title: High-dose intravenous immunoglobulin therapy for rapidly progressive interstitial pneumonitis accompanied by anti-melanoma differentiation-associated gene 5 antibody-positive amyopathic dermatomyositis.
abstract: Anti-melanoma differentiation-associated gene 5 (MDA5) antibody-positive amyopathic dermatomyositis (ADM) associated with rapidly progressive interstitial pneumonitis (RPIP) frequently has a poor prognosis and optimal treatment is not well defined. Here, we report a 62-year-old Japanese man with anti-MDA5 antibody-positive ADM associated with RPIP presented with progressive shortness of breath, Heliotrope rash, Gottron's papules, arthralgia, and fatigue but no sign of muscle weakness. Laboratory investigation revealed serum levels of the following biomarkers: ferritin, 1393 ng/mL; Krebs von der Lungen-6, 1880 U/mL; and creatine kinase, 85 U/L. Computed tomography (CT) images showed diffuse ground-glass opacity in both lung fields. Because anti-MDA5 was positive, we made a diagnosis of ADM associated with RPIP and initiated treatment. Following five courses of combination therapy with prednisolone, cyclosporine A, and intravenous cyclophosphamide (IVCY), IVCY treatment was switched to high-dose intravenous immunoglobulin therapy (IVIg) because of the reactivation of interstitial pneumonia with an increased serum ferritin level. Additional treatment with IVIg improved RPIP, with normalization of anti-ADM antibody levels. Therefore, IVIg mayt be a new candidate treatment for anti-MDA5 antibody-positive ADM associated with RPIP.
authors.affiliation: Department of Endocrinology, Metabolism, Nephrology and Rheumatology, Kochi University Medical School, Kochi, Japan.
authors.forename: Kazu
authors.initials: K
authors.lastname: Hamada-Ode
authors.affiliation: Department of Endocrinology, Metabolism, Nephrology and Rheumatology, Kochi University Medical School, Kochi, Japan.
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Taniguchi
authors.affiliation: Department of Rheumatology, Misato Bay Side Medical Center, Kochi, Japan.
authors.forename: Takahito
authors.initials: T
authors.lastname: Kimata
authors.affiliation: Department of Rheumatology, Tokyo Women's Medical University, Tokyo, Japan.
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Kawaguchi
authors.affiliation: Department of Endocrinology, Metabolism, Nephrology and Rheumatology, Kochi University Medical School, Kochi, Japan.
authors.forename: Yoshiko
authors.initials: Y
authors.lastname: Shimamura
authors.affiliation: Department of Rheumatology, Nippon Medical School, Tokyo, Japan.
authors.forename: Masataka
authors.initials: M
authors.lastname: Kuwana
authors.affiliation: Department of Endocrinology, Metabolism, Nephrology and Rheumatology, Kochi University Medical School, Kochi, Japan.
authors.forename: Shimpei
authors.initials: S
authors.lastname: Fujimoto
authors.affiliation: Department of Endocrinology, Metabolism, Nephrology and Rheumatology, Kochi University Medical School, Kochi, Japan.
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Terada
keywords: Amyopathic; anti-MDA5 antibody; dermatomyositis; interstitial pneumonitis