title: Anti-PL7 antisynthetase syndrome under interferon therapy.
abstract: A 62-year-old woman with a past history of chronic hepatitis C virus infection presented an atypical predominantly painful polymyositis following a flu-like syndrome, persisting despite the withdrawal of PEG-interferon alpha-2b therapy. Clinical assessment, then immunological, electrophysiological and iconographic investigations including myositis antibodies, electromyography, pulmonary functions assessment and thoracic CT-scan found respectively "mechanic hands", arthralgia, presence of antisynthetase anti-PL7 antibody, typical myographic features of hip and shoulder girdles involvement, pulmonary fibrosis and restrictive syndrome features. A deltoid muscle biopsy revealed an unclassified myositis getting closer to anti-J0-1 and connective tissue disease associated myositis featuring: some components of polymyositis, dermatomyositis, and the following peculiar pathological aspects: noncaseous granulomatous infiltrate, endomysial microangiopathy and vascular and sarcolemic deposition of complement membrane attack complex. The diagnosis of interferon induced anti-PL7 antisynthetase syndrome with microangiopathic and granulomatous overlap myositis was retained. A treatment associating intravenous immunoglobulin and moderate tapered oral corticosteroids allowed a complete long-term resolution of myositis and a clear improvement of pulmonary involvement. This case points out the wide range of interferon alpha-associated disorders and call for a precise and detailed immunopathological analysis of myositis, instead of the usual vague classification as idiopathic polymyositis or dermatomyositis about antisynthetase syndrome.
authors.affiliation: Department of Adult Haematology, Necker-Enfants malades Hospital, Assistance publique-Hôpitaux de Paris, université Paris-Descartes, 149, rue de Sèvres, 75015 Paris, France. achille.aouba@orange.fr
authors.forename: Achille
authors.initials: A
authors.lastname: Aouba
authors.forename: Sophie
authors.initials: S
authors.lastname: Georgin-Lavialle
authors.forename: Benjamin
authors.initials: B
authors.lastname: Terrier
authors.forename: Loïc
authors.initials: L
authors.lastname: Guillevin
authors.forename: François-Jérome
authors.initials: FJ
authors.lastname: Authier
mesh_terms: D000998:Antiviral Agents / Q000009:adverse effects*; D001323:Autoantibodies / Q000276:immunology; D005260:Female; D019698:Hepatitis C, Chronic / Q000188:drug therapy* / Q000276:immunology; D006801:Humans; D000077190:Interferon alpha-2; D016898:Interferon-alpha / Q000009:adverse effects*; D008875:Middle Aged; D009220:Myositis / Q000139:chemically induced / Q000276:immunology; D011092:Polyethylene Glycols / Q000009:adverse effects*; D011994:Recombinant Proteins; D013914:Threonine-tRNA Ligase / Q000276:immunology*
chemical_list: D000998:Antiviral Agents; D001323:Autoantibodies; D000077190:Interferon alpha-2; D016898:Interferon-alpha; D011994:Recombinant Proteins; D011092:Polyethylene Glycols; D013914:Threonine-tRNA Ligase; C417083:peginterferon alfa-2b