Non-organ specific autoantibodies in children with chronic
BACKGROUND/AIMS: Recent studies
in adult patients have established a relationship between hepatitis
C virus infection and the presence of liver-kidney microsomal
autoantibody type 1 (LKM1). Conversely, little is known regarding
the relationship between hepatitis C and autoimmunity in children.
In this study, we investigated non-organ specific autoantibodies in
40 otherwise healthy Italian children with chronic hepatitis
METHODS: All but four patients included in
the study were asymptomatic. Liver histology, obtained in 35,
showed features ranging from minimal to mild chronic hepatitis.
Autoantibodies were investigated by indirect immunofluorescence.
HCV RNA was assayed by the polymerase chain reaction in 34 cases
and viral genotypes were determined.
RESULTS: Antinuclear antibodies were detected
in three (7.5%) cases, one with a homogeneous pattern; smooth
muscle autoantibodies in seven (17.5%) cases, always with V
(vessels only) specificity and LKM1 in four (10%), at titers
ranging from 1:20 and 1:2560. Clinical and virologic features did
not significantly differ between autoantibody positive and negative
cases, although infections with HCV genotypes 1a and 2 were more
frequent in LKM1-positive patients. During observation, the child
with the highest LKM1 titre was unsuccessfully treated with alpha
interferon but responded to steroids. Twelve LKM1 negative children
were also treated with interferon and one developed low LKM1 titers
concomitant with an alanine aminotransferase flare. The sera of the
five LKM1-positive children with investigated by immunoblotting
with a human microsomal fraction and peptide 257-269 of cytochrome
P450IID6. Only the serum of the child with the highest LKM1 titers
CONCLUSIONS: These results show that a
consistent proportion of children with chronic hepatitis C
circulate non-organ specific autoantibodies. The prevalence of LKM1
is greater than in adults and this could raise problems for the
treatment of the disease with interferon. The analysis of LKM1
target antigens might help to identify putative cases of "true"
autoimmune hepatitis with concomitant HCV infection that could
benefit from steroid treatment.