Cytokine expression profile in idiopathic inflammatory myopathies.
Cytokines have been shown to be potent inducers of major histocompatibility complexes (MHC) class I and II as well as of cell adhesion molecules in muscle tissue cultures, indicating that cytokines may play a role in mediating muscle fiber damage in inflammatory myopathies. We found in 21 cases of autoimmune myositis various amounts of inflammatory cells expressing interleukin (IL)-1 alpha and -beta, IL-2, IL-4, tumor necrosis factor (TNF) -alpha and -beta, and interferon (IFN)-gamma and its receptor. Muscle fibers displayed enhanced expression of IL-1 alpha and -beta, IL-2, and TNF-alpha. Upregulation of cytokines was strongest at sites of cellular infiltration typical for the respective myositis subtype. There was no correlation between the cytokine expression and the grade of inflammation. To a lesser extent, cytokines were also present in Duchenne muscular dystrophy expressed by muscle fibers positive for TNF-alpha and by phagocytic mononuclear cells. Expression of cytokines by the muscle fiber may enable the muscle fiber to induce and mediate the process of autoimmunization and antigen-expression by itself without primary presence of inflammatory cells. Cytokine-expressing muscle fibers may enhance the cytolytic potential of cytotoxic cells and the muscle fiber may serve as source and target.
Tews
D S
DS
Division of Neuropathology, Mainz University Medical Center, Germany.
Goebel
H H
HH
D016207:Cytokines / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D007249:Inflammation; D018485:Muscle Fibers, Skeletal / Q000473:pathology; D009136:Muscular Dystrophies / Q000473:pathology*; D017285:Polymyositis / Q000473:pathology
D016207:Cytokines