New insights in pathogenesis and therapy of sporadic inclusion body myositis (s-IBM)

Sporadic inclusion body myositis (s-IBM) is a chronic progressive inflammat ory myopathy which occurs preferentially in alder patients. Histologic hall marks are rimmed vacuoles and eosinophilic cytoplasmatic inclusions. The et iology is still unknown, but different pathogenetic mechanisms such as slow virus infection, autoimmunopathogenesis, myonuclear alterations, and mitoc hondrial defects have been implicated. A relation to neurodegenerative diso rders and prion diseases has also been suggested. There is a poor response if any to immunosuppressive therapy. Stabilization of disease progression w as shown only by intravenous immunoglobulin (IVIG) therapy. Future findings in the field of s-IBM pathogenesis may result in better therapeutic option s.