title: A Comprehensive Overview on Myositis-Specific Antibodies: New and Old Biomarkers in Idiopathic Inflammatory Myopathy.
abstract: Autoantibodies specific for idiopathic inflammatory myopathy (myositis-specific autoantibodies (MSAs)) are clinically useful biomarkers to help the diagnosis of polymyositis/dermatomyositis (PM/DM). Many of these are also associated with a unique clinical subset of PM/DM, making them useful in predicting and monitoring certain clinical manifestations. Classic MSAs known for over 30 years include antibodies to Jo-1 (histidyl transfer RNA (tRNA) synthetase) and other aminoacyl tRNA synthetases (ARS), anti-Mi-2, and anti-signal recognition particle (SRP). Anti-Jo-1 is the first autoantibodies to ARS detected in 15-25 % of patients. In addition to anti-Jo-1, antibodies to seven other aminoacyl tRNA synthetases (ARS) have been reported with prevalence, usually 1-5 % or lower. Patients with any anti-ARS antibodies are associated with anti-synthetase syndrome characterized by myositis, interstitial lung disease (ILD), arthritis, Raynaud's phenomenon, and others. Several recent studies suggested heterogeneity in clinical features among different anti-ARS antibody-positive patients and anti-ARS may also be found in idiopathic ILD without myositis. Anti-Mi-2 is a classic marker for DM and associated with good response to steroid treatment and good prognosis. Anti-SRP is specific for PM and associated with treatment-resistant myopathy histologically characterized as necrotizing myopathy. In addition to classic MSAs, several new autoantibodies with strong clinical significance have been described in DM. Antibodies to transcription intermediary factor 1γ/α (TIF1γ/α, p155/140) are frequently found in DM associated with malignancy while anti-melanoma differentiation-associated gene 5 (MDA5; CADM140) are associated with clinically amyopathic DM (CADM) complicated by rapidly progressive ILD. Also, anti-MJ/nuclear matrix protein 2 (NXP-2) and anti-small ubiquitin-like modifier-1 (SUMO-1) activating enzyme (SAE) are recognized as new DM-specific autoantibodies. Addition of these new antibodies to clinical practice in the future will help in making earlier and more accurate diagnoses and better management for patients.
authors.affiliation: Department of Clinical Nursing, School of Health Sciences, University of Occupational and Environmental Health, Japan, 1-1 Isei-ga-oka, Yahata-nishi-ku, Kitakyushu, Fukuoka, 807-8555, Japan. satohm@health.uoeh-u.ac.jp.
authors.forename: Minoru
authors.initials: M
authors.lastname: Satoh
authors.affiliation: Department of Human Information and Sciences, School of Health Sciences, University of Occupational and Environmental Health, Kitakyushu, Japan.
authors.forename: Shin
authors.initials: S
authors.lastname: Tanaka
authors.affiliation: Rheumatology and Clinical Immunology, Humanitas Clinical and Research Center, Via A. Manzoni 56, 20089, Rozzano (Milan), Italy.|BIOMETRA Department, University of Milan, Via Vanvitelli 32, 20129, Milan, Italy.
authors.forename: Angela
authors.initials: A
authors.lastname: Ceribelli
authors.affiliation: Department of Oral Biology, University of Florida, Gainesville, FL, USA.
authors.forename: S John
authors.initials: SJ
authors.lastname: Calise
authors.affiliation: Department of Oral Biology, University of Florida, Gainesville, FL, USA.
authors.forename: Edward K L
authors.initials: EK
authors.lastname: Chan
mesh_terms: D001323:Autoantibodies / Q000276:immunology*; D001324:Autoantigens / Q000276:immunology; D015415:Biomarkers / Q000032:analysis; D006801:Humans; D009220:Myositis / Q000276:immunology*
chemical_list: D001323:Autoantibodies; D001324:Autoantigens; D015415:Biomarkers
keywords: Anti-nuclear antibodies; Autoantibodies; Dermatomyositis; Inflammatory myopathy; Polymyositis