Posttransfusion hepatitis C virus infection in children

The natural history of hepatitis C virus infection acquired during childhood

BACKGROUND

The outcome of patients with hepatitis C virus (HCV) infection acquired during childhood in the absence of antiviral therapy is not clear.

AIMS

The purpose of this study was to review the outcome of untreated HCV acquired in childhood. Only population-based studies were included, as referred cases would be predicted to have more severe disease.

METHODS

A systematic review of the literature was completed up to October 2010 to identify studies where a population was screened for HCV infection that was presumably acquired during childhood. Demographical and clinical data were collected on infected patients who had not been treated with an antiviral. Primary outcome was development of a severe adverse outcome (cirrhosis, hepatoma, need for a liver transplant or liver-related death).

RESULTS

There were 25 studies reporting a total of 733 infected patients. Liver biopsy results were provided for 180 patients (25%), revealing cirrhosis in eight (1.0% of the total and 4.0% of those who had a biopsy). None of the other patients developed a severe adverse outcome. As a result of the small number of patients with a severe adverse outcome, risk factors for HCV progression could not be identified.

CONCLUSION

Although HCV can lead to liver transplantation and death during childhood, the vast majority of patients with disease acquired during childhood have slowly progressive disease. There is no clear indication for antiviral therapy in the majority of children with HCV infection.

Clinical outcomes of Torque teno virus-infected thalassemic patients with and without hepatitis C virus infection

Background

Although a marked proportion of thalassemic patients acquire Torque teno virus (TTV) through blood transfusion, its clinical importance is unclear. This study was designed to investigate the clinical importance of TTV infection in thalassemic patients with and without hepatitis C virus (HCV) co-infection in Iran.

Methods

In this case-control study, 107 thalassemic patients on chronic transfusion and 107 healthy individuals were selected. According to HCV and TTV infection status (detected by semi-nested PCR), patients were categorized into 4 groups: TTV and HCV negative, TTV positive, HCV positive, and TTV and HCV positive. Blood ferritin, alanine aminotransferase (ALT), and aspartate aminotransferase (AST) levels in these 4 groups were assessed.

Results

Approximately half of the thalassemic patients (50.5%) and 27.1% of controls had TTV infection. Thalassemic patients had a greater chance of TTV infection compared to the control group with a sex-adjusted OR of 4.13 (95% CI=2.28-8.13). The increased levels of ALT, AST, and ferritin in the TTV and HCV-infected group were not significantly different from those in the TTV and HCV negative group. Co-infection with TTV and HCV did not significantly increase ALT, AST, and ferritin levels compared to infection with TTV alone.

Conclusion

Although common in thalassemic patients, TTV infection appears to have a negligible role in increasing the severity of liver disease, even when co-infection with HCV occurs.

Chronic hepatitis C virus infection in children

The importance of hepatitis C viral infection in the health care of children has grown in recent decades. More is now known about the epidemiology of this infection in children and the progression of disease in the pediatric age group, and the treatment options are increasing. In this review, we update readers on the state of our understanding of hepatitis C infection in children, provide the current recommendations for monitoring and treatment, and discuss emerging therapies.

Changing prevalence of hepatitis C virus infection among teenagers in an endemic area in Taiwan

Tzukuan Township in Taiwan has been reported to be an endemic area for hepatitis C virus (HCV) infection both in adults and adolescents. The maritime part of the township carries a higher prevalence than the non-maritime part and, as a consequence, several public education strategies have been introduced during the past decade. The current follow-up study aimed to clarify the changing prevalence of HCV infection among teenagers in the endemic maritime part of Tzukuan. In addition to viral hepatitis markers and biochemical profiles, we compared the epidemiological characteristics of 887 and 394 teenagers (aged 13-16 years) from the maritime part enrolled in 1995 and 2005, respectively. Compared with the results of surveillance in 1995, the prevalence of anti-HCV seropositivity (1.0% vs. 2.8%; P=0.045) and HCV RNA (0.5% vs. 2.3%; P=0.026) had decreased significantly by 2005. Transfusions and anti-HCV-positive families were the main risk factors amongst the 25 anti-HCV-positive teenagers in 1995, and became non-significant amongst the four anti-HCV-positive teenagers in 2005. In conclusion, the seroprevalence of HCV infection has significantly decreased after one decade of intervention among the teenage population in this endemic area.

Hepatitis C virus infection among children in aboriginal areas in Taiwan

The prevalence of hepatitis C virus (HCV) infection among adults in aboriginal areas has been shown to be higher than in urban areas in Taiwan. Whether the prevalence of HCV infection is also higher among children in aboriginal areas remains unclear. In total, 1176 schoolchildren in four aboriginal areas were invited to participate in the study. All children were tested for serum antibodies to HCV (anti-HCV) and liver enzymes. The age range of children was 6-13 years. Another 606 sex- and age-matched schoolchildren from an urban area served as controls. There was no statistically significant difference in prevalence of anti-HCV between aboriginal and Han Chinese students in aboriginal areas. The prevalence of anti-HCV was 0.3% (4/1176) in aboriginal areas, which was similar to the prevalence of 0% (0/606) in the urban area. The four anti-HCV seropositive aboriginal children were all negative for HCV RNA. Our data suggest that the high prevalence of anti-HCV among aboriginal adults might be due to subsequent exposure to risk factors after school age.

SEN virus infection in children in Taiwan: transmission route and role in blood transfusion and liver diseases

BACKGROUND

SEN virus (SENV) is a newly discovered DNA virus. We conducted this study to evaluate potential modes of SENV transmission and the pathogenic effect of SENV on liver diseases in children.

METHODS

Polymerase chain reaction was used to detect 2 SENV variant (SENV-D and SENV-H) DNA in sera from healthy individuals and diseased children. Nucleotide sequence of SENV was determined by direct sequencing.

RESULTS

SENV infection was assessed in healthy individuals, including 50 newborns (sera collected from the umbilical cord), 24 infants, 46 preschool children (aged 1-6 years), 42 school children of an age before that of the first sexual experience (aged 7-12 years), 62 adolescents (13-18 years), 72 young adults (19-30 years) and 32 adults (>30 years). The prevalence of SENV-D and/or SENV-H (SENV-D/H) viremia in each group was 0%, 17%, 24%, 24%, 27%, 33% and 40%, respectively. The prevalence of SENV-D/H viremia in 18 children with non-A to E hepatitis, 64 thalassemic children, 80 children transfused during cardiac surgery, 30 children with chronic hepatitis B, 9 children with chronic hepatitis C and 32 infants with biliary atresia was 11%, 61%, 80%, 83%, 67% and 50%, respectively. SENV was found more frequently in all patient groups than in 174 age-matched controls (P < 0.01), with the exception of non-A to E hepatitis (11% versus 24% in the control group; P = 0.27). In 2 infants with proven intrauterine hepatitis B viral infection, identical SENV-D nucleotide sequence existed in both the maternal and neonate serum. Elevated alanine aminotransferase concentrations were rarely observed in children who acquired isolated SENV viremia because of transfusion for surgery. Infection with SENV in children with chronic hepatitis C virus or hepatitis B viral infection was not associated with higher peak alanine aminotransferase values.

CONCLUSION

SENV is transmitted mainly via nonparenteral daily contact and frequently occurs early in life. Transfusion can significantly increase the rate of SENV viremia. SENV does not appear to cause hepatitis in children.

Seroprevalence of hepatitis C virus among blood donors in Rivers State, Nigeria

Anti-HCV pre-transfusion testing among blood donors has not been introduced as a mandatory test in Rivers State, hence the risk of transfusion-transmitted HCV cannot be fully ascertained. One thousand (1000) apparently healthy blood donors were screened using a rapid second - generation test, the HEP C SPOT HCV assay. An overall prevalence of 2.9% was observed in this study. The highest prevalence (8.1%) was found among adults aged between 26 and 33 years and commercial donors.

HCV infection in very-long-term survivors after cancer chemotherapy and bone marrow transplantation: a single-center experience

The long-term evolution of hepatitis C virus (HCV) infection in oncologic and/or transplanted patients is still unknown. Patients treated for cancer are different from the general HCV-infected population because of the immunosuppression and the hepatotoxic treatments, which act as co-factors of liver damage. Recently it was observed that antimetabolites play a role in accelerating the process of hepatic fibrosis. The aims of this retrospective study were to describe the clinical course of chronic hepatitis C acquired during anticancer treatment in a group of patients referred to a single center, and to correlate the course of hepatic disease to the type of treatment they received. Among the 17 children who underwent very long follow-up (range 10-18.5 years), the authors identified a group with more active hepatic cytolysis through the serial observation of mean ALT values, HCV RNA determination, and histologic data when available. During follow-up, none of them developed hepatic failure, cirrhosis, or hepatocarcinoma. No single risk factor, such as exposure to antimetabolites, alkylating agents, or other chemotherapy, radiotherapy to the abdomen, exposure to other hepatotoxic drugs, appearance of vaso-occlusive disease, acute and/or chronic graft-versus-host disease, or length of immunosuppression, correlated with a worse course of hepatitis. No definitive conclusions can be drawn. However, multivariate analysis of hepatic risk factors in larger cohorts of patients will be able to provide us with more precise information about the clinical outcome of chronic hepatitis in survivors.

Long-term outcome of vertically acquired and post-transfusion hepatitis C infection in children

BACKGROUND AND AIM

To determine the natural history of perinatally acquired hepatitis C virus (HCV) infection, clinical and laboratory outcomes among 31 children with HCV infection were retrospectively reviewed. Fifteen children had acquired HCV by blood transfusion (BT) prior to 6 months of age and 16 had vertically acquired (VT) HCV.

METHODS

Demographic data, clinical symptoms and signs, liver biochemistry, HCV antibody, HCV-RNA and liver histology were evaluated.

RESULTS

Mean age at last visit was 13.0 years (range 9.0-16.8 years) in the BT group and 8.6 years (range 0.5-18.1 years) in the VT group. There were no abnormal clinical findings of chronic liver disease in either group. Estimated HCV-RNA clearance rate was 19%, with no significant difference between the groups. In HCV-RNA-negative children (n = 6), two lost anti-HCV antibody and two developed indeterminate anti-HCV antibody results, while all HCV-RNA-positive children (n = 25) remained both anti-HCV antibody positive and HCV-RNA positive throughout follow up. The alanine aminotransferase level was significantly higher in the VT group than in the BT group during the first 5 years of life. Liver biopsy, which was carried out in four children, revealed mild to moderate fibrosis and/or necroinflammatory activity, but no cirrhosis.

CONCLUSIONS

Outcomes among children with HCV acquired in infancy demonstrate asymptomatic and slowly progressive disease, at least for the initial decade of infection. Mode of acquisition appears to have a limited impact on outcomes, with similar viral clearance and anti-HCV antibody seroreversion rates in vertical and transfusion acquired infection.

Treatment of chronic hepatitis C in children

Since the discovery of hepatitis C virus (HCV) in 1989, significant advances have been made in our understanding of this important viral pathogen. Children at risk for HCV infection include recipients of potentially contaminated blood products and organ transplants, and infants born to HCV-infected mothers. Chronic HCV infection is usually asymptomatic in children but active hepatitis, cirrhosis and hepatocellular carcinoma can occur. The development of treatment strategies for chronic hepatitis C in children has directly evolved from clinical trials in adults. Sustained virologic response, defined by undetectable HCV RNA in serum 24 wk after completion of treatment, occurs in approximately 36% of children treated with conventional interferon alone and in about 50% of those given conventional interferon in combination with ribavirin. Pegylated interferon-based treatment regimens are better than those based on conventional interferon in adults but little is known about pegylated interferon in children. Factors associated with a favorable response to antiviral therapy in children are similar to those in adults and include infection with HCV genotype 2 or 3 and low pretreatment serum HCV RNA levels. Treatment related adverse events in children include 'flu-like' syndrome, fatigue, anorexia, weight loss, depression, anemia, leukopenia and thrombocytopenia.

A higher than expected recovery rate from hepatitis C infection amongst adolescents: a community study in a hepatitis C-endemic township in Taiwan

This study investigated the prevalence of antibody to hepatitis C virus (anti-HCV), evaluated clinical manifestations of hepatitis C, and explored the risk factors amongst adolescents in an HCV-hyperendemic area in Taiwan. In December 1999, 713 students aged 13-16 years from Taishi township, in central Taiwan, were enrolled in a screening program for anti-HCV and alanine transaminase (ALT) status. Fourteen participants (M/F = 6/8) were positive for anti-HCV. Eight of the 14 later proved to be negative for HCV RNA, and they demonstrated relatively low sample rate/cut-off rate (S/CO) ratios (1.05-11.83) for anti-HCV tests. All HCV RNA negative cases had normal serum ALT levels. The other six (43%) seropositive students demonstrated HCV viraemia and greater S/CO ratios (25.66-77.49). Two of these six participants had elevated serum ALT levels. Compared to anti-HCV-negative subjects, anti-HCV-positive students exhibited significantly greater rates of exposure to one or more of the following: blood transfusion, tattooing, and earlobe piercing. This study group has a greater prevalence (2%) of anti-HCV than the general Taiwanese population at the same age. The study also reveals a lower rate (43%) of chronicity of HCV infection than that reported in the literature.

TT virus infection in healthy children, children after blood transfusion, and children with non-A to E hepatitis or other liver diseases in Taiwan

Serum samples from healthy and diseased children were studied for the presence of TTV DNA by nested PCR using primer sets generated from N-22 region and from the untranslated region (UTR) of the viral genome. N-22 positive TTV DNA was detectable in 33 (27%) of 122 healthy children, 47 (73.4%) of 64 polytransfused thalassemic children, 37 (46.3%) of 80 children who received transfusion during cardiac surgery, 8 (42.1%) of 19 non-A to E hepatitis, 10 (33.3%) of 30 HBV carrier children, and 5 (15.6%) of 32 infants with biliary atresia. A much higher prevalence of TTV DNA with rates varying from 78-100% in the above study groups was observed using the UTR primers. For children with N-22 positive TTV DNA, biochemical assessment of isolated TTV viremia in thalassemic children or children transfused during surgery showed no convincing association between raised ALT levels and TTV viremia. Coinfection with TTV in chronic HCV-infected or HBV-infected children did not result in higher peak ALT levels during follow-up, suggesting that TTV has no synergistic pathogenic effect. The phylogenetic analysis of the N-22 positive TTV DNA isolates revealed that most isolates from healthy children, children transfused during surgery, and non-A to E fulminant hepatitis children were type 1 TTV. These results indicate that TTV infection in children was significantly associated with transfusion. TTV infection is highly prevalent in early childhood in Taiwan but plays a minimal role in the induction of hepatitis in children.

Children with hepatitis C

An estimated 240,000 children in the United States have antibody to hepatitis C virus (HCV) and 68,000 to 100,000 are chronically infected with HCV. Acute HCV infection is rarely recognized in children outside of special circumstances such as a known exposure from an HCV-infected mother or after blood transfusion. Most chronically infected children are asymptomatic and have normal or only mildly abnormal alanine aminotransferase levels. Although the natural history of HCV infection acquired in childhood seems benign in the majority of instances, the infection takes an aggressive course in a proportion of cases leading to cirrhosis and end-stage liver disease during childhood; the factors responsible for a more aggressive course are unidentified. An optimal approach to management of hepatitis C in children would be prevention, particularly of perinatal transmission, which is now the major cause of new cases of hepatitis C in children. Obstetrical factors may be important determinants of transmission, which, if confirmed, should lead to changes in the care of infected women. Therapy of HCV infection in children is also not well defined. There have been no large randomized, controlled trials of therapy in children with chronic hepatitis C. Small heterogeneous studies of interferon monotherapy have reported sustained virological response rates of 35% to 40%. There are few data regarding the use of combination therapy with interferon and ribavirin in children and no information on the use of peginterferon. Clearly, there are important needs for future epidemiologic and clinical research on hepatitis C in childhood.

Children with hepatitis C

An estimated 240,000 children in the United States have antibody to hepatitis C virus (HCV) and 68,000 to 100,000 are chronically infected with HCV. Acute HCV infection is rarely recognized in children outside of special circumstances such as a known exposure from an HCV-infected mother or after blood transfusion. Most chronically infected children are asymptomatic and have normal or only mildly abnormal alanine aminotransferase levels. Although the natural history of HCV infection acquired in childhood seems benign in the majority of instances, the infection takes an aggressive course in a proportion of cases leading to cirrhosis and end-stage liver disease during childhood; the factors responsible for a more aggressive course are unidentified. An optimal approach to management of hepatitis C in children would be prevention, particularly of perinatal transmission, which is now the major cause of new cases of hepatitis C in children. Obstetrical factors may be important determinants of transmission, which, if confirmed, should lead to changes in the care of infected women. Therapy of HCV infection in children is also not well defined. There have been no large randomized, controlled trials of therapy in children with chronic hepatitis C. Small heterogeneous studies of interferon monotherapy have reported sustained virological response rates of 35% to 40%. There are few data regarding the use of combination therapy with interferon and ribavirin in children and no information on the use of peginterferon. Clearly, there are important needs for future epidemiologic and clinical research on hepatitis C in childhood.

Full-length core sequence dependent complex-type glycosylation of hepatitis C virus E2 glycoprotein

AIM

To study HCV polyprotein processing is important for the understanding of the natural history of HCV and the design of vaccines against HCV. The purpose of this study is to investigate the affection of context sequences on hepatitis C virus (HCV) E2 processing.

METHODS

HCV genes of different lengths were expressed and compared in vaccinia virus/T7 system with homologous patient serum S94 and mouse anti-serum M( E2116) raised against E.coli -derived E2 peptide, respectively. Deglycosylation analysis and GNA ( Galanthus nivalus ) lectin binding assay were performed to study the post-translational processing of the expressed products.

RESULTS

E2 glycoproteins with different molecular weights (-75 kDa and -60 kDa) were detected using S94 and M( E2116), respectively. Deglycosylation analysis showed that this difference was mainly due to different glycosylation. Endo H resistance and its failure to bind to GNA lectin demonstrated that the higher molecular weight form (75 kDa) of E2 was complex-type glycosylated, which was readily recognized by homologous patient serum S94. Expression of complex-type glycosylated E2 could not be detected in all of the core-truncated constructs tested, but readily detected in constructs encoding full-length core sequences.

CONCLUSION

The upstream conserved full-length core coding sequence was required for the production of E2 glycoproteins carrying complex-type N-glycans which reacted strongly with homologous patient serum and therefore possibly represented more mature forms of E2. As complex-type N-glycans indicated modification by Golgi enzymes, the results suggest that the presence of full-length core might be critical for E1/E2 complex to leave ER. Our data may contribute to a better understanding of the processing of HCV structural proteins as well as HCV morphogenesis.

Diagnosis and management of paediatric hepatitis C virus infection

Hepatitis C virus (HCV) infection in children is uncommon and there are few guidelines indicating optimal management. It is estimated that 125-250 children are infected vertically with HCV in Australia each year and very few of these children are diagnosed and followed medically. Without accurate diagnosis and follow up, these children cannot be offered optimal care, and are at risk of presenting in adult life with significant liver pathology and long-term sequelae.

Challenges in the treatment of hepatitis C in children

Hepatitis C infection in children is associated with a unique set of challenges for clinicians and investigators. Although the prevalence of HCV infection is lower in children than in adults, it is important to identify infected children to monitor progression of liver disease and to make appropriate interventions to minimize factors that may exacerbate progression. Identification requires understanding of risk factors important in children, primarily exposure at or near the time of birth. The natural history of this infection in most children is either more benign or significantly prolonged than that of infection acquired in adulthood. Reasons for this difference in natural history must be explored and possibly even exploited in the care of adult patients with HCV infection. Identification of appropriate pediatric candidates for treatment and definition of optimal therapy for these children require ongoing study. Lastly, as perinatal transmission becomes the primary mode of acquisition for new pediatric infections, factors that increase or decrease the likelihood of this transmission must be identified, and effective preventive interventions must be put into practice. There are important differences in the clinical features, natural history, and response to therapy between pediatric and adult patients with HCV infection. Understanding of these differences will allow optimal care for affected children and perhaps better understanding of the pathophysiology and pure natural history of this disease.

Prospective study of mother-to-infant transmission of hepatitis C virus

BACKGROUND

Mother-to-infant transmission of hepatitis C virus (HCV) could become the main route of HCV infection in the future because there are no methods available to prevent vertical infection. The aim of this study was to determine the incidence of mother-to-infant transmission in infants born to mothers who tested positive for anti-HCV antibodies and to elucidate associated risk factors for transmission.

METHODS

Screening was conducted for 16,800 pregnant women with an anti-HCV antibodies test, and 154 mothers were positive. From the positive group 141 mothers were enrolled in the study and their 147 infants were followed from birth for serum alanine aminotransferase activity, anti-HCV antibodies and HCV RNA. HIV infection was tested in 73 of 141 mothers, all of whom were negative.

RESULTS

Thirty-three infants were dropped from the study because they were followed for <6 months or were not tested adequately. Of the 114 infants finally evaluated 9 (7.8%) had detectable HCV RNA. The transmission rate was not influenced by the mode of delivery [vaginal delivery, 8 of 90 vs. cesarean section, 1 of 24 (P = 0.396)] or by the type of feeding [9 of 98 for breast-fed infants vs. 0 of 16 for formula-fed infants (P = 0.243)]. All infected infants were born to mothers who had HCV viremia at the delivery (P = 0.040) and to those with a high viral load (P = 0.019).

CONCLUSIONS

Our prospective study showed that the transmission rate of mother-to-infant HCV infection was 7.8% in anti-HCV antibody-positive mothers. Risk was related to the presence of maternal HCV viremia at delivery and a high viral load in the mothers.

Treatment of chronic hepatitis C virus infection in children

Hepatitis C virus (HCV) infection may occur in infants and children, although it is much less common than it is in adults. The main transmission routes include mother-to-infant transmission, use of HCV infected blood products, unsterile needles or syringes and other invasive procedures. The natural course of HCV infection in children is variable: some (20-40%) develop an acute resolving infection and spontaneous regression occurs in approximately one-third of infants of HCV infected mothers before 2 years of age. Approximately 60-80% of HCV infected children develop a chronic infection with varying degrees of activity and fibrosis, mostly mild during childhood. However, the potential risks of liver cirrhosis and hepatoma during later life are obvious. Interferon is the main agent used to treat HCV infection in children. The response to interferon at the end of 4-12 months of therapy ranges from 25-90%. A sustained response was found in 36-56% of children 6-36 months after the end of therapy. The duration of therapy is recommended to be 12 months. At the end of 3 months, an evaluation of the response is indicated in the majority of children, except those with thalassemia, in whom evaluation of response should be conducted at the end of 6 months of therapy. The benefit of other therapies, such as combination therapy with interferon and ribavirin in children with hepatitis C is currently under investigation.

Treatment of chronic hepatitis C in pediatric patients

Although HCV infection in children shares some clinical features with that in adults, it is clearly different in several ways. These differences may have important implications for treatment. Some differences, such as milder disease, less frequent extrahepatic manifestations, and fewer comorbid conditions causing progression, argue against aggressive treatment in childhood. Other factors, such as less severe liver disease, shorter disease duration, possibly higher rates of sustained virologic response, and better tolerance of IFN, may be reasons to pursue treatment before advanced hepatic injury occurs. Given the relatively small number of pediatric patients with HCV infection and the gaps in the current understanding of natural history and effects of therapy in these patients, treatment should be undertaken only in clinical trials, so that careful data collection and monitoring can define more precisely the safety and efficacy of IFN therapy in children.

Antibodies to E2 protein of hepatitis G virus in children: different responses according to age at infection

OBJECTIVES

To study viral persistence and antibody responses after hepatitis G virus (HGV) infection in children of various ages.

STUDY DESIGN

We performed an enzyme immunoassay for antibodies to E2 protein (anti-E2) of HGV and reverse-transcription polymerase chain reaction assay for HGV RNA on serum samples.

RESULTS

Of 28 infants born to HGV RNA-positive mothers, 17 were found to be positive for HGV RNA. None were positive for anti-E2. All 17 infected infants continued to have viremia except 1 who converted to HGV RNA-negative status at 24 months. Six infants had mild elevations of alanine aminotransferase levels (5 HGV-positive and 1 HGV-negative). An additional 14 HGV-infected children (aged 6 months to 14 years) with posttransfusion HGV infection were tested for anti-E2 3 months and 12 months after blood transfusion. None of the HGV RNA-positive serum samples were positive for anti-E2; however, 4 of the 8 children with resolving HGV infection were positive for anti-E2 1 year later.

CONCLUSIONS

Mother-to-infant transmission of HGV resulted in a high viral persistence rate and lack of immune responses to HGV. In contrast, anti-E2 appeared in children who recovered from posttransfusion HGV infection. Mode of transmission and age at infection may be important factors in determining persistent HGV infection and defective immune response to HGV.

De novo hepatitis C in children after liver transplantation

BACKGROUND

We describe the incidence, results of interferon therapy, and outcome of hepatitis C virus (HCV) hepatitis occurring de novo after pediatric orthotopic liver transplantation (OLT).

METHODS AND RESULTS

Of children undergoing OLT between 1984 and September 1996, 321 children survived for more than 1 year. Of these, 13 (4.0%) developed previously undiagnosed HCV disease, as suggested by HCV antibody testing and HCV polymerase chain reaction and confirmed by liver biopsy. Of the 117 children who received transplants before HCV screening of blood products or donors, 10.2% developed de novo HCV disease. The mean age at diagnosis of HCV hepatitis was 13.2+/-5.0 years, and the mean time to diagnosis after OLT was 8.1 years (range, 4-11 years). The mean alanine aminotransferase (ALT) level at diagnosis was 108 IU/ml, and the liver biopsy specimen showed chronic active or chronic persistent hepatitis in 11 children, cirrhosis in 1 child, and nonspecific changes in 1 child. Twelve children were treated with interferon-2alpha; children who weighed > or =20 kg received 3 x 10(6) units every other day, and those who weighed <20 kg received 1.5 x 10(6) units every other day. Four patients developed rapidly progressive liver failure while receiving interferon therapy and required urgent re-transplantation. Three of the four children again developed histologic evidence of recurrent HCV 4-6 months after the second OLT, and all three subsequently died of HCV-induced liver failure. One patient remains alive and well with no evidence of HCV recurrence and a negative HCV RNA. Of the remaining eight children treated with interferon, only two have had a sustained response (normal ALT) and one is now HCV RNA negative. HCV RNA levels did not correlate with outcome or disease severity. HCV antibody levels were unreliable, with two patients having negative HCV antibody but a positive HCV RNA at diagnosis. Six patients were able to be genotyped: four were la and two were 1b.

CONCLUSION

Overall mortality for de novo HCV hepatitis was 23%. Seventy-five percent of children who received a second transplant for HCV hepatitis had early histologic recurrence that led to liver failure and death. Interferon therapy resulted in a sustained improvement in ALT in only 15% of children. The time to onset and progression of clinical disease both in the original graft and the retransplant graft were accelerated compared with nonimmunosuppressed individuals.

Chronic hepatitis virus infection in children

Hepatitis B and C viruses (HBV and HCV) are the two main hepatitis viruses causing chronic liver diseases in children. In hyperendemic areas, nearly half of the primary infection in chronic HBV carriers occurs during the perinatal period through the transmission from hepatitis B e antigen (HBeAg)-positive mothers. The other half are from horizontal transmission mainly through intrafamilial spread or injection using unsterilized needles. During the natural course of chronic HBV infection, spontaneous HBeAg/anti-HBe seroconversion occurs very rarely (2% annually) before 3 years of age. After 3 years of age, the HBeAg seroconversion rate increases gradually to 5% per year. Those with mothers who are hepatitis B carriers tend to clear HBeAg slower than those whose mothers are non-carriers. Transplacental HBeAg may cause T cell tolerance in infected children. Universal HBV immunization programmes have been effective in reducing the hepatitis B carrier rate more than 10-fold, and the incidence of hepatocellular carcinoma in children has also been decreased significantly. Hepatitis C virus infection occurs mainly in high-risk children, such as those who received blood products (blood diseases, malignancies, post-open heart surgery etc.), children of HCV-infected mothers, and in hyperendemic areas, from injection using unsterile needles. Mother-to-infant transmission occurs on average in 5% of infants of viraemic mothers. The maternal HCV-RNA titre is the most important factor determining the infectivity. Chronicity developed in 60-80% of HCV-infected children. Although transient or persistent elevation of aminotransferases occurs frequently in chronically HCV-infected children, liver histology showed minimal or mild changes only. The most prevalent genotype of HCV in children is Ib. Screening of the blood products for HCV antibody has markedly reduced the rate of HCV infection in children at risk. However, vaccine development is needed to prevent mother-to-infant transmission and other routes of infections.

Prevalence and manifestations of hepatitis C seropositivity in children in an endemic area

BACKGROUND

According to our previous studies, Paisha Township in Penghu Islets is an endemic area for hepatitis B virus and hepatitis C virus (HCV) infection and for hepatocellular carcinoma. We conducted this study to understand the prevalence of anti-HCV seropositivity among children in this area and to observe clinical manifestations of anti-HCV-positive children.

METHODS

In March, 1994, 1164 (93.6%) of 1243 students from all 6 kindergartens, 9 primary schools and 3 middle schools in Paisha Township participated in the screening for anti-HCV by enzyme immunoassay with second generation commercial kits (Abbott EIA 2.0). Anti-HCV tests were duplicated for the positive sera in 2 laboratories. All anti-HCV-positive children were followed annually for 2 years.

RESULTS

The prevalences of children from kindergartens (ages 3 to 6 years), primary schools (ages 7 to 12 years) and middle schools (ages 13 to 15 years) were 0% (0 of 229), 0.8% (5 of 617) and 1.9% (6 of 318), respectively. Initially the optic density (OD) values of anti-HCV were > 2.0 in 4 cases (36%), between 1.0 and 2.0 in 2 cases, and < 1.0 in the other 5 cases. None had sonographic parenchymal changes in the liver. In the 2-year follow-up of the anti-HCV-positive subjects, type 2a HCV-RNA persisted in 3 of 4 children with an OD of anti-HCV more than 2.0; 2 of them had 2 elevations of alanine transaminase values. Four of 7 children with an OD of 2.0 or less had a decrease in OD values in the follow-up examinations, and 2 of them became anti-HCV-negative.

CONCLUSION

Only 36% (4 of 11) of anti-HCV-positive children had an OD of > 2.0. Subjects with sequentially low OD might recover from chronic HCV infection without detectable HCV RNA and with normal alanine aminotransferase values.

Hepatitis G virus infection in normal and prospectively followed posttransfusion children

A recently identified RNA virus, hepatitis G virus (HGV), has been investigated for its role in causing non-A-E hepatitis. The frequency and clinical outcome of HGV infection in children was studied. Two hundred apparently healthy children aged 6 mo to 12 y, and 90 children who had undergone open heart surgery in a prospective study for posttransfusion hepatitis were included in this study. The serum samples were tested for HGV RNA by nested reverse transcription-PCR with primers from the 5'-untranslated region. The HGV RNA viremic rate was found to be 1% (2/200) in apparently healthy children, 30% in children after open heart surgery. Among the 90 children, three were HGV-infected before the surgery. Twenty-four (28%) of the remaining 87 children tested positive for HGV RNA within 6 mo after the surgery. Sixty-five percents of these viremic children eventually became persistently infected at 1 y after surgery. No HGV RNA-positive children exhibited elevated alanine aminotransferase levels during the follow-up period. No coinfections of HGV with the hepatitis C virus or hepatitis B virus were found. Patients of younger age appeared more likely to become chronic carriers. Anti-HCV screening did not reduce the prevalence of HGV infection. In conclusion, in children with open heart surgery, the risk of transfusion-transmitted HGV infection and the chronicity rate have been found to be high. Young age is a risk factor of persistent infection.

Hepatitis C virus infection in pediatric patients

In contrast to our understanding of hepatitis C virus infection in adults, relatively little is known about the evolution and treatment of HCV infection in pediatric patients. Children at risk for HCV infection include recipients of multiple blood-product transfusions, organ transplantation and infants born to HCV-infected mothers. A proportion of HCV-infected pediatric patients do not have an identifiable risk factor. HCV infection is commonly detected in children previously presumed to have non-A, non-B hepatitis and cryptogenic liver disease. HCV infection usually leads to mild chronic liver disease in children but is also associated with chronic active hepatitis and cirrhosis. Interferon therapy is effective in a proportion of patients with chronic hepatitis C.

Distribution of hepatitis C virus genotypes among blood donors in Taiwan

The aim of this study was to investigate the prevalence and distribution of hepatitis C virus (HCV) genotypes of blood donors in Taiwan. RNA was extracted from the serum of anti-hepatitis C virus-positive carriers and this was followed by reverse transcriptase-polymerase chain reaction (RT-PCR) using type-specific primers for the presence of HCV genotypes, 1a, 1b, 2a, 2b, 3a and 6a. Of the 604 anti-HCV-positive specimens, the PCR demonstrated that 93.0% (562/604) were positive for at least one HCV genotype. The remaining 42 specimens (7%) were HCV negative. Among the 562 HCV-positive specimens, 505 (89.8%) contained HCV 1a, 1b, 2a, 2b and 3a as the only genotype, with a prevalence of 0.4% (2/562), 60.1% (338/562), 15.5% (87/562), 11.9% (67/562), and 2.0% (11/562), respectively. No HCV genotype 6a was found. Thirty-seven specimens (6.6%) exhibited mixed infections with multiple HCV genotypes that included types 1b, 2a and 2b, while 20 (3.5%) HCV RNA-positive sera remained unclassified. These results confirm that the predominant HCV genotype in Taiwan is 1b. In addition, genotypes 1a and 3a can also be found in Taiwan at low frequency.

Evolution of hepatitis C virus quasispecies in mothers and infants infected through mother-to-infant transmission

BACKGROUND/AIMS

Two mother-infant pairs (Pair H and P) were studied to determine the evolution of hepatitis C virus (HCV) quasispecies.

METHODS

Eight clones of the hypervariable region of HCV cDNA from the infants' sera sampled at the age of 3 months, 1, 2, and 3 years and the time-corresponding maternal sample were also sequenced. The sequences were analyzed by the nucleotide diversity, substitution rate, and phylogenetic studies.

RESULTS

HCV quasispecies of the infants were more homogeneous than those of their mothers, particularly at the age of 3 months (nucleotide diversity, pi = 0.18 x 10(-2)/site in infant H, and 0.22 x 10(-2)/site in infant P). The nucleotide substitution rate in infants also increased as they aged, from 1.2 x 10(-2) to 4.46 x 10(-2)/site/year in infant H, and from 0.21 x 10(-2) to 4.88 x 10(-2)/site/year in infant P respectively. The nucleotide sequence differences between infants and mothers increased from 2.63 x 10(-2) to 9.06 x 10(-2)/site in Pair H, and from 1.85 x 10(-2) to 5.33 x 10(-2)/site in Pair P within 3 years. Phylogenetic studies suggest the infants' initial quasispecies were closely related to their mothers', while they evolved differently. HCV RNA titer was stable during follow-up and the infants' titer was similar to their mothers'. The fluctuations in titer did not correlate with nucleotide diversity.

CONCLUSIONS

HCV quasispecies evolved differently in each individual, even though they were genetically linked. The sequence in infants was not a complex as in their mothers.

Mode of hepatitis C virus infection, epidemiology, and chronicity rate in the general population and risk groups

Since the discovery of the hepatitis C virus (HCV), it has become evident that this infectious agent is a primary cause of posttransfusion and sporadic non-A, non-B hepatitis. Identification and introduction of surrogate markers for posttransfusion hepatitis and later introduction of anti-HCV screening has decreased the incidence of posttransfusion hepatitis. Community-acquired HCV infection is less common than posttransfusion HCV hepatitis. HCV infection may lead to liver cirrhosis without prior evidence of laboratory or histologic infection. Populations at risk for HCV infection include patients receiving organ transplants, health care workers, infants born to HCV-infected mothers, and hemodialysis patients. Intravenous drug abusers and their sexual partners also demonstrate a high rate of HCV infection. Nosocomial HCV transmission may occur despite the observance of universal precautions. Dental or surgical intervention, salivary inoculation, family members infected with HCV, cocaine abuse, HIV infection, and lower socioeconomic status also each correlate with an increased risk of infection. HCV infection is associated with many immune-mediated diseases. There may also be some relationship between human leukocyte antigens and HCV infection. Since there currently is no HCV vaccine, prevention of exposure remains the only possibility for reducing HCV transmission and prevalence.

Chronic viral hepatitis in childhood

In endemic areas infection with hepatitis B virus is a common cause of chronic liver disease in childhood. High levels of viral replication and mild ALT abnormalities are the rule in children infected perinatally and many of them are likely to maintain viral replication through their youth. Conversely about 90% of children infected later in life clear HBeAg and achieve sustained remission of liver disease before reaching adulthood. The eventual outcome of infection and disease in these patients remains unpredictable as reactivation of liver damage and viral replication may occur after several years of sustained remission. Cirrhosis is a rare and early complication of chronic HBV infection in children, and a risk factor for hepatocellular carcinoma. IFN therapy can accelerate HBV DNA clearance, improving the spontaneous anti-HBe seroconversion rate in Caucasian children by two to three times. Hepatitis delta is the most severe form of chronic viral hepatitis in childhood. Cirrhosis can be diagnosed in up to 26% of patients at presentation, and few cases respond to IFN therapy. Hepatitis C is relatively rare in children. Before the discovery of HCV, blood transfusions were the most common source of infection. Hepatitis C is usually a mild, asymptomatic disease in otherwise healthy children, but has a poor propensity to spontaneous remission over the years. For this reason, and based on the experience in adults, IFN treatment is now being evaluated.

Hepatitis C viral infection in thalassemic children: clinical and molecular studies

To determine and correlate the liver function profile, hepatitis C virus (HCV) genome, anti-HCV, genotypes, quantitation, and nucleotide sequence variability in polytransfused thalassemic children, 61 such children were studied prospectively for 4 y. Twenty-six had HCV infection. The average age, number of transfusions, and alanine aminotransferase (ALT) levels of the HCV-infected group were higher than those of the 35 children without HCV infection. None was infected after the initiation of anti-HCV screening in donor blood. Liver biopsies were performed in six HCV-infected and eight HCV-noninfected thalassemic children, and portal fibrosis was found more frequently in the HCV-infected group. Quantitation of HCV RNA was done by the competitive polymerase chain reaction method, and the titer was about 1 x 10(6) to 5 x 10(8) copies/mL. The titer did not change significantly over the 4-y follow-up period and did not correlate with ALT levels. Nineteen HCV-infected patients were genotyped; 15 were Okamoto/Simmonds type II/1b, two were type III/2a, and two were type IV/2b. The hypervariable region of the HCV genome (E2/NS1) was cloned and sequenced in two serum samples from one patient collected at a 2-y interval, as the ALT levels decreased. The variation rate was estimated to be 1.2-1.7 x 10(-2)/nucleotide/y. The results showed that, in polytransfused thalassemic children, 43% (26/61) contracted HCV. We conclude that HCV infection may cause elevated ALT levels and portal fibrosis of the liver, whereas the viral titer and genotypes do not parallel ALT levels.

Genotyping of hepatitis C virus: coinfection by multiple genotypes detected in children with chronic posttransfusion hepatitis C

The distribution of genotypes of the hepatitis C virus (HCV) was studied in 24 children with chronic posttransfusion hepatitis C. Genotypes were determined by reverse transcription-nested polymerase chain reaction with type-specific primers. Twenty (83%) were infected by a single genotype: 14 by type II [1b], 3 by III [2a], and 3 IV [2b]. Four (17%) were coinfected by two genotypes. The amount of blood transfusion given to the patients infected by multiple genotypes was significantly larger than to those infected by a single genotype (mean +/- SD, 15.2 +/- 14.4 vs 78.6 +/- 42.0 U). Three of the four patients infected by multiple genotypes were considered to be immunocompromised by anticancer therapy for malignant disease. Eighteen patients showed a raised level of alanine aminotransferase throughout the follow-up, while the remaining six patients (three of type II [1b], two of IV [2b], and one of III [2a] + IV [2b]) achieved biochemical remission. Liver biopsy was performed on 19 patients. Compared to those with type III [2a] or IV [2b], those with type II [1b] appeared to show more severe histological changes with higher histological activity index scores, although there was no significant difference. The positive rates of antibody to C100-3 or 5-1-1 in patients with type III [2a] or IV [2b] were lower than in those with type II [1b] (33 and 33 vs 43 and 50%), whereas the antibody to C33C or C22-3 was detected in nearly all patients regardless of their genotypes. In the present study, we found a high incidence of multiple-genotype infection among children with chronic posttransfusion hepatitis C.

Prevalence, genotypes and antibody titer of hepatitis C virus in pregnant women in Taiwan

OBJECTIVES

To investigate the prevalence and genotypes of hepatitis C virus (HCV) in pregnant women in Taiwan, as well as to examine whether any correlation occurs between HCV genotype and anti-HCV titer.

METHODS

Forty-three pregnant women with positive anti-HCV and HCV-RNA were selected among 3,400 cases screened from January 1992 to March 1994. Each blood specimen was assayed for HCV genotypes by PCR method to detect HCV I, II, III and IV. Anti-HCV titer was determined by a second-generation EIA kit with serial dilutions.

RESULTS

Twenty-eight cases (65%) belonged to HCV II, 11 (26%) HCV III, 3 (7%) HCV IV and 1 (2%) HCV II+III. Besides, the anti-HCV titers in HCV II and HCV III groups were similar, ranging from 8x to 40,000x and revealing no statistical significance (p = 0.75).

CONCLUSIONS

Our data have verified that the prevalence rate of HCV infection in pregnant women is around 1.3% and no significant difference of anti-HCV titer occurs between HCV II and HCV III pregnant women.

Chronic viral hepatitis

Among hepatitis A to E viruses, hepatitis B, C, and D viruses can cause chronic hepatitis, in both children and adults. Hepatitis B virus (HBV) infection is the most prevalent and important one. Perinatal transmission accounts for about 40-45% of chronic HBV infection in hyperendemic areas. Horizontal transmission through intramuscular injection using non-sterile needles and intrafamilial spread accounts for the other half of carriers. During the natural course of HBV infection, the host gradually clears HBV and hepatitis B e antigen (HBeAg), liver damage and elevation of aminotransferases occur during the process of HBV clearance. The most effective way to eliminate HBV infection is immunoprophylaxis starting since birth. It can prevent both HBV and hepatitis D virus (HDV) infections. Hepatitis C virus (HCV) infection in children occurs mainly in high risk children, such as those who received blood product or injection using non-sterile needles, or infants of HCV viremic mothers, etc. Screening of blood product reduced markedly the prevalence of post-transfusion HCV infection, but the prevention of sporadic cases requires HCV vaccination which is still under investigation.