title: Anti-programmed cell death-1 antibody as a new serological marker for type 1 autoimmune hepatitis.
abstract: OBJECTIVE
  Recently, the association of the dysfunction of programmed cell death (PD)-1 expressed on activated lymphocytes with the pathogenesis of autoimmune hepatitis (AIH) has been speculated. This study aimed to investigate the association of serum anti-PD-1 antibodies with clinical characteristics of type 1 AIH.
  
  
  METHODS
  Serum samples before the initiation of prednisolone treatment were obtained from 52 type 1 AIH patients, 24 patients with drug-induced liver injury (DILI), 30 patients with acute viral hepatitis (AVH), 11 patients with primary sclerosing cholangitis (PSC), and 62 healthy volunteers. Titers of serum anti-PD-1 antibodies were measured by indirect enzyme-linked immunosorbent assay. The cutoff level was represented by a mean absorbance + 2 standard deviations in healthy volunteers.
  
  
  RESULTS
  Prevalence of serum anti-PD-1 antibodies was 63% in type 1 AIH patients, 8% in DILI patients, 13% in AVH patients, 18% in PSC patients, and 3% in healthy volunteers. In type 1 AIH patients, titers of serum anti-PD-1 antibodies were correlated with serum levels of bilirubin (r = 0.31, P = 0.030) and alanine aminotransferase (r = 0.31, P = 0.027) but not serum immunoglobulin G levels. Positivity for serum anti-PD-1 antibodies was associated with the later normalization of serum alanine aminotransferase levels after the initiation of prednisolone and the disease relapse.
  
  
  CONCLUSIONS
  Serum anti-PD-1 antibodies would be useful for the discrimination of type 1 AIH from DILI, AVH, and PSC as an auxiliary diagnostic marker. Furthermore, anti-PD-1 antibodies may be associated with clinical characteristics of type 1 AIH.
authors.affiliation: Department of Gastroenterology & Hepatology, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama, Japan.
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Matsumoto
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Miyake
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Matsushita
authors.forename: Atsuyuki
authors.initials: A
authors.lastname: Ohnishi
authors.forename: Fusao
authors.initials: F
authors.lastname: Ikeda
authors.forename: Hidenori
authors.initials: H
authors.lastname: Shiraha
authors.forename: Akinobu
authors.initials: A
authors.lastname: Takaki
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Nouso
authors.forename: Kazuhide
authors.initials: K
authors.lastname: Yamamoto
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001323:Autoantibodies / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D003937:Diagnosis, Differential; D004797:Enzyme-Linked Immunosorbent Assay; D019693:Hepatitis, Autoimmune / Q000145:classification / Q000175:diagnosis*; D006801:Humans; D008214:Lymphocytes / Q000276:immunology; D008297:Male; D008875:Middle Aged; D061026:Programmed Cell Death 1 Receptor / Q000276:immunology* / Q000502:physiology; D055815:Young Adult
chemical_list: D001323:Autoantibodies; D015415:Biomarkers; D061026:Programmed Cell Death 1 Receptor
keywords: acute viral hepatitis; autoimmune hepatitis; drug-induced liver injury; primary sclerosing cholangitis; programmed cell death-1