Fornaro M, Coladonato L, Giannini M, Napoletano A, Girolamo F, D'Abbicco D, Ruggieri M, Sabella DVA, Iannone F. Anti-SAE dermatomyositis: clinical and histologic characteristics from a monocentric Italian cohort.
Clin Exp Rheumatol 2024;
42:295-301. [PMID:
38488098 DOI:
10.55563/clinexprheumatol/110r0p]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Accepted: 02/13/2024] [Indexed: 03/19/2024]
Abstract
OBJECTIVES
Multiple myositis-specific antibodies have been identified, each associated with different clinical subsets of dermatomyositis (DM). Anti-SAE associated DM is considered the least studied subset. Our study aimed to evaluate the clinical and histological characteristics of DM patients with anti-SAE antibodies. As reference, patients with anti-Mi2 antibodies associated DM, representing a well-characterised subset, were analysed.
METHODS
We recorded data from our DM cohort in the INflammatory MYositis REgistry (INMYRE). Patients were divided into two groups: those positive for anti-SAE and those positive for anti-Mi2 antibodies. Clinical characteristics, including skin, muscle, and extra-muscular involvements, were recorded. Available muscle biopsies were compared between the two groups.
RESULTS
Of 92 DM patients, 10 (10.9%) were positive for anti-SAE and 17 (18.5%) for anti-Mi2. Anti-SAE positive DM patients showed classic DM findings but were characterised by a higher prevalence of skin itching (60% vs. 11.8%, p<0.01), shawl sign (40% vs. 5.9%, p<0.05) and lung involvement (30% vs. 0%, p<0.05) compared to anti-Mi2 positive patients. Furthermore, anti-SAE positive DM patients showed lower creatine kinase levels than those with anti-Mi2 (median [IQR]: 101 [58-647] vs. 1984 [974-3717], p<0.05) and a lower percentage of muscle fibre degeneration and necrosis (1.5%±1.7 vs. 5.9%±3.2, p<0.05) in muscle biopsies. No other differences were observed.
CONCLUSIONS
Anti-SAE DM represents a disease subset characterised by classic cutaneous involvement often associated with itching, less severe muscle involvement, but potential pulmonary involvement that should always be investigated in these patients.
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