Objectives: The anti-melanoma differentiation-associated gene 5 (MDA5) antibody is the main predictor of interstitial lung disease (ILD) in DM and clinically amyopathic DM (CADM). Nevertheless, a subset of MDA5+ patients have a favourable prognosis. We aimed to determine the possibility of using anti-MDA5 antibody isotypes and IgG subclasses for evaluating ILD risk.
Methods: The isotypes (IgG, IgA and IgM) of anti-MDA5 were detected in serum samples of 36 anti-MDA5+ patients with DM/CADM using ELISA. IgG subclasses of anti-MDA5 antibodies were further investigated. Laboratory findings and cumulative survival were analysed based on the isotypes of anti-MDA5 and subclasses of anti-MDA5 IgG.
Results: Among the MDA5+ patients with DM/CADM, the positive rates of anti-MDA5 IgG, IgA and IgM were 100, 97 and 6%, respectively. The positive rates of anti-MDA5 IgG1, IgG2, IgG3 and IgG4 were 72, 25, 0 and 28%, respectively. The incidence of acute interstitial pneumonia, mortality rate and serum ferritin were significantly higher in anti-MDA5 IgG1+ patients than in anti-MDA5 IgG1- patients with DM/CADM (P = 0.0027, 0.015, 0.0011, respectively). The sensitivity and specificity of anti-MDA5 IgG1 for predicting mortality were 100 and 41.7%, respectively. A combination of anti-MDA5 IgG1 and IgG4 for predicting mortality yielded better specificity (87.5%).
Conclusion: IgA and IgG are the primary anti-MDA5 antibody isotypes. Anti-MDA5 IgG1 is the primary component of MDA5 IgG subclasses and anti-MDA5 IgG1 and IgG4 might serve as useful biomarkers for predicting mortality in DM-ILD.
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http://dx.doi.org/10.1093/rheumatology/keab268 | DOI Listing |
Dermatologie (Heidelb)
February 2025
Klinik für Dermatologie, Allergologie und Venerologie, Universitätsklinikum Leipzig, Philipp-Rosenthal-Str. 23, 04103, Leipzig, Deutschland.
Painful ulcerations developed in a 33-year-old woman with anti-NXP-2-positive dermatomyositis in the facial and trunk areas and a 67-year-old woman with TIF1-gamma-positive dermatomyositis on the hands, while undergoing systemic therapy with azathioprine or low-dose methylprednisolone and cyclic administration of intravenous immunoglobulins (IVIG), respectively. In the laboratory workup, the anti-MDA‑5 antibody status remained negative and the creatine kinase (CK) normal in both patients, while histopathological examinations were nonspecific. Intensive topical class 4 corticosteroid therapy and continuation of the immunosuppressive or immunomodulating therapy led to healing of the ulcerative skin lesions.
View Article and Find Full Text PDFClin Rheumatol
July 2024
Department of Immunology and Rheumatology, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Vasco de Quiroga 15, Mexico City, México, 14080.
J Med Virol
March 2024
Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), Institute for Viral Hepatitis, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China.
Juvenile dermatomyositis (JDM) is a rare systemic autoimmune disease characterized by cutaneous findings, muscle inflammation, and vasculopathy. Patients with antimelanoma differentiation associated gene 5 (anti-MDA5) JDM may have subtle muscle weakness, absence of pathognomonic rashes, and more polyarthritis and ulcerative skin lesions when compared with other JDM subtypes. Although there is a known association of rapidly progressive interstitial lung disease (RP-ILD) in patients with anti-MDA5 dermatomyositis, few case reports describe this association in the pediatric literature.
View Article and Find Full Text PDFClin Rheumatol
November 2022
Department of Rheumatology, The Second Affiliate Hospital of Zhejiang University School of Medicine, Hangzhou, 310009, China.
Objectives: The purpose of this study was to determine the incidence of myositis-specific autoantibodies (MSAs) in a cohort of Chinese patients with idiopathic inflammatory myopathies (IIMs) and to examine their associations with clinical characteristics and long-term prognosis.
Methods: Adult patients with confirmed IIMs (n = 515) were studied using the EUROLINE Autoimmune Inflammatory Myopathies 16 Ag (IgG) commercial line blot test to detect MSAs/myositis-associated autoantibodies. We collected the laboratory data and clinical features.
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