The purpose of this study was to investigate the expression of IL-1 receptors and their ligands in muscle tissue from patients with myositis and from healthy controls.
Because IL-1alpha and IL-1beta, and the anti-inflammatory competitive inhibitor, IL-1 receptor antagonist (IL-1Ra), have been implicated in the pathogenesis of myositis, we assessed the role of variable number tandem repeat (VNTR) polymorphisms of the IL-1Ra gene (IL-1RN) in the aetiology of JIIM: IL-1RN VNTR polymorphisms were performed on 250 JIIM patients and 471 race-matched controls and were correlated with clinical characteristics.
The findings suggest that in IM muscle a sustained secretion of cytokines by T cells or of IL-1 by macrophages is not a prerequisite for operation of the immune effector response and that muscle may not be the site of ongoing sensitization.