Hepatitis C virus genotype 6:Virology,epidemiology,genetic variation and clinical implication

Hepatitis C virus(HCV)is a serious public health problem affecting 170 million carriers worldwide.It is a leading cause of chronic hepatitis,cirrhosis,and liver cancer and is the primary cause for liver transplantation worldwide.HCV genotype 6(HCV-6)is restricted to South China,South-East Asia,and it is also occasionally found in migrant patients from endemic countries.HCV-6 has considerable genetic diversity with23 subtypes(a to w).Although direct sequencing followed by phylogenetic analysis is the gold standard for HCV-6 genotyping and subtyping,there are also now rapid genotyping tests available such as the reverse hybridization line probe assay(INNO-LiPAⅡ;Innogenetics,Zwijnaarde,Belgium).HCV-6 patients present with similar clinical manifestations as patients infected with other genotypes.Based on current evidence,the optimal treatment duration of HCV-6 with pegylated interferon/ribavirin should be 48 wk,although a shortened treatment duration of 24 wk could be sufficient in patients with low pretreatment viral load who achieve rapid virological response.In addition,the development of direct-acting antiviral agents is ongoing,and they give high response rate when combined with standard therapy.Herein,we review the epidemiology,classification,diagnosis and treatment as it pertain to HCV-6.

High prevalence of hepatitis B-antibody loss and a case report of de novo hepatitis B virus infection in a child after living-donor liver transplantation

AIM To assess the seroprevalence of hepatitis B virus(HBV) immunity among previously vaccinated pediatric liver transplant recipients and present a case report of de novo hepatitis B infection after liver transplantation.METHODS This study focused on children with chronic liver diseases who received primary hepatitis B immunization and had a complete dataset of anti-HBs before and after liver transplantation between May 2001 and June 2017. Medical records were retrospectively reviewed for potential factors relating to HBV immunity loss. RESULTS In total, 50 children were recruited. The mean time from liver transplantation to anti-HBs testing was 2.53 ± 2.11 years. The mean anti-HBs levels before and after liver transplantation were 584.41 ± 415.45 and 58.56 ± 6.40 IU/L, respectively. The rate of nonimmunity(anti-HBs < 10 IU/L) in the participants was 46%(n = 26) at one year, 57%(n = 7) at two years and 82%(n = 17) at > three years following liver transplantation. The potential factors relating to HBV immunity loss after liver transplantation were identified as anti-HBs(P = 0.002), serum albumin(P = 0.04), total bilirubin(P = 0.001) and direct bilirubin(P = 0.003) before liver transplantation. A five-year-old boy with biliary cirrhosis received 4 doses of HBV vaccine with an anti-HBs titer of > 1000 IU/L and underwent liver transplantation; his anti-HBc-negative father was the donor. After liver transplantation, the boy had stenosis of the hepatic artery up to the inferior vena cava anastomosis and underwent venoplasty three times. He also received subcutaneous injections of enoxaparin for 5 mo and 20 transfusions of blood components. Three years and ten months after the liver transplantation, transaminitis was detected with positive tests for HBs Ag, HBe Ag, and anti-HBc(2169.61, 1706 and 8.45, respectively; cutoff value: < 1.00) and an HBV viral load of 33212320 IU/mL.CONCLUSION The present study showed that loss of hepatitis B immunity after liver transplantation is unexpectedly common. In our case report, despite high levels of antiHBs prior to transplantation, infection occurred at a time when, unfortunately, the child had lost immunity to hepatitis B after liver transplantation.

Retinoic acid receptor beta promoter methylation and risk of cervical cancer

Cervical cancer is one of the leading causes of death in women worldwide, particularly in developing countries. Human papillomavirus has been reported as one of the key etiologic factors in cervical carcinoma. Likewise, epigenetic aberrations have ability to regulate cancer pathogenesis and progression. Recent research suggested that methylation has been detected already at precancerous stages, which methylation markers may have significant value in cervical cancer screening. The retinoic acid receptor beta (RARβ) gene, a potential tumor suppressor gene, is usually expressed in normal epithelial tissue. Methylation of CpG islands in the promoter region of the RARβ gene has been found to be associated with the development of cervical cancer. To investigate whether RARβ methylation is a potential biomarker that predicts the progression of invasive cancer, we reviewed 14 previously published articles related to RARβ methylation. The majority of them demonstrated that the frequency of RARβ promoter methylation was significantly correlated with the severity of cervical epithelium abnormalities. However, methylation of a single gene may not represent the best approach for predicting disease prognosis. Analyzing combinations of aberrant methylation of multiple genes may increase the sensitivity, and thus this approach may serve as a better tool for predicting disease prognosis.

Elevation of serum urokinase plasminogen activator receptor and liver stiffness in postoperative biliary atresia

AIM To investigate serum urokinase-type plasminogen activator receptor(u PAR) and liver stiffness in biliary atresia(BA) and examine the correlation of circulating u PAR, liver stiffness, and clinical outcomes in postoperative BA children.METHODS Eighty-five post Kasai BA children and 24 control subjects were registered. Circulating u PAR was measured using enzyme-linked immunosorbent essay. Liver stiffness was analyzed using transient elastography.RESULTS BA children had significantly greater circulating u PAR andliver stiffness scores than control subjects(P < 0.001). Circulating u PAR and liver stiffness were substantially higher in jaundiced BA children than non-jaundiced BA children(P < 0.001). In addition, circulating u PAR was positively associated with serum aspartate aminotransferase(r = 0.507, P < 0.001), alanine aminotransferase(r = 0.364, P < 0.001), total bilirubin(r = 0.559, P < 0.001), alkaline phosphatase(r = 0.325, P < 0.001), and liver stiffness scores(r = 0.508, P < 0.001).CONCLUSION Circulating u PAR and liver stiffness values were greater in BA children than healthy controls. The increased circulating u PAR was associated with liver dysfunction in BA. As a consequence, serum u PAR and liver stiffness may be used as noninvasive biomarkers indicating the progression of liver fibrosis in post Kasai BA.

Low bone mineral density and the severity of cholestasis in biliary atresia

AIM To investigate the prevalence of osteopenia and osteoporosis in postoperative biliary atresia(BA) children and the association of bone mineral density(BMD) and biochemical parameters in post Kasai BA subjects. METHODS A total of 70 patients with post Kasai BA were enrolled in this prospective study. The patients were classified into two groups according to their jaundice status. BMD of the lumbar spine was analyzed using dual energyX-ray absorptiometry.RESULTS The prevalence of low bone mass(osteopenia and osteoporosis) in BA patients were 51.4%(36 out of 70). Ten patients(35.7%) in the jaundice group and 8 patients(19.0%) in the non-jaundice group had osteopenia. Sixteen patients(57.1%) in the jaundice group and 2 patients(4.8%) in the no jaundice group had osteoporosis. In addition, lumbar spine BMD Z-score was substantially lower in the jaundice BA patients compared with non-jaundice patients. BA subjects with persistent jaundice had significantly lower serum 25-hydroxyvitamin D than those without jaundice. Further analysis revealed that lumbar spine BMD was correlated with age(r = 0.774, P < 0.001), serum albumin(r = 0.333, P = 0.005), total bilirubin(r =-0.476, P < 0.001), aspartate aminotransferase(r =-0.583, P < 0.001), alanine aminotransferase(r =-0.428, P < 0.001), and alkaline phosphatase(r =-0.456, P < 0.001).CONCLUSION Low BMD was associated with biochemical parameters reflecting the severity of cholestasis in post Kasai BA patients.

Molecular genome tracking of East,Central and South African genotype of Chikungunya virus in South-east Asia between 2006 and 2009

Objective:To understand the epidemiology of the East,Central and South African(ECSA) genotype of Chikungunya virus(CHIKV) in terms of emerging and re-emerging infections,this study has been aimed at investigating the evolutionary parameters,genomic signatures and molecular tracking of the CHIKV ECSA genotype in South-east Asia and coastal areas of the Indian Ocean between 2006 and 2009 by using phylogenetie analysis and the Bayesian Markov Chain Monte Carlo(BMCMC) evolutionary estimation.Methods:Nearly complete genome sequences of 53 CHIKV isolates from all genotypes were subjected to phylogenetie analysis and evolutionary parameter estimation.The amino acids of 67 of ECSA genotype during 2006 to 2009 were compared for finding molecular signature tracking.The ECSA genotype signatures were visualized to find the possible transmission root was projected onto a geographic map.Results: Phylogenetie analysis showed the ECSA genotype was divided into 2 groups.The first group comprises viruses from India and Southeast Asian countries.The second group consists of strains typically circulating in Sri Lanka in 2008.The evolutionary parameters of these groups depicted the time of the most recent common ancestor at approximately 7.5 years ago.The genomic signatures revealed the positions of amino acid variation in each group.Conclusions:The molecular evolution projected onto a geographical map showed the routes of CHIKV transmission from 2006 to 2009.Molecular tracking will assist in understanding transmission routes, epidemiology and molecular evolution of CHIKV.

Risk factors and molecular characterization of acute sporadic symptomatic hepatitis E virus infection in Thailand

Objective:To report clinical outcomes and viral genotypes of acute symptomatic hepatitis E virus(HEV)infection in Thailand.Methods:Forty patients with acute symptomatic HEV infection were recruited during 2009-2013.Clinical,demographic and laboratory data were collected.Diagnosis was accomplished by detection of anti-HEV IgM and/or HEV RNA in the serum or stool.HEV genotypes were classified by direct sequencing of RT-PCR products and phylogenetic analysis.Results:The high risk group,comprising immune-compromised,liver cirrhosis and very elderly(>80 years)patients(17 cases),had higher levels of serum alkaline phosphatase at presentation compared with the low risk group.Two fatal cases resulted from acute hepatitis E in the high risk group,initial clinical presentation did not show statistically significant differences.In six cases(6/40),the virus could be detected in serum or stool by RT-PCR and sequencing.Upon molecular characterization,the viruses were classified as HEV genotype 3f and were in the same cluster as Thai swine HEV.Conclusions:Our data showed that acute HEV infection has various clinical presentations and outcomes.Higher levels of serum alkaline phosphatase were observed in high risk patients.All isolated viruses were identified as HEV genotype 3f possibly originating from swine.

Increased osteopontin and liver stiffness measurement by transient elastography in biliary atresia

AIM: To analyze plasma osteopontin levels and liver stiffness using transient elastography in postoperative biliary atresia (BA) children compared with healthy controls. METHODS: Thirty children with postoperative BA and 10 normal controls were enrolled. The patients were categorized into two groups according to their jaundicestatus. Plasma levels of osteopontin were determined using commercially available enzyme-linked immunosorbent assay. Liver stiffness was measured by using transient elastography (Fibroscan). Ten validated Fibroscan measurements were performed in each patient and control with the result expressed in kilopascals (kPa). RESULTS: Plasma osteopontin was significantly elevated in BA children compared with that of healthy controls (47.0 ± 56.4 ng/mL vs 15.1 ± 15.0 ng/mL, P = 0.01). The liver stiffness measurement was markedly elevated in the patients with BA compared with that of controls (26.9 ± 24.6 kPa vs 3.9 ± 0.7 kPa, P = 0.001). Subgroup analysis showed that the BA patients with jaundice had more pronounced plasma osteopontin levels than those without jaundice (87.1 ± 61.6 ng/mL vs 11.9 ± 6.1 ng/mL, P = 0.001). Furthermore, the mean liver stiffness was significantly greater in the jaundiced BA patients compared with non-jaundiced patients (47.7 ± 21.8 kPa vs 8.7 ± 3.0 kPa, P = 0.001). Additionally, plasma osteopontin was positively related to serum total bilirubin (r = 0.64, P < 0.001). There was also a correlation between plasma osteopontin and liver stiffness values (r = 0.60, P < 0.001). CONCLUSION: High plasma osteopontin positively correlated with degree of hepatic fibrosis and could be used as a biochemical parameter reflecting disease severity in postoperative BA children.

Adiponectin as a novel biomarker for liver fibrosis

Adiponectin is known to play primary roles in the regulation of systemic glucose homeostasis and lipid metabolism. Interestingly, emerging evidence indicates beneficial effects of adiponectin on liver fibrosis; however, the exact mechanisms of this action remain unclear. Herein, we aimed to summarize the recent findings regarding the role of adiponectin in liver fibrogenesis and update the current comprehensive knowledge regarding usefulness of adiponectin-based treatments in liver fibrosis. Adiponectin has been demonstrated to have an anti-fibrotic action in the liver by blocking the activation of hepatic stellate cellmediated adenosine monophosphate-activated protein kinase and peroxisome proliferator-activated receptoralpha pathways, which in turn diminish the expression of pro-fibrotic genes. In addition, hyperadiponectinemia was noted in patients with various chronic liver diseases(CLDs)-related liver fibrosis. An increase in circulating adiponectin levels was also found to be associated with the development of liver fibrosis, indicating a role of adiponectin as a non-invasive biomarker for predicting the progression of liver fibrosis. It is therefore reasonable to speculate that adiponectin may be developed as a new therapeutic candidate for the treatment of liver fibrosis. Nonetheless, future observations are still necessary to fully elucidate the extent of the effects of adiponectin onliver fibrotic outcomes, in order to modify adiponectin as an anti-fibrotic therapy that would speed up fibrosis reversal in patients with CLD.

Multiplex real-time RT-PCR for detecting chikungunya virus and dengue virus

Objective:To develop diagnostic test for detection chikungunya virus(CHIKV and Dengue virus (DENV) infection.Methods:We have performed a rapid,accurate laboratory confirmative method to simultaneously detect,quantify and differentiate CHIKV and DENV infection by single-step multiplex real-time RT-PCR.Results:The assay’s sensitivity was 97.65%,specificity was 92.59% and accuracy was 95.82%when compared to conventional RT-PCR.Additionally,there was no cross-reaction between CHIKV,DENV,Japanese encephalitis virus,hepatitis C,hepatitis A or hepatitis E virus.Conclusions:This rapid and reliable assay provides a means for simultaneous early diagnosis of CHIKV and DENV in a single-step reaction.

Hepatitis E virus infection: Epidemiology and treatment implications

Hepatitis E virus(HEV) infection is now established as an emerging enteric viral hepatitis. Standard treatments in acute and chronic hepatitis E remain to be established. This study undertakes a review of the epidemiology, treatment implication and vaccine prevention from published literature. HEV infection is a worldwide public health problem and can cause acute and chronic hepatitis E. HEV genotypes 1 and 2 are primarily found in developing countries due to waterborne transmission, while the zoonotic potential of genotypes 3 and 4 affects mostly industrialized countries. An awareness of HEV transmission through blood donation, especially in the immunocompromised and solid organ transplant patients, merits an effective anti-viral therapy. There are currently no clear indications for the treatment of acute hepatitis E. Despite concerns for side effects, ribavirin monotherapy or in combination with pegylatedinterferon alpha for at least 3 mo appeared to show significant efficacy in the treatment of chronic hepatitis E. However, there are no available treatment options for specific patient population groups, such as women who are pregnant. Vaccination and screening of HEV in blood donors are currently a global priority in managing infection. New strategies for the treatment and control of hepatitis E are required for both acute and chronic infections, such as prophylactic use of medications, controlling large outbreaks, and finding acceptable antiviral therapy for pregnant women and other patient groups for whom the current options of treatment are not viable.

Immunization status and hospitalization for vaccine-preventable and non-vaccine-preventable infections in liver-transplanted children

BACKGROUND Infections and associated morbidity and mortality may be more frequent in children who have undergone liver transplant than in healthy children.Immunization strategies to prevent vaccine-preventable infections(VPIs)can effectively minimize this infection burden.However,data on age-appropriate immunization and VPIs in children after liver transplant in Asia are limited.AIM To evaluate the immunization status,VPIs and non-VPIs requiring hospitalization in children who have undergone a liver transplant.METHODS The medical records of children who had a liver transplant between 2004 and 2018 at King Chulalongkorn Memorial Hospital(Bangkok,Thailand)were retrospectively reviewed.Immunization status was evaluated via their vaccination books.Hospitalization for infections that occurred up to 5 years after liver transplantation were evaluated,and divided into VPIs and non-VPIs.Hospitalizations for cytomegalovirus and Epstein-Barr virus were excluded.Severity of infection,length of hospital stay,ventilator support,intensive care unit requirement,and mortality were assessed.RESULTS Seventy-seven children with a mean age of 3.29±4.17 years were included in the study,of whom 41(53.2%)were female.The mean follow-up duration was 3.68±1.45 years.Fortyeight children(62.3%)had vaccination records.There was a significant difference in the proportion of children with incomplete vaccination according to Thailand’s Expanded Program on Immunization(52.0%)and accelerated vaccine from Infectious Diseases Society of America(89.5%)(P<0.001).Post-liver transplant,47.9%of the children did not catch up with ageappropriate immunizations.There were 237 infections requiring hospitalization during the 5 years of follow-up.There were no significant differences in hospitalization for VPIs or non-VPIs in children with complete and incomplete immunizations.The risk of serious infection was high in the first year after receiving a liver transplant,and two children died.Respiratory and gastrointestinal systems were common sites of infection.The most common pathogens that caused VPIs were rotavirus,influenza virus,and varicella-zoster virus.CONCLUSION Incomplete immunization was common pre-and post-transplant,and nearly all children required hospitalization for non-VPIs or VPIs within 5 years posttransplant.Infection severity was high in the first year post-transplant.

Liver tumors in children with chronic liver diseases

Liver tumors are rare in children,but the incidence may increase in some circumstances and particularly in chronic liver diseases.Most liver tumors consequent to chronic liver diseases are malignant hepatocellular carcinoma.Other liver tumors include hepatoblastoma,focal nodular hyperplasia,adenoma,pseudotumor,and nodular regenerative hyperplasia.Screening of suspected cases is beneficial.Imaging and surrogate markers of alpha-fetoprotein are used initially as noninvasive tools for surveillance.However,liver biopsy for histopathology evaluation might be necessary for patients with inconclusive findings.Once the malignant liver tumor is detected in children with cirrhosis,liver transplantation is currently considered the preferred option and achieves favorable outcomes.Based on the current evidence,this review focuses on liver tumors with underlying chronic liver disease,their epidemiology,pathogenesis,early recognition,and effective management.

Early viral kinetics during hepatitis C virus genotype 6 treatment according to IL28B polymorphisms

AIM:To investigate the early viral kinetics and interleukin-28B(IL28B)polymorphisms of hepatitis C genotype6 during pegylated interferon and ribavirin therapy.METHODS:Sixty-five patients with chronic hepatitis C virus(HCV)infection treated with pegylated interferon and ribavirin(PEG-IFN/RBV)were included,of whom15(23.1%),16(24.6%)and 34(52.3%)patients were infected with hepatitis C genotype 1(HCV-1),genotype3(HCV-3)and genotype 6(HCV-6),respectively.Serum HCV-RNA levels were measured frequently during the first 4-wk of therapy.DNA extracted from samples was analyzed for the IL28B single nucleotide polymorphism(SNP)rs12979860 by polymerase chain reaction and direct sequencing.RESULTS:During the first 4-wk of therapy,the mean viral decline for patients with HCV-6(5.55±1.82 log10IU/mL)was comparable to that of patients with HCV-3(5.55±1.82 log10IU/mL vs 5.86±1.02 log10IU/mL,P=0.44)and was significantly higher than patients with HCV-1(5.55±1.82 log10IU/mL vs 4.23±1.99 log10IU/mL,P=0.04).In the HCV-6 group,the first phase(days 0-2)viral decline was significantly higher in patients with the favorable rs12979860 CC than non-CC genotypes(2.46±1.01 log10IU/mL/wk vs 1.70±0.67 log10IU/mL,respectively,P=0.045).A statistically insignificant decrease in the second-phase(days 7-28)decline was also found in patients with the CC genotype than those with the non-CC genotype,though not significantly different(1.24±0.64 log10IU/mL/wk vs 0.80±0.65 log10IU/mL/wk,respectively,P=0.172).At baseline,the SNP genotype was an independent predictor of rapid virological response but not of sustained virological response.CONCLUSION:The IL28B genotype was linked to an impact on early viral kinetics in response to PEG-IFN/RBV therapy in HCV-6 infected patients.

Eliminating viral hepatitis in children after liver transplants:How to reach the goal by 2030

Viral hepatitis infections are a great burden in children who have received liver transplant.Hepatotropic viruses can cause liver inflammation that can develop into liver graft fibrosis and cirrhosis over the long term.Immunological reactions due to viral hepatitis infections are associated with or can mimic graft rejection,rendering the condition difficult to manage.Prevention strategies using vaccinations are agreeable to patients,safe,cost-effective and practical.Hence,strategies to eliminate viral hepatitis A and B focus mainly on immunization programmes for children who have received a liver transplant.Although a vaccine has been developed to prevent hepatitis C and E viruses,its use is not licensed worldwide.Consequently,eliminating hepatitis C and E viruses mainly involves early detection in children with suspected cases and effective treatment with antiviral therapy.Good hygiene and sanitation are also important to prevent hepatitis A and E infections.Donor blood products and liver grafts should be screened for hepatitis B,C and E in children who are undergoing liver transplantation.Future research on early detection of viral hepatitis infections should include molecular techniques for detecting hepatitis B and E.Moreover,novel antiviral drugs for eradicating viral hepatitis that are highly effective and safe are needed for children who have undergone liver transplantation.

Strategies to Prevent Mother-to-child Transmission of Hepatitis B Virus

Mother-to-child transmission(MTCT)of hepatitis B virus(HBV)is the primary cause of chronic HBV infection worldwide.MTCT prevention and antiviral treatment of infected individuals could eliminate this public health burden.Antiviral treatment of hepatitis B surface antigen(HBsAg)-positive pregnant women and immunoprophylaxis with HBV vaccine and hepatitis B immune globulin are the most effective strategies to interfere with MTCT of HBV.However,for worldwide application of those strategies,feasibility,availability,cost,safety,and effectiveness should be considered.Cesarean section and breastfeeding avoidance in hepatitis B e antigenpositive mothers with a high viral load and without antiviral therapy during pregnancy could be an option,but more supporting evidence is needed.HBsAg screening of all pregnant women is recommended when initiating antiviral therapy and immunoprophylaxis for MTCT prevention,except in areas with limited resources.Timely HBV vaccination series administered soon after birth might be the mainstay of prevention.This review aimed to provide a concise update on the effectiveness of available strategies to prevent MTCT of HBV.