Inflammatory Myopathy + Mitochondrial Pathology in muscle (IM-Mito), subtype of IM-VAMP

Immune/Antibody

antibody/infmyop.htm#Inflammatory Myopathy + Mitochondrial Pathology in muscle (I

Overview

From WUSTL Neuromuscular

Clinical Onset age: Mean 61 years; Range 43 to 71 years Weakness Quadriceps: Early & most severe (90%) Proximal: Legs > Arms Distal (40%): Wrist & Finger flexion Face (50%) Symmetric (70%) Progression: Slow Overall weakness: 1% to 4% per year Knee extension: 3% to 8% per year Slower than IBM May develop IBM phenotype Treatment Long term: No clear benefit Methotrexate Dose: 10 to 20 mg/week More effective: Patients with < 10% of fibers COX- Patients unresponsive to treatment may have IBM on repeat muscle biopsy Corticosteroid therapy: NO response Laboratory Serum CK: Normal or mildly elevated;