title: Inflammatory myopathies with anti-Ku antibodies: a prognosis dependent on associated lung disease.
abstract: Anti-Ku antibodies have been reported in a wide spectrum of autoimmune diseases, sometimes in association with inflammatory myopathies (IM). We studied the clinical, laboratory, and muscle histologic features of all anti-Ku-positive patients detected in our hospital during the last 10 years, as well as their treatment and outcomes. Anti-Ku antibodies were found in 34 patients (0.46% of 20,600 sera positive for antinuclear antibodies), and complete data were available for 30 patients; 86.7% were female, mean age was 49 years (range, 20-73 yr). The most frequent clinical manifestations were arthralgia (77%) and Raynaud phenomenon (53%). Eleven (37%) patients had IM, 8 of them as part of an overlap syndrome defined as IM associated with connective autoimmune disease (5 systemic sclerosis [SSc], 2 Sjögren syndrome (SS), and 1 systemic lupus erythematosus [SLE]). Of 21 patients without IM, 19 had autoimmune diseases (including 6 SLE, 2 SSc, 2 SS, and 2 rheumatoid arthritis), 1 had bronchial neoplasia, and 1 had nephroangiosclerosis. Clinical features of the 9 patients with IM were myalgia (91%), proximal muscle weakness (89%), and dysphagia (36%). All had increased creatine kinase (median, 2210 U/L; range, 194-4073 U/L). Muscle biopsy showed necrosis, inflammation, and positive HLA class I immunostaining. Interstitial lung disease (ILD) was detected on computed tomography (CT) scan in 11 patients (37%) and was significantly more frequent in patients with IM (82% vs. 10.5%, p < 0.001). Fourteen (47%) patients required no immunosuppressive treatment or only a low corticosteroid dose (<15 mg/d, n = 3). A high dose of corticosteroids was more frequently administered in patients with IM (10/11 cases, 80% with associated ILD) than in patients without IM (4/19 cases, 0 with ILD). Complete muscle remission after steroids occurred in 73% of patients with IM. Lung disease was corticoresistant in 6 of 8 (75%) treated cases.Anti-Ku antibodies remain rarely detected, but their presence can be frequently associated with corticosensitive IM and severe, corticoresistant ILD.
authors.affiliation: From the Service de Médecine Interne 1 (AR, SH, OB); Département d'Immunologie (LM, JLC), Neuropathologie (OD, TM), and Radiologie (PG); Centre deRéférence des Pathologies Neuromusculaires Paris Est, Institut de Myologie(AB, SH, OB); Service de Médecine Interne 2 (ZA); Assistance Publique-Hôpitaux de Paris, Hôpital Pitié-Salpêtrière, Paris, France.
authors.forename: Aude
authors.initials: A
authors.lastname: Rigolet
authors.forename: Lucile
authors.initials: L
authors.lastname: Musset
authors.forename: Odile
authors.initials: O
authors.lastname: Dubourg
authors.forename: Thierry
authors.initials: T
authors.lastname: Maisonobe
authors.forename: Philippe
authors.initials: P
authors.lastname: Grenier
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Charuel
authors.forename: Anthony
authors.initials: A
authors.lastname: Behin
authors.forename: Serge
authors.initials: S
authors.lastname: Herson
authors.forename: Zahir
authors.initials: Z
authors.lastname: Amoura
authors.forename: Olivier
authors.initials: O
authors.lastname: Benveniste
mesh_terms: D000305:Adrenal Cortex Hormones / Q000627:therapeutic use; D000328:Adult; D000368:Aged; D000974:Antibodies, Antinuclear / Q000097:blood*; D034961:Antigens, Nuclear / Q000276:immunology*; D018771:Arthralgia / Q000209:etiology; D001323:Autoantibodies / Q000097:blood; D001327:Autoimmune Diseases / Q000150:complications; D001706:Biopsy; D003402:Creatine Kinase / Q000097:blood; D004268:DNA-Binding Proteins / Q000276:immunology*; D003680:Deglutition Disorders / Q000209:etiology; D004351:Drug Resistance; D005260:Female; D006801:Humans; D006976:Hypertension, Pulmonary / Q000175:diagnosis / Q000188:drug therapy; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D000072200:Ku Autoantigen; D017563:Lung Diseases, Interstitial / Q000175:diagnosis* / Q000188:drug therapy; D008297:Male; D008875:Middle Aged; D018908:Muscle Weakness / Q000209:etiology; D018482:Muscle, Skeletal / Q000473:pathology; D009220:Myositis / Q000150:complications / Q000188:drug therapy* / Q000276:immunology*; D009336:Necrosis; D011379:Prognosis; D011928:Raynaud Disease / Q000209:etiology; D012189:Retrospective Studies; D055815:Young Adult
chemical_list: D000305:Adrenal Cortex Hormones; D000974:Antibodies, Antinuclear; D034961:Antigens, Nuclear; D001323:Autoantibodies; D004268:DNA-Binding Proteins; D007166:Immunosuppressive Agents; D003402:Creatine Kinase; C000606509:Xrcc6 protein, human; D000072200:Ku Autoantigen