title: Serological diagnosis of autoimmune bullous skin diseases: prospective comparison of the BIOCHIP mosaic-based indirect immunofluorescence technique with the conventional multi-step single test strategy.
abstract: BACKGROUND
  Various antigen-specific immunoassays are available for the serological diagnosis of autoimmune bullous diseases. However, a spectrum of different tissue-based and monovalent antigen-specific assays is required to establish the diagnosis. BIOCHIP mosaics consisting of different antigen substrates allow polyvalent immunofluorescence (IF) tests and provide antibody profiles in a single incubation.
  
  
  METHODS
  Slides for indirect IF were prepared, containing BIOCHIPS with the following test substrates in each reaction field: monkey esophagus, primate salt-split skin, antigen dots of tetrameric BP180-NC16A as well as desmoglein 1-, desmoglein 3-, and BP230gC-expressing human HEK293 cells. This BIOCHIP mosaic was probed using a large panel of sera from patients with pemphigus vulgaris (PV, n=65), pemphigus foliaceus (PF, n=50), bullous pemphigoid (BP, n=42), and non-inflammatory skin diseases (n=97) as well as from healthy blood donors (n=100). Furthermore, to evaluate the usability in routine diagnostics, 454 consecutive sera from patients with suspected immunobullous disorders were prospectively analyzed in parallel using a) the IF BIOCHIP mosaic and b) a panel of single antibody assays as commonly used by specialized centers.
  
  
  RESULTS
  Using the BIOCHIP mosaic, sensitivities of the desmoglein 1-, desmoglein 3-, and NC16A-specific substrates were 90%, 98.5% and 100%, respectively. BP230 was recognized by 54% of the BP sera. Specificities ranged from 98.2% to 100% for all substrates. In the prospective study, a high agreement was found between the results obtained by the BIOCHIP mosaic and the single test panel for the diagnosis of BP, PV, PF, and sera without serum autoantibodies (Cohen's κ between 0.88 and 0.97).
  
  
  CONCLUSIONS
  The BIOCHIP mosaic contains sensitive and specific substrates for the indirect IF diagnosis of BP, PF, and PV. Its diagnostic accuracy is comparable with the conventional multi-step approach. The highly standardized and practical BIOCHIP mosaic will facilitate the serological diagnosis of autoimmune blistering diseases.
authors.affiliation: Department of Dermatology, University of Luebeck, Luebeck, Germany.
authors.forename: Nina
authors.initials: N
authors.lastname: van Beek
authors.forename: Kristin
authors.initials: K
authors.lastname: Rentzsch
authors.forename: Christian
authors.initials: C
authors.lastname: Probst
authors.forename: Lars
authors.initials: L
authors.lastname: Komorowski
authors.forename: Michael
authors.initials: M
authors.lastname: Kasperkiewicz
authors.forename: Kai
authors.initials: K
authors.lastname: Fechner
authors.forename: Inga M
authors.initials: IM
authors.lastname: Bloecker
authors.forename: Detlef
authors.initials: D
authors.lastname: Zillikens
authors.forename: Winfried
authors.initials: W
authors.lastname: Stöcker
authors.forename: Enno
authors.initials: E
authors.lastname: Schmidt
mesh_terms: D001327:Autoimmune Diseases / Q000175:diagnosis*; D001483:Base Sequence; D017931:DNA Primers; D019084:Fluorescent Antibody Technique, Indirect / Q000379:methods*; D057809:HEK293 Cells; D006801:Humans; D011446:Prospective Studies; D012872:Skin Diseases, Vesiculobullous / Q000175:diagnosis*
chemical_list: D017931:DNA Primers