Autoantibodies against glucuronosyltransferases differ between viral hepatitis and autoimmune hepatitis.
OBJECTIVE
Approximately 13% of patients with chronic hepatitis D virus (HDV) infection have liver-kidney microsomal antibodies type 3 (LKM-3) directed against family 1 uridine 5'-diphosphate-glucuronosyl-transferases (UGT-1). The aim of this study was to characterize the prevalence and specificity of LKM-3 by recombinant antigen testing systems.


METHODS
Enzyme-linked immunosorbent assay (ELISA) and Western blot were performed using baculovirus-generated human UGT-1.1 and -1.6 and rabbit UGT-1.6. Sera from patients with HDV (n = 50), autoimmune hepatitis (AIH) type 2 (n = 50), hepatitis B virus (n = 26), hepatitis C virus (HCV) (n = 25), and LKM-1 autoantibody-positive HCV (n = 14) and sera from normal controls (n = 50) and italian patients with HDV and known LKM-3 autoantibodies were studied.


RESULTS
Six percent of patients with HDV from Germany and 8% of patients with type 2 AIH had LKM-3. Sera from italian patients with HDV and patients with AIH type 2 recognized all three recombinant UGT-1. HDV sera from Germany selectively recognized human UGT-1. LKM-3 titers were lower in HDV than in AIH. One patient with AIH had LKM-3 as the only marker of AIH.


CONCLUSIONS
This study indicates a molecular target and titer difference of LKM-3 autoantibodies in German subjects with HDV and AIH. It also suggests a geographic target and titer difference of LKM-3 in HDV. LKM-3 are identified as a rare and previously undescribed independent marker of AIH.
Strassburg
C P
CP
Department of Gastroenterology and Hepatology, Medizinische Hochschule Hannover, Germany.
Obermayer-Straub
P
P
Alex
B
B
Durazzo
M
M
Rizzetto
M
M
Tukey
R H
RH
Manns
M P
MP
D000328:Adult; D000368:Aged; D000818:Animals; D000918:Antibody Specificity; D001323:Autoantibodies / Q000097:blood* / Q000276:immunology; D015153:Blotting, Western; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D014453:Glucuronosyltransferase / Q000276:immunology*; D006521:Hepatitis, Chronic / Q000097:blood / Q000276:immunology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011817:Rabbits; D011994:Recombinant Proteins / Q000276:immunology
D001323:Autoantibodies; D011994:Recombinant Proteins; C060729:anti-liver kidney microsome antibody; D014453:Glucuronosyltransferase