Analysis of hepatitis C virus genome in patients with autoimmune hepatitis type 2.
OBJECTIVE
Hepatitis C virus (HCV) RNA is detectable in a proportion of patients with autoimmune hepatitis type 2, which is characterized by liver-kidney microsomal antibodies (LKM). Therefore, the genotype and sequence of HCV were studied in these patients.


METHODS
Sera from 43 LKM-positive and anti-HCV-positive patients (15 from Germany and 28 from Italy) and 82 LKM-negative and anti-HCV-positive patients (57 from Germany and 25 from Italy) were examined.


RESULTS
Genotyping revealed that the rate of genotype III HCV according to Okamoto's classification in patients with LKM antibody-positive autoimmune hepatitis type 2 was higher than in LKM-negative patients (22.0% vs. 2.4%; P < 0.05). This was because of an increase of genotype III in our patients from Italy. No HCV mutations were found that show a closer sequence homology to cytochrome P450IID6, the major LKM-1 antigen. Deletions in the envelope and nonstructural region 5 were found.


CONCLUSIONS
Because a specific HCV sequence is not associated with the induction of LKM-1 autoantibodies, future research must focus on host factors and possibly additional environmental factors.
Michitaka
K
K
Department of Gastroenterology and Hepatology, Medizinische Hochschule Hannover, Germany.
Durazzo
M
M
Tillmann
H L
HL
Walker
D
D
Philipp
T
T
Manns
M P
MP
D000328:Adult; D000595:Amino Acid Sequence; D001323:Autoantibodies / Q000032:analysis; D001327:Autoimmune Diseases / Q000235:genetics*; D001483:Base Sequence; D005260:Female; D016679:Genome, Viral; D016174:Hepacivirus / Q000235:genetics*; D006505:Hepatitis / Q000235:genetics* / Q000276:immunology; D006801:Humans; D008297:Male; D008875:Middle Aged; D015335:Molecular Probes / Q000235:genetics; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid
D001323:Autoantibodies; D015335:Molecular Probes; C060729:anti-liver kidney microsome antibody