Benveniste et al., Paris, France Therapy

of polymyositis and dermatomyositis I. Marie, Rouen, France As reminded by D. Hilton-Jones in this issue’s review [1], the classification of myositides is currently changing. Since 1975, when Peter and Bohan [2] defined the diagnostic criteria for polymyositis (PM) and dermatomyositis (DM), the development of new pathological tools [3] and [4] permitted to refine the diagnosis criteria, but also, together with fundamental research in immunology [5] and neurosciences [4] to approach the various physiopathological events leading to the different acquired inflammatory and/or autoimmune myopathies. Beside the now “classical and well recognized” PM and DM, new insights have been this website done for the recognition of inclusion body myositis (IBM) [4] that must be distinguished from PM, but also, for the recognition of immune-mediated necrotizing myopathies (IMNM) [5] that clearly differ from inherited myopathies or dystrophies [6]. Among IMNM, some are related to the presence of particular specific auto-antibodies (anti-SRP), others are associated with neoplasia and the remaining are also recognized [7] for their property to be treatable by immunosuppressants. The recent discovery of a new auto-antibody specifically SNS-032 solubility dmso associated to IMNM (neither paraneoplastic,

nor anti-SRP positive) [8] highlights the potential toxic trigger role of statins in the genesis of IMNM/myositis, since the presence of this antibody was frequently associated with statin exposure [8]. A few weeks later, the same team also discovered

and published else the target of this antibody, which is the 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR) [9], the key enzyme in the cholesterol biosynthetic pathway specifically inhibited by statins. They also showed that statins up-regulate the expression of HMGCR on regenerative muscle fibers [9] (HMGCR being the major target of autoantibodies in statin-associated IMNM). Undoubtedly, commercial kits for the routine dosage of this auto-antibody will soon be available, facilitating the diagnosis of this condition. We will then see if all the myopathies due to the statins are due to the presence of this antibody. In the same vein, during the past few years, the burden of the dosages of the different myositis-specific (or associated) auto-antibodies has increased, an important step forward, since it may facilitate, at a modest cost, the diagnosis of these diseases. Within a very short time, we have now a routine access to the dosage of different antisynthetase antibodies anti-J0-1 (histidyl-tRNA synthetase), PL-7 (threonyl-tRNA synthetase), PL-12 (alanine-tRNA synthetase), OJ (isoleucil-tRNA synthetase), EJ (glycyl-tRNA synthetase), but also of anti-SRP, Mi-2, Ku, PM-Scl, RNP antibodies.