title: Cigarette smoking, antiphospholipid antibodies and vascular events in Systemic Lupus Erythematosus.
abstract: OBJECTIVE
  Smoking can induce autoantibodies in persons who are genetically predisposed to rheumatoid arthritis. We investigated the association between smoking and antiphospholipid antibodies (aPL) in systemic lupus erythematosus (SLE), a question not previously addressed. Further, we explored the relationship between smoking, aPL and vascular events (arterial and venous, VE).
  
  
  METHODS
  In this cross-sectional study, clinical evaluation and questionnaire data were collected from 367 prevalent SLE patients. At the same time, we measured aPL (anticardiolipin (aCL), anti-β2 glycoprotein-1 (aβ2GP1) antibodies IgG/IgM/IgA, and lupus anticoagulant (LA)), and a large set of other SLE-associated autoantibodies for comparison. Association analyses using logistic regression models with smoking, (ever, former and current with never as reference) and antibody status as outcome variable were performed. As a secondary outcome, we investigated the associations between aPL, smoking and VE.
  
  
  RESULTS
  In multivariable-adjusted models ever, and in particular former, cigarette smoking was associated with the most pathogenic aPL; LA, aCL IgG and aβ2GP1 IgG. Other SLE-associated autoantibodies were not associated with smoking. The combination of smoking and aPL was strongly associated with VE. We noted a positive interaction between smoking-LA and smoking-'triple aPL' positivity for previous VE.
  
  
  CONCLUSIONS
  We investigated a large set of commonly occurring autoantibodies in SLE, but only aPL were positively associated with a history of smoking. This association was especially apparent in former smokers. Among ever regular smokers who were aPL positive, we observed a strikingly high frequency of former VE. The underlying mechanisms and temporality between smoking, aPL and VE need further investigations.
authors.affiliation: Rheumatology Unit, Department of Medicine, Karolinska University Hospital, Solna, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Johanna T
authors.initials: JT
authors.lastname: Gustafsson
authors.affiliation: Rheumatology Unit, Department of Medicine, Karolinska University Hospital, Solna, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Iva
authors.initials: I
authors.lastname: Gunnarsson
authors.affiliation: Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Henrik
authors.initials: H
authors.lastname: Källberg
authors.affiliation: Rheumatology Unit, Department of Medicine, Karolinska University Hospital, Solna, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Susanne
authors.initials: S
authors.lastname: Pettersson
authors.affiliation: Rheumatology Unit, Department of Medicine, Karolinska University Hospital, Huddinge, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Agneta
authors.initials: A
authors.lastname: Zickert
authors.affiliation: Rheumatology Unit, Department of Medicine, Karolinska University Hospital, Huddinge, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Anna
authors.initials: A
authors.lastname: Vikerfors
authors.affiliation: Rheumatology Unit, Department of Medicine, Karolinska University Hospital, Solna, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Sonia
authors.initials: S
authors.lastname: Möller
authors.affiliation: Department of Immunology, Genetics and Pathology, Rudbeck Laboratory C5, Uppsala University, Uppsala, Sweden.
authors.forename: Johan
authors.initials: J
authors.lastname: Rönnelid
authors.affiliation: Unit of Clinical Immunology, Department of Clinical Immunology and Transfusion Medicine, Karolinska University Hospital, Solna, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Kerstin
authors.initials: K
authors.lastname: Elvin
authors.affiliation: Rheumatology Unit, Department of Medicine, Karolinska University Hospital, Solna, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Elisabet
authors.initials: E
authors.lastname: Svenungsson
mesh_terms: D000328:Adult; D017152:Antibodies, Antiphospholipid / Q000032:analysis*; D002318:Cardiovascular Diseases / Q000453:epidemiology; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D016015:Logistic Models; D008180:Lupus Erythematosus, Systemic / Q000453:epidemiology* / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D012907:Smoking / Q000453:epidemiology* / Q000276:immunology
chemical_list: D017152:Antibodies, Antiphospholipid
keywords: Antiphospholipid Antibodies; Cardiovascular Disease; Epidemiology; Smoking; Systemic Lupus Erythematosus