title: Single-specificity anti-Ku antibodies in an international cohort of 2140 systemic sclerosis subjects: clinical associations.
abstract: Autoantibodies directed against the Ku autoantigen are present in systemic sclerosis (SSc) and have been associated with myositis overlap and interstitial lung disease (ILD). However, there is a paucity of data on the clinical correlates of anti-Ku antibodies in the absence of other SSc-specific antibodies. The aim of this study was to assess the clinical correlates of single-specificity anti-Ku in SSc.An international (Canada, Australia, USA, Mexico) cohort of 2140 SSc subjects was formed, demographic and clinical variables were harmonized, and sera were tested for anti-Ku using a line immunoassay. Associations between single-specificity anti-Ku antibodies (i.e., in isolation of other SSc-specific antibodies) and outcomes of interest, including myositis, ILD, and survival, were investigated.Twenty-four (1.1%) subjects had antibodies against Ku, and 13 (0.6%) had single-specificity anti-Ku antibodies. Subjects with single-specificity anti-Ku antibodies were more likely to have ILD (58% vs 34%), and to have increased creatine kinase levels (>3× normal) at baseline (11% vs 1%) and during follow-up (10% vs 2%). No difference in survival was noted in subjects with and without single-specificity anti-Ku antibodies.This is the largest cohort to date focusing on the prevalence and disease characteristics of single-specificity anti-Ku antibodies in subjects with SSc. These results need to be interpreted with caution in light of the small sample. International collaboration is key to understanding the clinical correlates of uncommon serological profiles in SSc.
authors: Department of Medicine, McGill University, Montreal, Quebec, Canada Lady Davis Institute, Jewish General Hospital, Montreal, Quebec, Canada Division of Rheumatology, Jewish General Hospital, Montreal, Quebec, Canada Division of Rheumatology, Hopital du Sacre-Coeur de Montreal, Montreal, Quebec, Canada Department of Medicine, Université de Montréal, Montreal, Quebec, Canada Rheumatology Unit, Royal Adelaide Hospital, Adelaide, Australia Discipline of Medicine, University of Adelaide, Bedford Park, Australia Department of Allergy and Immunology, Flinders Medical Centre, Bedford Park, Australia Department of Rheumatology, St. Vincent's Hospital Melbourne, Fitzroy, Victoria, Australia Department of Medicine, The University of Melbourne at St. Vincent's Hospital, Melbourne, Victoria, Australia Division of Rheumatology and Immunogenetics, University of Texas Health Science Centre at Houston, Houston, TX Faculty of Medicine, University of Calgary, Calgary, Alberta, Canada.
authors: S
authors: S
authors: Hoa
authors: M
authors: M
authors: Hudson
authors: Y
authors: Y
authors: Troyanov
authors: S
authors: S
authors: Proudman
authors: J
authors: J
authors: Walker
authors: W
authors: W
authors: Stevens
authors: M
authors: M
authors: Nikpour
authors: S
authors: S
authors: Assassi
authors: M D
authors: MD
authors: Mayes
authors: M
authors: M
authors: Wang
authors: M
authors: M
authors: Baron
authors: M J
authors: MJ
authors: Fritzler
mesh_terms: D001168:Arthritis / Q000453:epidemiology; D001323:Autoantibodies / Q000097:blood*; D015897:Comorbidity; D005260:Female; D006801:Humans; D006976:Hypertension, Pulmonary / Q000453:epidemiology; D000072200:Ku Autoantigen / Q000276:immunology*; D017563:Lung Diseases, Interstitial / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009220:Myositis / Q000453:epidemiology; D015995:Prevalence; D012189:Retrospective Studies; D012595:Scleroderma, Systemic / Q000453:epidemiology / Q000276:immunology*
chemical_list: D001323:Autoantibodies; D000072200:Ku Autoantigen