title: Detection of autoantibodies to periplakin and envoplakin in paraneoplastic pemphigus but not idiopathic pulmonary fibrosis using full-length recombinant proteins.
abstract: BACKGROUND
  Paraneoplastic pemphigus (PNP) serum preferentially reacts with periplakin and envoplakin, which are plakin family proteins localized to desmosomes and intermediate filaments. Recently, anti-periplakin antibodies were also detected in patients with idiopathic pulmonary fibrosis (IPF). Although previous epitope-mapping studies showed multiple epitopes in each protein, enzyme-linked immunosorbent assays have used several truncated, but not full-length, recombinant proteins.
  
  
  METHODS
  This study aimed to produce full-length biotinylated recombinant proteins of periplakin and envoplakin for detection of autoantibodies by immunoprecipitation and ELISA. Serum from a PNP patient who had been confirmed as carrying anti-periplakin and anti-envoplakin antibodies in our previous study was used as a positive control. Sera from 15 patients with IPF were analyzed for both antibodies by immunoprecipitation and by ELISA.
  
  
  RESULTS
  The PNP serum reacted strongly with the full-length recombinant proteins in immunoprecipitation and ELISA. Longitudinal serum samples from the PNP patient showed a clear decline of autoantibodies to both periplakin and envoplakin. None of the IPF sera showed both autoantibodies.
  
  
  CONCLUSIONS
  We found that the detection of anti-periplakin and anti-envoplakin antibodies using full-length recombinant proteins is useful immunoprecipitation and ELISA.
authors.affiliation: Department of Dermatology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan. Electronic address: ymuro@med.nagoya-u.ac.jp.
authors.forename: Yoshinao
authors.initials: Y
authors.lastname: Muro
authors.affiliation: Department of Dermatology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan.
authors.forename: Kazumitsu
authors.initials: K
authors.lastname: Sugiura
authors.affiliation: Department of Pulmonary Medicine, Ogaki Municipal Hospital, 4-86 Minaminokawa-cho, Ogaki City, Gifu 503-8502, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Shiraki
authors.affiliation: Department of Dermatology, Kurume University School of Medicine and Kurume University Institute of Cutaneous Cell Biology, 67 Asahimachi, Kurume, Fukuoka 830-0011, Japan.
authors.forename: Norito
authors.initials: N
authors.lastname: Ishii
authors.affiliation: Department of Dermatology, Kurume University School of Medicine and Kurume University Institute of Cutaneous Cell Biology, 67 Asahimachi, Kurume, Fukuoka 830-0011, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Hashimoto
authors.affiliation: Department of Dermatology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Akiyama
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001323:Autoantibodies / Q000097:blood* / Q000302:isolation & purification; D001327:Autoimmune Diseases / Q000097:blood; D019921:Biotinylation; D015331:Cohort Studies; D003240:Connective Tissue Diseases / Q000097:blood; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D005260:Female; D006801:Humans; D054990:Idiopathic Pulmonary Fibrosis / Q000097:blood*; D047468:Immunoprecipitation / Q000379:methods*; D008297:Male; D008565:Membrane Proteins / Q000276:immunology* / Q000378:metabolism; D008875:Middle Aged; D010392:Pemphigus / Q000097:blood*; D051179:Plakins / Q000276:immunology* / Q000378:metabolism; D011498:Protein Precursors / Q000276:immunology* / Q000378:metabolism; D011994:Recombinant Proteins / Q000276:immunology / Q000378:metabolism
chemical_list: D001323:Autoantibodies; D008565:Membrane Proteins; C491674:PPL protein, human; D051179:Plakins; D011498:Protein Precursors; D011994:Recombinant Proteins; C100754:envoplakin
keywords: ACTD; Autoantibody; DM; ELISA; Envoplakin; Full-length cDNA; ILD; IPF; IPP; PBS containing 0.05% Tween20; PNP; Paraneoplastic pemphigus; Periplakin; RLU; T-PBS; TnT; autoimmune connective tissue disease; dermatomyositis; idiopathic pulmonary fibrosis; immunoprecipitation; interstitial lung diseases; paraneoplastic pemphigus; relative luminescence unit; transcription and translation