Anti-CYP2D6 antibodies detected by quantitative radioligand assay and relation to antibodies to liver-specific arginase in patients with autoimmune hepatitis.
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.
Kimura
Masahiro
M
Department of Laboratory Medicine, Osaka University Graduate School of Medicine, D2, 2-2 Yamada-oka, Suita, Osaka 565-0871, Japan.
Tatsumi
Ke-ita
KI
Tada
Hisato
H
Izumi
Yukiko
Y
Kaneko
Akira
A
Kato
Michio
M
Masuzawa
Manabu
M
Ikemoto
Masaki
M
Yabusaki
Yoshiyasu
Y
Hidaka
Yoh
Y
Amino
Nobuyuki
N
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
D001323:Autoantibodies; D015415:Biomarkers; D019389:Cytochrome P-450 CYP2D6; D001119:Arginase