Histological and virological features and follow-up of hepatitis C virus carriers with normal aminotransferase levels: the Italian prospective study of the asymptomatic C carriers (ISACC).

Background/aims: To evaluate demographic characteristics, liver histology and virological features of hepatitis C virus (HCV) carriers with normal alanine transaminase (ALT) levels.
Methods: A nationwide prospective study was started in 1997. Four Italian centres have participated in this study.
Results: Eight hundred and eighty subjects entered the study. One hundred and eighty-nine (21.5%) were excluded during the follow-up because of ALT increase. Among the 691 patients with persistent ALT normality, 72% were females. An overall prevalence of genotype 2 was found (52%). Normal liver was found in 17% of the patients; 34% had minimal chronic hepatitis, 44% mild hepatitis, 4% moderate to severe hepatitis, and 1% had cirrhosis. Clinical and virological features did not differ between subjects with ALT flares and those with persistently normal ALT. Baseline ALT levels have no effects on liver histology and clinical outcome.
Conclusions: Many HCV carriers have significant chronic liver damage, although in the majority of them liver lesions are minimal or mild. Up to 60% of HCV carriers in Italy harbour non-1 HCV types. Current definition of HCV carriers with persistently normal ALT levels, based upon three normal ALT values over a 6-month period, is not adequate to discriminate between carriers with persistent ALT normality and those with transient biochemical remission. Longer follow-ups are needed.