Dermatomyositis (DM) is an idiopathic inflammatory myopathy with heterogeneous clinical manifestations. Cutaneous symptoms may or may not parallel myositis severity. Advances in myositis-specific antibodies (MSA) have refined DM diagnosis, correlating distinct subtypes with systemic involvement and malignancy risk. This study aims to highlight MSA profiles in DM.
A retrospective descriptive study included 12 patients diagnosed with DM at Cheikh Khalifa Hospital and Mohammed VI University Hospital in Bouskoura.
Among 12 patients (66.66% female, mean age 54 years), clinical manifestations were dominated by cutaneous signs (diffuse facial erythema, shawl sign, mechanic’s hands, Gottron’s papules) and proximal muscle weakness. MSA distribution: anti-Mi2 (5), anti-MDA5 (3), anti-TIF1γ (1), anti-KU (1), anti-Mi2 + anti-TIF1γ (1), inclusion myositis (1), anti-SRP, anti-MDA5 with antisynthetase syndrome. Clinical correlations: anti-Mi2: high CK levels, good prognosis, and low cancer risk. Anti-MDA5: associated with rapidly progressive interstitial lung disease (1 fatal case). Anti-TIF1γ: severe cutaneous lesions, high malignancy risk. Inclusion myositis: poor prognosis (1 fatal case). Treatment involved corticosteroids, methotrexate, and IV immunoglobulins in severe cases.
The identification of MSA subtypes has revolutionized DM classification, improving diagnosis, prognosis, and treatment strategies.
