Anti-NXP-2 Dermatomyositis What? DM with generalized subcutaneous edema Pts have more myalgias, more severe weakness, and an increased prevalence of dysphagia than dermatomyositis patients without these autoantibodies. How? • Antibodies targeting NXP-2 Manifestations: • Progressive myalgia • Proximal and distal muscle weakness • Generalized nonpitting edema • Subcutaneous calcinosis • Dysphagia • Significant weakness in the neck Cutaneous Manifestations: Less likely to have typical DM skin manifestations. But can still have: • Periorbital heliotrope (blue-purple) rash with edema • Erythematous rash on the face, or the anterior chest (in a V-sign), and back and shoulders (in a shawl sign) • Violaceous papules or plaques located on the dorsal part of the MCP or interphalangeal joints: Gottron’s papules • Palmar papules: can be associated with hyperkeratosis, and complicated of ulcerations • Skin ulcerations • Auricular skin lesions: antihelix/helix violaceous macules and erythematous auricular papules Clinical and Biological Features of Anti-NXP2 Dermatomyositis: • Muscle atrophy may cause weakness without increasing CK levels • NXP-2 antibody positive had more severe disease with muscle contractures, atrophy, and diminished functional status Labs: Elevated levels of: • Serum CPK - not always elevated • Aldolase • Myoglobin Association of Anti-NXP2 Dermatomyositis With Malignancy: Associated with Malignancy: • Papillary carcinoma • Clear cell renal carcinoma • Colon adenocarcinoma • Non-small-cell lung carcinoma • Waldenstrom's macroglobulinemia Lung Manifestations of Anti-NXP2 Dermatomyositis: • ILD was diagnosed in 7% of anti-NXP-2-positive patients Treatment of Anti-NXP2 Dermatomyositis: • Prednisone at 1 mg/kg per day • In severely ill patients, pulse dose methylprednisolone 1 g/day for three days #AntiNXP2DM #AntiNXP2 #Dermatomyositis #diagnosis #management #rheumatology #dermatology
