title: IgA autoantibodies in the pemphigoids and linear IgA bullous dermatosis.
abstract: BACKGROUND
  Patients with bullous pemphigoid (BP), mucous membrane pemphigoid (MMP) and pemphigoid gestationis (PG) have IgG antibodies against BP180 and BP230, components of the hemidesmosomes. Patients with linear IgA bullous dermatosis (LABD) have IgA autoantibodies against a 97/120-kDa protein which is highly homologous to a shedded fragment of the BP180-ectodomain.
  
  
  OBJECTIVE
  The aim of our study was to determine the incidence of IgA autoantibodies directed against BP180/BP230 in the pemphigoids and LABD and to determine the antigenic regions that are targeted by IgA autoantibodies.
  
  
  METHODS
  Utilizing baculovirus-expressed recombinant BP180 and BP230 proteins, we performed immunoblot analyses for IgA reactivity of sera from patients with BP (n = 30), MMP (n = 10), PG (n = 6), LABD (n = 6) and from control patients with non-related pruritic dermatoses (n = 8).
  
  
  RESULTS
  IgA reactivity against BP180 and/or BP230 was detected in 19/30 of the BP, in 7/10 of the MMP, in 6/6 of the LABD and in 3/6 of the PG sera, respectively, but not in the control group. In all subgroups, the major antigenic site recognized by IgA antibodies was located within the NH(2)-terminus of the BP180-ectodomain, but only a minority of the sera showed also IgA reactivity against the BP180-NC16a-domain. IgA reactivity against the central domain of BP180 was more frequently seen than against its COOH-terminus. IgA against the COOH- and NH(2)-terminus of BP230, respectively, was detected in 6/30 of the BP, 1/10 of the MMP, 1/6 of the LABD and 0/8 control sera.
  
  
  CONCLUSIONS
  IgA reactivity against BP180 and/or BP230 is a common finding in the pemphigoids.
authors.affiliation: Philipps University, Department of Dermatology and Allergology, Marburg, Germany. b.horvath@derm.umcg.nl
authors.forename: Barbara
authors.initials: B
authors.lastname: Horváth
authors.forename: Andrea
authors.initials: A
authors.lastname: Niedermeier
authors.forename: Eva
authors.initials: E
authors.lastname: Podstawa
authors.forename: Ralf
authors.initials: R
authors.lastname: Müller
authors.forename: Nicolas
authors.initials: N
authors.lastname: Hunzelmann
authors.forename: Sarolta
authors.initials: S
authors.lastname: Kárpáti
authors.forename: Michael
authors.initials: M
authors.lastname: Hertl
mesh_terms: D000328:Adult; D001323:Autoantibodies / Q000097:blood*; D001324:Autoantigens / Q000737:chemistry; D002352:Carrier Proteins / Q000737:chemistry / Q000276:immunology; D016022:Case-Control Studies; D003598:Cytoskeletal Proteins / Q000737:chemistry / Q000276:immunology; D000071821:Dystonin; D005260:Female; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood*; D009419:Nerve Tissue Proteins / Q000737:chemistry / Q000276:immunology; D024041:Non-Fibrillar Collagens / Q000737:chemistry; D006559:Pemphigoid Gestationis / Q000276:immunology*; D010390:Pemphigoid, Benign Mucous Membrane / Q000276:immunology*; D010391:Pemphigoid, Bullous / Q000276:immunology*; D011247:Pregnancy; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000737:chemistry / Q000276:immunology; D000097805:Collagen Type XVII
chemical_list: D001323:Autoantibodies; D001324:Autoantigens; D002352:Carrier Proteins; D003598:Cytoskeletal Proteins; D000071821:Dystonin; D007070:Immunoglobulin A; D009419:Nerve Tissue Proteins; D024041:Non-Fibrillar Collagens; D011994:Recombinant Proteins; D000097805:Collagen Type XVII; C486268:DST protein, human