title: IgG anti-apolipoprotein A-1 antibodies in patients with systemic lupus erythematosus are associated with disease activity and corticosteroid therapy: an observational study.
abstract: BACKGROUND
  IgG anti-apolipoprotein A-1 (IgG anti-apoA-1) antibodies are present in patients with systemic lupus erythematosus (SLE) and may link inflammatory disease activity and the increased risk of developing atherosclerosis and cardiovascular disease (CVD) in these patients. We carried out a rigorous analysis of the associations between IgG anti-apoA-1 levels and disease activity, drug therapy, serology, damage, mortality and CVD events in a large British SLE cohort.
  
  
  METHODS
  Serum IgG anti-apoA-1 levels were measured in 100 healthy controls to define a cut-off for positivity. In 499 patients with SLE we obtained the earliest stored serum sample from their disease course and measured IgG anti-apoA-1 level. We then examined associations between IgG anti-apoA-1 positivity in early disease and the development of damage, CVD or death over a mean follow-up period of 12.1 years in these patients. In a separate study, we measured IgG anti-apoA-1 levels in 397 samples taken longitudinally from 49 patients with SLE over a mean period of 89 months of fluctuating disease activity and carried out multi-variable analysis to examine the demographic, serological, disease activity and treatment factors associated with IgG anti-apoA-1 level over time.
  
  
  RESULTS
  In the longitudinal study, IgG anti-apoA-1 levels were significantly higher in patients with persistently active disease, those on high dose corticosteroid and those not taking hydroxychloroquine. Of the 499 subjects who had early disease IgG anti-apoA-1 levels measured, 135 (27%) were positive. However, we found no convincing associations between early IgG anti-apoA-1 positivity and development of damage, mortality or CVD.
  
  
  CONCLUSIONS
  IgG anti-apoA-1 developed early in a quarter of our patients with SLE, but this had no major impact on subsequent clinical outcomes. However, levels of IgG anti-apoA-1 vary over time and are associated with disease activity, treatment with high dose corticosteroid and not taking hydroxychloroquine.
authors.affiliation: Centre for Rheumatology Research, University College London, 5 University Street, London, WC1E 6JF, UK. sara.croca.10@ucl.ac.uk.
authors.forename: Sara
authors.initials: S
authors.lastname: Croca
authors.affiliation: Joint Research Office, UCL/University College London Hospital (UCLH)/Royal Free Hospital, Pond Street, London, NW3 2QG, UK. paul@statsconsultancy.co.uk.
authors.forename: Paul
authors.initials: P
authors.lastname: Bassett
authors.affiliation: Centre for Rheumatology Research, University College London, 5 University Street, London, WC1E 6JF, UK. shrspk@aol.com.
authors.forename: Sharon
authors.initials: S
authors.lastname: Chambers
authors.affiliation: Centre for Rheumatology Research, University College London, 5 University Street, London, WC1E 6JF, UK. maria.davari.10@ucl.ac.uk.
authors.forename: Maria
authors.initials: M
authors.lastname: Davari
authors.affiliation: Centre for Rheumatology Research, University College London, 5 University Street, London, WC1E 6JF, UK. kfalber@gmail.com.
authors.forename: Karim Fouad
authors.initials: KF
authors.lastname: Alber
authors.affiliation: Centre for Rheumatology Research, University College London, 5 University Street, London, WC1E 6JF, UK. oliver.leach.11@ucl.ac.uk.
authors.forename: Oliver
authors.initials: O
authors.lastname: Leach
authors.affiliation: Centre for Rheumatology Research, University College London, 5 University Street, London, WC1E 6JF, UK. y.ioannou@ucl.ac.uk.|Arthritis Research UK Centre for Adolescent Rheumatology (UCL/UCLH/Great Ormond Street Hospital), 5 University Street, London, WC1E 6JF, UK. y.ioannou@ucl.ac.uk.
authors.forename: Yiannis
authors.initials: Y
authors.lastname: Ioannou
authors.affiliation: Centre for Rheumatology Research, University College London, 5 University Street, London, WC1E 6JF, UK. i.giles@ucl.ac.uk.
authors.forename: Ian
authors.initials: I
authors.lastname: Giles
authors.affiliation: Centre for Rheumatology Research, University College London, 5 University Street, London, WC1E 6JF, UK. d.isenberg@ucl.ac.uk.|Arthritis Research UK Centre for Adolescent Rheumatology (UCL/UCLH/Great Ormond Street Hospital), 5 University Street, London, WC1E 6JF, UK. d.isenberg@ucl.ac.uk.
authors.forename: David
authors.initials: D
authors.lastname: Isenberg
authors.affiliation: Centre for Rheumatology Research, University College London, 5 University Street, London, WC1E 6JF, UK. anisur.rahman@ucl.ac.uk.
authors.forename: Anisur
authors.initials: A
authors.lastname: Rahman
mesh_terms: D000328:Adult; D000368:Aged; D016632:Apolipoprotein A-I / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005938:Glucocorticoids / Q000627:therapeutic use*; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood*; D008137:Longitudinal Studies; D008180:Lupus Erythematosus, Systemic / Q000188:drug therapy / Q000276:immunology* / Q000401:mortality; D008297:Male; D008875:Middle Aged; D055815:Young Adult
chemical_list: D016632:Apolipoprotein A-I; D005938:Glucocorticoids; D007074:Immunoglobulin G