title: Anti-BPIFA1/SPLUNC1: a new autoantibody prevalent in patients with endstage cystic fibrosis.
abstract: BACKGROUND
  Bactericidal/permeability increasing protein fold containing family A (BPIFA) 1, is a secreted protein of the upper airways that shares structural homology with BPI and exhibits comparable antimicrobial capacities. We hypothesized that CF patients have circulating IgG or IgA anti-BPIFA1 autoantibodies, similarly as reported for BPI autoantibodies.
  
  
  METHODS
  We analyzed pre- and post-transplantation sera from 67 endstage lung disease patients who underwent lung transplantation (LTx) because of COPD (n=27), CF (n=25), and ILD (n=15).
  
  
  RESULTS
  Anti-BPIFA1 (48%) and anti-BPI (92%) were elevated in CF patients compared to healthy controls, with anti-BPIFA1 IgG isotype being most prevalent, whereas anti-BPI is of the IgA isotype. Levels of anti-BPI autoantibodies significantly declined post-LTx, whereas anti-BPIFA1 did not. No relation was found between autoantibodies against BPIFA1 and BPI.
  
  
  CONCLUSIONS
  Our results indicate that BPIFA1 is a novel target for autoantibodies in CF. The function of these autoantibodies needed to be investigated in future studies.
authors.affiliation: Laboratory for Translational Immunology, University Medical Centre Utrecht, Utrecht, The Netherlands. Electronic address: k.budding@umcutrecht.nl.
authors.forename: K
authors.initials: K
authors.lastname: Budding
authors.affiliation: Department of Respiratory Medicine, University Medical Centre Utrecht, Utrecht, The Netherlands.
authors.forename: E A
authors.initials: EA
authors.lastname: van de Graaf
authors.affiliation: Laboratory for Translational Immunology, University Medical Centre Utrecht, Utrecht, The Netherlands.
authors.forename: T
authors.initials: T
authors.lastname: Hoefnagel
authors.affiliation: Laboratory for Translational Immunology, University Medical Centre Utrecht, Utrecht, The Netherlands; Department of Rheumatology, University Medical Centre Utrecht, Utrecht, The Netherlands; Department of Dermatology, University Medical Centre Utrecht, Utrecht, The Netherlands.
authors.forename: C E
authors.initials: CE
authors.lastname: Hack
authors.affiliation: Laboratory for Translational Immunology, University Medical Centre Utrecht, Utrecht, The Netherlands.
authors.forename: H G
authors.initials: HG
authors.lastname: Otten
mesh_terms: D000293:Adolescent; D000328:Adult; D001323:Autoantibodies / Q000276:immunology*; D015331:Cohort Studies; D003550:Cystic Fibrosis / Q000453:epidemiology / Q000276:immunology* / Q000601:surgery; D005260:Female; D006023:Glycoproteins / Q000276:immunology*; D018398:Homeodomain Proteins / Q000276:immunology; D006801:Humans; D007070:Immunoglobulin A / Q000276:immunology; D007074:Immunoglobulin G / Q000276:immunology; D016040:Lung Transplantation; D008297:Male; D008875:Middle Aged; D010750:Phosphoproteins / Q000276:immunology*; D029424:Pulmonary Disease, Chronic Obstructive / Q000453:epidemiology / Q000276:immunology* / Q000601:surgery; D012217:Rheumatoid Factor / Q000276:immunology; D016036:Seroepidemiologic Studies; D014157:Transcription Factors / Q000276:immunology; D055815:Young Adult
chemical_list: D001323:Autoantibodies; C485599:BPIFA1 protein, human; C105304:DLX4 protein, human; D006023:Glycoproteins; D018398:Homeodomain Proteins; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D010750:Phosphoproteins; D014157:Transcription Factors; D012217:Rheumatoid Factor
keywords: Autoantibodies; BPI; BPIFA1; Cystic fibrosis; Lung transplantation