltrate.
The idiopathic inflammatory myopathies are diseases of unknown etiology characterized by T cell-mediated myocytotoxicity in polymyositis and complement-mediated angiopathy of muscle fibers in dermatomyositis. A variable degree of fibrosis is present in muscles in these conditions both perimysially and endomysially. We evaluated the expression of TGF-beta 1, a pleiotropic cytokine with fibrogenic and immunomodulating activity, by means of quantitative-polymerase chain reaction and immunocytochemistry in DM and PM muscle biopsies. TGF-beta 1 mRNA was significantly higher in DM compared with controls, whereas in PM the values were not significantly different when compared with controls and DM. TGF-beta 1 was localized in connective tissue but did not correspond with mononuclear cell infiltrates. These findings suggest a correlation between TGF-beta 1 and connective tissue proliferation in inflammatory myopathy, while its immunomodulatory role remains to be elucidated.
Confalonieri
P
P
Department of Neuromuscular Diseases, National Neurological Institute C., Besta, Milan, Italy.
Bernasconi
P
P
Cornelio
F
F
Mantegazza
R
R
D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D003238:Connective Tissue / Q000378:metabolism / Q000473:pathology; D003882:Dermatomyositis / Q000378:metabolism* / Q000473:pathology*; D005355:Fibrosis; D006801:Humans; D007150:Immunohistochemistry; D008875:Middle Aged; D009000:Monocytes / Q000473:pathology; D009132:Muscles / Q000378:metabolism / Q000473:pathology; D016133:Polymerase Chain Reaction; D017285:Polymyositis / Q000378:metabolism* / Q000473:pathology*; D012333:RNA, Messenger / Q000378:metabolism; D016212:Transforming Growth Factor beta / Q000235:genetics / Q000378:metabolism*
D012333:RNA, Messenger; D016212:Transforming Growth Factor beta