title: Anti-CYP2D6 antibodies detected by quantitative radioligand assay and relation to antibodies to liver-specific arginase in patients with autoimmune hepatitis.
abstract: BACKGROUND
  Antibodies to cytochrome P4502D6 (CYP2D6) were measured and their prevalence compared with that of antibodies to liver-specific arginase in patients with autoimmune hepatitis (AIH).
  
  
  METHODS
  Anti-CYP2D6 antibodies were measured by sensitive radioligand assay and enzyme-linked immunosorbent assay (ELISA), and anti-arginase antibodies were measured by ELISA in 132 patients (definite AIH 11, probable AIH 36, hepatitis C 20, hepatitis B 23, other autoimmune diseases 42) and 50 healthy controls.
  
  
  RESULTS
  CYP2D6 index (radioligand assay) was significantly higher in all groups of patients than those in healthy controls. A higher index than the cut-off value (mean+3 S.D. in healthy controls) was found in 36.4%, 44.4%, 25.0%, 17.4% and 28.6% of patients with definite AIH, probable AIH, hepatitis C, hepatitis B and other autoimmune diseases, respectively. CYP2D6 index was not related to serum IgG, anti-nuclear antibody or AIH scores, and was weakly correlated with anti-arginase antibody activity. When CYP2D6 index and anti-arginase antibodies were combined, 55.3% of AIH patients were positive for either one or both antibodies.
  
  
  CONCLUSIONS
  Anti-CYP2D6 antibodies by radioligand assay were frequently present in patients with AIH. Combined tests for anti-CYP2D6 radioligand assay and anti-arginase antibodies resulted in detection of 55% of AIH patients.
authors.affiliation: Department of Laboratory Medicine, Osaka University Graduate School of Medicine, D2, 2-2 Yamada-oka, Suita, Osaka 565-0871, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Kimura
authors.forename: Ke-ita
authors.initials: KI
authors.lastname: Tatsumi
authors.forename: Hisato
authors.initials: H
authors.lastname: Tada
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Izumi
authors.forename: Akira
authors.initials: A
authors.lastname: Kaneko
authors.forename: Michio
authors.initials: M
authors.lastname: Kato
authors.forename: Manabu
authors.initials: M
authors.lastname: Masuzawa
authors.forename: Masaki
authors.initials: M
authors.lastname: Ikemoto
authors.forename: Yoshiyasu
authors.initials: Y
authors.lastname: Yabusaki
authors.forename: Yoh
authors.initials: Y
authors.lastname: Hidaka
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Amino
mesh_terms: D000918:Antibody Specificity / Q000276:immunology; D001119:Arginase / Q000276:immunology*; D001323:Autoantibodies / Q000097:blood*; D001327:Autoimmune Diseases / Q000175:diagnosis / Q000276:immunology; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D019389:Cytochrome P-450 CYP2D6 / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay / Q000592:standards; D005260:Female; D006509:Hepatitis B / Q000175:diagnosis / Q000276:immunology; D006526:Hepatitis C / Q000175:diagnosis / Q000276:immunology; D019693:Hepatitis, Autoimmune / Q000175:diagnosis / Q000276:immunology*; D006801:Humans; D008099:Liver / Q000201:enzymology*; D008297:Male; D008875:Middle Aged; D011869:Radioligand Assay / Q000592:standards
chemical_list: D001323:Autoantibodies; D015415:Biomarkers; D019389:Cytochrome P-450 CYP2D6; D001119:Arginase