Retrospective analysis of acute HBV infections occurred in 1978-79 and 1994-95 in North-East Italy: increasing prevalence of BCP/pre-core mutants in sub-genotype D3.

BACKGROUND: At the end of the 1970s, in Italy more than 2% of the general population was HBsAg carrier. In the late '70s and late '80s, two remarkable events might have impacted on HBV strains transmitted in North-East Italy: (a) the increased HBV incidence due to parenteral drugs between 1978 and 1982; (b) the preventive anti-HIV educational campaign, started locally in 1985. METHODS: To address if those events impacted on circulating HBV variants, acute cases occurred in North-East Italy in 1978-79 (n = 50) and 1994-95 (n = 30) were retrospectively analysed. HBV sequences obtained from serum samples were subjected to phylogenetic analysis and search for BCP/pre-core and S mutations. RESULTS: HBV-D was the most prevalent genotype in both 1978-79 (43/50, 86%) and 1994-95 (24/30, 80.0%), with HBV-A in all but one remaining cases. Among HBV-D cases, sub-genotype HBV-D3 was the most prevalent (25/29, 86.2% in 1978-79; 13/16, 81.2% in 1994-95), with HBV-D1 and HBV-D2 in the remaining cases. All HBV-A cases were sub-genotype A2. Single and multiple BCP/pre-core mutations, responsible for HBeAg(-) hepatitis, were detected in 6/50 (12%) cases in 1978/79 vs. 12/30 (40.0%) in 1994/95 (p = 0.006). They were found exclusively in HBV-D; in the most abundant sub-genotype, HBV-D3, they were detected in 2/25 (8%) cases in 1978-79 vs. 6/13 (46%) in 1994-95 (p = 0.011). No vaccine escape S mutations were observed. The IDU risk factor was significantly more frequent in 1994-95 (8/30, 26.7%) than in 1978-79 (4/50, 8%) (p = 0.048). CONCLUSIONS: The above mentioned epidemiological and public health events did not affect the proportion of genotypes and sub-genotypes that remained unchanged over 16 years. In contrast, the proportion of BCP/pre-core mutants increased more than three-fold, mostly in HBV-D3, a sub-genotype highly circulating in IDUs; drug abuse likely contributed to the spread of these mutants. The findings contribute to explain a previously described major change in HBV epidemiology in Italy: the proportion of HBeAg(-) cases in the carrier cohort changed from low in late 1970s, to high at the beginning of the 2000s. In addition to other recognized factors, the increased circulation of BCP/pre-core mutants likely represents a further factor that contributed to this change.

HBV pre-core mutant in genotype-D infected children is selected during HBeAg/anti-HBe seroconversion and leads to HBeAg negative chronic hepatitis B in adulthood.

Selection of HBeAg defective HBV mutants (mt) during childhood might influence infection outcome in adults. Aim of this study was to correlate the dynamics of pre-core HBV mutant (pre-C mt) selection with virological/clinical outcomes in children followed-up until adulthood. Eighty subjects (50-M/30-F), 70 HBeAg-positive (87.5%), and 10 (12.5%) HBeAg-negative/anti-HBe-positive at the admission, mostly genotype D infected (91.2%), with median age of 6.5 (range: 0.2-17) years, were followed-up for 14.3 years (range: 1.1-24.5); 46 (57.5%) received IFN treatment. HBV-DNA and q-HBsAg were tested by commercial assays, Pre-Core 1896 mt by direct-sequence, oligo-hybridization-assay, and allele-specific-PCR (sensitivity: 30%, 10%, and 0.1% of total viremia). HBeAg/anti-HBe seroconversion (SC) occurred in 55/70 (78.6%) children. After SC, 8 (14.6%) developed HBeAg-negative chronic hepatitis (CHB), 41 (74.5%) remain with HBeAg-negative chronic infection, and 6 (10.9%) lost HBsAg. Baseline HBV-DNA and HBsAg were lower in SC than in no-SC children (median: 7.35 vs 8.95 Log IU/mL, P = 0.005, and 4.72 vs 5.04 Log IU/mL, P = 0.015). The prevalence of pre-C mt increased rapidly (10-40%) around SC. Eventually, pre-C mt was detected in 100% of CHB, in 33% of chronic infections without disease, and in 16% of subjects who cleared HBsAg (P < 0.001). HBV-DNA levels remained slightly higher in carriers of HBeAg negative infection with dominant/mixed pre-C mt populations, than in those with dominant pre-C wt (mean Log IU/mL: 3.83 and 3.42 vs 2.67, P = 0.007). In conclusion, pre-C-mt is selected during HBeAg/anti-HBe SC in children with poor control of HBV replication, leading to HBeAg-negative chronic-active-hepatitis during adulthood.

Hepatitis B virus genotype change in children is closely related to HBeAg/anti-HBe seroconversion.

BACKGROUND AND OBJECTIVES: Genotype changes have been observed during long-term follow-up in adults with chronic hepatitis B virus (HBV) infection. The aim of this study was to assess the frequency and distribution of HBV genotype shifts in treated and untreated European children during the different phases of chronic hepatitis B. METHODS: The initial population consisted of 85 HBeAg-positive children who were sequentially investigated for HBV genotypes for a mean period of 7.1 years. During the survey, 65 patients seroconverted to anti-HBe and 24 received antiviral treatment. Genotyping was done by restriction fragment length polymorphism. RESULTS: Genotypes at enrollment were distributed as follows: D (n = 67), A (n = 11), B (n = 4), and C and mixed (n = 3). A genotype change was observed in 16 (19%) participants at last visit, of whom 1 of 20 (5%) remained persistently HBeAg positive and 15 of 65 (23%) children had seroconverted to anti-HBe (P < 0.001). The genotype shift was D to A or B in 9 individuals, A to D in 5, and A to B in 1. Genotype changes were more frequent in untreated than in treated subjects; however, the difference was not statistically significant. CONCLUSIONS: The results of this study suggest that genotype change is a relatively frequent event in children with chronic hepatitis B after anti-HBe seroconversion and independent of treatment. The reasons why only some patients will experience this event remain to be clarified.

High sustained virologic response rates in children with chronic hepatitis C receiving peginterferon alfa-2b plus ribavirin.

BACKGROUND & AIMS: Pegylated interferon (PEG-IFN) alfa-2b plus ribavirin (RBV) is the standard of care for adults with chronic hepatitis C but was not approved for the treatment of children at the time of this study. The aim of this study was to evaluate the efficacy and safety of PEG-IFN alfa-2b plus RBV in children. METHODS: Children and adolescents ages 3-17 years were treated with PEG-IFN alfa-2b (60microg/m(2)/week) plus RBV (15mg/kg/day). The duration of therapy was 24 weeks for genotype (G) 2 and G3 patients with low viral load (<600,000IU/ml) and 48 weeks for G1, G4, and G3 with high viral load (>or=600,000IU/ml). The primary end point was sustained virologic response (SVR), defined as undetectable hepatitis C virus (HCV) RNA 24 weeks after completion of therapy. RESULTS: SVR was attained by 70 (65%) children. Genotype was the main predictor of response: G1, 53%; G2/3, 93%; G4, 80%. SVRs were similar in younger and older children. Baseline viral load was the main predictor of response in the G1 cohort. No new safety signals were identified, and adverse events (AEs) were generally mild or moderate in severity. Dose was modified because of AEs in 25% of children; 1 child discontinued because of an AE (thrombocytopenia). No serious AEs related to study drugs were reported. CONCLUSION: Therapy with PEG-IFN alfa-2b plus RBV in children and adolescents with chronic hepatitis C offers favorable efficacy, reduced injection frequency, and an acceptable safety profile.

An updated follow-up of chronic hepatitis C after three decades of observation in pediatric patients cured of malignancy.

BACKGROUND: The aim of the study was to evaluate the clinical characteristics and the long-term outcome of chronic hepatitis C in a cohort of Caucasian children cured of pediatric malignancy. PROCEDURE: The study population included 83 consecutive patients, referred to our Center with a diagnosis of leukemia/lymphoma (50) or solid tumors (33) between 1977 and 1989 and infected with hepatitis C virus (HCV) during chemotherapy. RESULTS: At enrollment 77 subjects were HCV-RNA positive. After a median follow-up of 21 years (range 13-36), a sustained virological response (SVR) was obtained in 3 of 29 patients (10%) treated with interferon (IFN), in 1 of 3 patients (33%) treated with IFN and ribavirin, and in 5 of 11 patients (42%) treated with pegylated-IFN and ribavirin (P = 0.03). Forty-two patients remained untreated and only one (2.5%) cleared viremia. Four of 77 patients (5%) developed cirrhosis while other 4 patients died of causes not related to liver. At last follow-up, 72% of HCV-RNA positive patients had abnormal ALT. CONCLUSIONS: In patients cured of pediatric malignancy chronic hepatitis C tends to run an indolent course during childhood and adolescence but more than 70% of treated and more than 80% of untreated cases children maintained HCV viremia. Moreover, after 2-3 decades of observation, 60% of HCV-RNA positive patients had abnormal ALT and 5% had developed cirrhosis. Among treated patients, IFN or pegylated-IFN and ribavirin obtained the higher rate of HCV-RNA clearance.

Long-term course of chronic hepatitis C in children: from viral clearance to end-stage liver disease.

BACKGROUND & AIMS: The natural course of chronic hepatitis C (CHC) in children is not well understood. The aim of this study was to assess the long-term course of CHC in a large sample of otherwise healthy children. METHODS: From 1990 to 2005, 504 consecutive antihepatitis C virus (HCV)-positive children were enrolled at 12 centers of a national observatory and were followed up retrospectively/prospectively. RESULTS: Putative exposure was perinatal in 283 (56.2%) cases, parenteral in 158 (31.3%), and unknown in 63 (12.5%). At baseline, 477 (94.6%) cases were HCV RNA seropositive, 118 (24.7%) of which were treated with standard interferon alpha. Ten years after putative exposure, the outcome in 359 HCV RNA-positive, untreated patients was (1) undetectable viremia in 27 (7.5%) (by Cox regression analysis, spontaneous viral clearance was independently predicted by genotype 3 [hazard ratio 6.44; 95% confidence interval: 2.7-15.5]) and (2) persistent viremia in 332 (92%) cases. Six of these 332 cases (1.8%) progressed to decompensated cirrhosis (mean age, 9.6 years). This latter group included 5 Italian children perinatally infected with genotype 1a (4 of the mothers were drug users). Thirty-three (27.9%) treated patients achieved a sustained virologic response. CONCLUSIONS: Over the course of a decade, few children with chronic HCV infection cleared viremia spontaneously, and those who did were more likely to have genotype 3. Persistent viral replication led to end-stage liver disease in a small subgroup characterized by perinatal exposure, maternal drug use, and infection with HCV genotype 1a. Children with such features should be considered for early treatment.

[Chronic hepatitis C in children: natural history and prognosis]. / Attuali conoscenze sul decorso e sulla prognosi dell'epatite cronica da virus C nei bambini.

Chronic hepatitis C has been described as a mild disease in children, but viremia persists up to adult life in more than 80% of cases, fibrosis is slowly progressing throughout adolescence and youth, and early appearance of end stage liver disease has been recently documented. These findings, and the efficacy of current therapeutic strategies in adults, support the potential benefits of early treatment in children with chronic hepatitis C.

Reversal of liver cirrhosis: a desirable clinical outcome and its pathogenic background.

Cirrhosis is the final stage of chronic liver damage of various etiologies. It used to be considered an irreversible lesion, but enormous advances in our understanding of hepatic cellular and molecular biology in the past 2 decades have challenged this view. There is now substantial evidence that cirrhosis can be a reversible process. This concept is supported by an increasing number of clinical reports showing the disappearance of cirrhotic lesions from liver biopsies taken from patients cured of their liver disease. The reversal of cirrhosis usually occurs in patients with short-lived liver disease, after the successful treatment of the underlying liver damage. Recently, however, we observed the spontaneous reversal of cirrhosis after the loss of hepatitis B viremia in 2 men, 21 and 28 years old, who had developed cirrhosis as young children. Several questions and controversial issues concerning the definition of advanced cirrhosis, the limitations of liver biopsy (eg, sampling, interpretation error), and the applicability of noninvasive methods to the assessment of fibrosis, are being addressed. Future prospects include the possibility of antifibrotic therapy to prevent fibrosis or favor its degradation.

Evidence for the presence of autochthonous (locally acquired) cases of acute hepatitis E virus infections in Italy since the 80s.

BACKGROUND: Autochthonous (locally acquired) cases of acute hepatitis E virus have been recently reported in several developed countries. AIM: To evidence cases, if any, and characteristics of acute hepatitis E virus infections in North-East of Italy several years ago. METHODS: In 2014, stored sera of 165 nonA-nonB acute hepatitis referred to the hospital of Padua during the period 1978-1991 were tested for hepatitis C virus antibodies by EIA III and for anti-hepatitis E virus IgM by Wantai HEV IgM ELISA. Anti-hepatitis E virus IgM positive sera were tested by Real Star HEV RT-PCR kit (Altona Diagnostics, Hamburg, Germany). RESULTS: Ninety-six (58.1%) sera resulted anti-HCV positive, and thus classified as acute C hepatitis. None of these subjects was anti-HEV IgM positive. Out of the 69 anti-HCV negative cases, 4 (5.8%) resulted anti-HEV IgM positive (one case hepatitis E virus-RNA positive), with an increasing trend from 2.8% during the years 1978-1984 to 9.1% during the years 1985-1991. All cases occurred in Italian patients with no travel abroad history. CONCLUSIONS: There is evidence for the presence of autochthonous cases of acute hepatitis E virus infections in Italy since 80s.

Chronic hepatitis C virus infection in childhood: clinical patterns and evolution in 224 white children.

The characteristics and evolution of hepatitis C virus (HCV) infection were retrospectively investigated in a study of 224 HCV RNA-seropositive white children who were consecutively recruited at 7 European centers in 1980-1998. At presentation, all patients were positive for antibodies to hepatitis C virus, 87% were asymptomatic, and 48% had alanine aminotransferase (ALT) levels that were < or =2 times the upper limit of the range considered to be normal. Of 200 children followed for 1-17.5 years (mean follow-up +/- standard deviation [SD], 6.2+/-4.7 years), only 12 (6%) achieved sustained viremia clearance and normalization of the ALT level. In 92 revised liver biopsy specimen analyses, the mean fibrosis score (+/-SD) was 1.5+/-1.3 for children <15 years of age and 2.3+/-1.2 for children > or =15 years of age (range, 0-6 years; P<.01). Pediatric HCV infection is usually mild, but few patients, especially those who are perinatally infected, clear viremia in the medium-term follow-up. Conversely, the higher rates of fibrosis observed in older patients suggest the possibility of an insidious progression of HCV-associated liver disease.

Hepatitis C virus infection in children coinfected with HIV: epidemiology and management.

Mothers with hepatitis C virus (HCV) and HIV coinfection are the major source of HCV/HIV coinfection in infancy and childhood. There is no known intervention capable of interrupting HCV spread from mother to child, while the majority of infant HIV infections occurring in the developed world can be prevented by antiretroviral prophylaxis in the mother and child, elective caesarean section, and formula-feeding. In the era preceding treatment of HIV infection with highly active antiretroviral therapy, HCV coinfection was of little concern because the short-term survival of patients with HIV infection prevented the slowly developing consequences of chronic hepatitis C. As the life expectancy of patients with HIV infection increased with therapy, HCV has emerged as a significant pathogen. Several lines of evidence in adult patients suggest that liver disease may be more severe in patients coinfected with HIV and that progression of HIV disease may be accelerated by HCV coinfection. Whether coinfected children may share these clinical patterns remains a matter of speculation. Chronic hepatitis C in otherwise healthy children is usually a mild disease; liver damage may be sustained and fibrosis may increase over the years, suggesting slow progression of the disease. Interferon-alpha has been the only drug used in the past decade to treat hepatitis C in children and adolescents, with average response rates of 20%. Preliminary results of treatment with interferon-alpha and ribavirin suggest that the efficacy would be greater with combined therapy. These treatment protocols have not yet been applied to children coinfected with HIV, but the increasing number of long-term survivors will probably prompt further investigation in the near future. At present, treating HIV disease and monitoring HCV infection and hepatotoxicity induced by antiretroviral drugs seem to be the more reasonable approach to HCV/HIV coinfection in childhood.

Historical study of acute hepatitis B in subjects with or without hepatitis C infection.

BACKGROUND: The epidemiological pattern of hepatitis B virus infection in Italy has greatly changed over the past decades. The aim of the study was to evaluate during time the epidemiological features of acute hepatitis B cases referred to an Infectious Disease Unit in North-East of Italy between 1978 and 1995. PATIENTS AND METHODS: Stored sera of 183 cases were tested for HBV markers, HBV genotypes, anti-Delta and anti-HCV. RESULTS: Anti-HBcIgM was positive in all cases. Mean age increased from 30.2 years in 1978 to 37.5 in 1995 (P<0.01). Significant increase was observed in proportion of cases reporting intravenous drug use from 11.5% to 29.6% (P<0.03). Chronicity rate was as low as 1.1%. Mean days of hospitalization significantly decreased. HBV genotype determination showed that majority of cases was infected by genotype D, but its prevalence decreased from 88.2% in 1978 to 75.0% in 1995. Delta coinfection was present in 8.2%. The prevalence of HCV in patients with acute HBV was 35.0%; it fluctuated from 26.2% to 44.2%, mostly related (53.1%) to intravenous drug use. Dual infection did not lead to a more severe course of disease. CONCLUSIONS: From this retrospective study, remarkable fluctuations in the prevalence of dual HBV-HCV infection before the implementation of HBV vaccination were observed. Presence of anti-HCV did not affect the course of acute HBV.

Viral hepatitis: Treating hepatitis C in children: an open horizon.

Most children with chronic hepatitis C have minimal liver disease before adulthood, but could be at risk of progression to cirrhosis and hepatocellular carcinoma because of persistent virus replication. The results of the first controlled trial with PEG-IFN-α2a plus ribavirin are a step towards an appropriate treatment for these children.

Management of chronic hepatitis C in childhood: the impact of therapy in the clinical practice during the first 2 decades.

BACKGROUND AND AIM: Treatment of chronic hepatitis C in children is controversial and its role in the clinical practice is unknown. We retrospectively investigated the impact of treatment in a large cohort of children with chronic hepatitis C over the past 20 years. METHODS: 376 hepatitis C virus RNA positive children were recruited consecutively in five Italian centres since 1990 and followed for 1-17 years. RESULTS: 86 (23%) subjects were treated: 73 with recombinant interferon alone and 13 with pegylated-interferon and ribavirin. Sustained clearance of hepatitis C virus RNA was observed in 25% of the former, in 92% of the latter and in 9% of untreated cases (p < 0.001). Loss of viraemia was recorded in all children with genotype 2-3 and in 6 of 7 with hepatitis C virus genotype 1 treated with combination therapy. At last evaluation 45% of patients were young adults and 15% had cleared viraemia. Overall, 152 (40%) were putative candidates to therapy. CONCLUSIONS: Few Italian children with chronic hepatitis C have been treated in the past 20 years. The poor propensity to spontaneous clearance of viraemia and the efficacy of combination therapy should encourage to consider treatment in attempt to shorten the duration of viral replication.

Natural history of chronic hepatitis B: special emphasis on disease progression and prognostic factors.

The natural history of chronic hepatitis B virus (HBV) infection and disease is complex and highly variable. We review the natural history of chronic hepatitis B with emphasis on the rates of disease progression and factors influencing the course of the liver disease. Chronic hepatitis B is characterized by an early replicative phase (HBeAg positive chronic hepatitis) and a late low or non-replication phase with HBeAg seroconversion and liver disease remission (inactive carrier state). Most patients become inactive carriers after spontaneous HBeAg seroconversion with good prognosis, but progression to HBeAg negative chronic hepatitis due to HBV variants not expressing HBeAg occurs at a rate of 1-3 per 100 person years following HBeAg seroconversion. The incidence of cirrhosis appears to be about 2-fold higher in HBeAg negative compared to HBeAg positive chronic hepatitis. In the cirrhotic patient the 5-year cumulative risk of developing hepatocellular carcinoma is 17% in East Asia and 10% in the Western Europe and the United States and the 5-year liver related death rate is 15% in Europe and 14% in East Asia. There is a growing understanding of viral, host and environmental factors influencing disease progression, which ultimately could improve the management of chronic hepatitis B.

Epidemiological profile of 806 Italian children with hepatitis C virus infection over a 15-year period.

BACKGROUND/AIMS: To evaluate the epidemiological profile of Italian children with hepatitis C virus (HCV) infection over a 15-year period. METHODS: Fifteen tertiary care centers, belonging to a national Observatory established in 1998, retrospectively/prospectively recruited 806 consecutive HCV-infected, otherwise healthy, children seen from 1990 to 2004. RESULTS: Seven hundred and sixty four were Italian and 42 from foreign countries. Newly-diagnosed cases declined from 332 in 1995-1999 to 196 in 2000-2004, while the proportion of foreign children rose from 3% to 13%. Transfusion-transmitted infection disappeared after 1992. Maternal infection (with drug abuse in 63% of cases in the North) has become the most important mode of HCV diffusion throughout Italy and the exclusive source for all children infected in 2000-2004. The prevalence of HCV genotypes 3 and 4 increased and that of genotype 1b decreased significantly (p<0.02). Male/female ratio was significantly (p<0.001) lower among vertically infected (0.6) than in transfused children (1.3). CONCLUSIONS: The number of children with newly-diagnosed HCV infection is declining in Italy and most post-transfusion cases are now young adults. Thus foreign children could significantly contribute to the reservoir of pediatric infection in years to come. New infections result from maternal transmission and seem to privilege females and genotypes 3 and 4.

Liver steatosis in children with chronic hepatitis C.

OBJECTIVES: Steatosis is common in adults with chronic hepatitis C, and is involved in the progression of fibrosis. Because little is known about steatosis in pediatric hepatitis C, the aims of this study were to determine the prevalence and severity of steatosis in a pediatric population with chronic hepatitis C, and to evaluate its correlation with clinical parameters. METHODS: Liver biopsies were obtained from 66 consecutive Italian and Spanish children with chronic hepatitis C (87.6% genotype 1). Grade and stage were assessed according to Ishak's system. Steatosis was scored as absent, minimal (less than 5% of steatosic hepatocytes), mild (>5%, 33%, 66%); moderate and severe scores were combined for statistical purposes. The BMI-for-age percentile (BMI%) was calculated in all cases at the time of liver biopsy. Cholesterol and triglyceride serum levels were available in 55 cases. RESULTS: The prevalence of steatosis was 27% (18/66 cases, 16/18 with genotype 1), and it was higher in Italian than in Spanish patients (10/21 vs.7/45, P= 0.01). BMI% correlated significantly with both the presence of steatosis (P= 0.002) and its severity (P= 0.000). Steatosis also correlated with serum triglyceride levels (P= 0.04). CONCLUSION: Steatosis is associated with BMI in children with chronic hepatitis C due mainly to genotype 1, and with no confounding hepatotoxic factors (alcohol or drugs). This may reflect its metabolic rather than viral origin and raise new issues in the management of children with hepatitis C.

Chronic hepatitis B in children after e antigen seroclearance: final report of a 29-year longitudinal study.

Chronic hepatitis B is usually a benign disease in Caucasian children; however, the long-term prognosis remains unsettled. This report describes the results of a 29-year longitudinal study including 99 white children with chronic hepatitis B, mainly acquired horizontally: 91 were hepatitis B e antigen (HBeAg) positive (4 had cirrhosis), and 8 were HBeAg negative at presentation. Of the 91 HBeAg-positive children, 89 underwent HBeAg seroconversion after a mean period of 5.2 +/- 4.0 years and were included in the study. Of the 85 children without cirrhosis, one had HBeAg-negative hepatitis and the other 84 became inactive carriers. During a mean follow-up of 14.5 +/- 6.1 years after HBeAg seroclearance, 4 carriers experienced reactivation, and 3 of them had HBeAg-negative hepatitis at the last follow-up. Of the 8 initially HBeAg-negative children, 2 had HBeAg-negative hepatitis, and 6 were inactive carriers. Of the 4 children with cirrhosis, 2 had hepatocellular carcinoma (HCC) and remained alive and 2 lost the histological features of cirrhosis in adulthood. Two patients with HBeAg-negative hepatitis and 1 with cirrhosis had experienced drug abuse. At the end of follow-up, 15 of the 89 initially HBeAg-positive patients and 2 of 8 initially HBeAg-negative children had cleared hepatitis B surface antigen. In conclusion, the overall prognosis for chronic hepatitis B in horizontally infected Caucasian children is favorable; however, some patients progress to HCC and HBeAg-negative hepatitis. Long-term monitoring is important, as is counseling on cofactors of liver damage, such as alcohol and drug abuse.

Clinical features and progression of perinatally acquired hepatitis C virus infection.

The purpose of this prospective-retrospective study was to provide information about the clinical features and progression of hepatitis C virus (HCV) infection transmitted perinatally. Seventy children born to HCV infected woman were enrolled consecutively in five European centers between 1990 and 1999, provided they had HCV RNA in the serum during the first year of life and/or were still anti-HCV positive at 18 months. Sixty-two infants were followed up to 24 months of age or more (range, 24 months-11 years; average, 4.8 +/- 2.3 years). A wide range of ALT elevation was observed in 93% of the infants in the first year of life. During the follow-up, a sustained ALT normalization with loss of HCV RNA was seen in 12/62 (19%) of the children within 30 months of life; 66% of the infants had developed an ALT peak greater than 5x normal at onset (vs. 28% of children with persistent viremia; P < 0.05), and 50% had HCV genotype 3 (vs. 17% of viremic children). Conversely the cumulative probability of chronic progression was 81%. Chronic infection was asymptomatic and liver disease was mild in all 11 children who underwent a biopsy. In conclusion the early stage of acquired perinatally HCV infection is characterized by a wide range of ALT abnormalities, suggesting the interaction of multiple host and virus factors. The chronic progression rate of infection is high, but the associated liver disease is usually mild. High ALT levels at onset seem to offer greater opportunity of biochemical remission and loss of viremia during follow-up.