Association between severity of type A hepatitis and nucleotide variations in the 5' non-translated region of hepatitis A virus RNA: strains from fulminant hepatitis have fewer nucleotide substitutions

Recent advances in hepatitis A virus research and clinical practice guidelines for hepatitis A virus infection in Japan

In 2018, there was a hepatitis A outbreak in Japan, and hepatitis A virus (HAV) infection is considered a sexually transmitted disease. In general, patients with hepatitis A should be given attention, and this disease should be prevented more than ever. The Japan Agency for Medical Research and Development (AMED) Hepatitis A and E viruses (HAV and HEV) Study Group has worked on the project to create "Recent Advances in Hepatitis A Virus (HAV) Research and Clinical Practice Guidelines for HAV Infection in Japan". The group consists of expert hepatologists and virologists who gathered at virtual meeting on August 5, 2023. Data about the pathogenesis, infection routes, diagnosis, complications, several factors for the severities, vaccination, and current and future treatments for hepatitis A were discussed and debated for a draft version. The participants assessed the quality of cited studies. The finalized recommendations are presented in this review. The recent advances in HAV research and clinical practice for HAV infection in Japan, have been reviewed by the AMED HAV and HEV Study Group.

Hepatitis A virus infection

Hepatitis A is a vaccine-preventable infection caused by the hepatitis A virus (HAV). Over 150 million new infections of hepatitis A occur annually. HAV causes an acute inflammatory reaction in the liver that usually resolves spontaneously without chronic sequelae. However, up to 20% of patients experience a prolonged or relapsed course and <1% experience acute liver failure. Host factors, such as immunological status, age, pregnancy and underlying hepatic diseases, can affect the severity of disease. Anti-HAV IgG antibodies produced in response to HAV infection persist for life and protect against re-infection; vaccine-induced antibodies against hepatitis A confer long-term protection. The WHO recommends vaccination for individuals at higher risk of infection and/or severe disease in countries with very low and low hepatitis A virus endemicity, and universal childhood vaccination in intermediate endemicity countries. To date, >25 countries worldwide have implemented such programmes, resulting in a reduction in the incidence of HAV infection. Improving hygiene and sanitation, rapid identification of outbreaks and fast and accurate intervention in outbreak control are essential to reducing HAV transmission.

Etiology of viral induced acute liver failure and defensins as potential therapeutic agents in ALF treatment

Acute liver failure (ALF) is a rare and severe disease, which, despite continuous advances in medicine, is still characterized by high mortality (65-85%). Very often, a liver transplant is the only effective treatment for ALF. Despite the implementation of prophylactic vaccinations in the world, the viral background of ALF is still a problem and leads to many deaths. Depending on the cause of ALF, it is sometimes possible to reverse this condition with appropriate therapies, which is why the search for effective antiviral agents seems to be a very desirable direction of research. Defensins, which are our natural antimicrobial peptides, have a very high potential to be used as therapeutic agents for infectious liver diseases. Previous studies on the expression of human defensins have shown that increased expression of human α and β-defensins in HCV and HBV infections is associated with a better response to treatment. Unfortunately, conducting clinical trials for ALF is very difficult due to the severity of the disease and the low incidence, therefore animal models are important for the development of new therapeutic strategies. One of the best animal models that has real reference to research on acute liver failure (ALF) is rabbit hemorrhagic disease in rabbits caused by the Lagovirus europaeus virus. So far, there have been no studies on the potential of defensins in rabbits infected with Lagovirus europaeus virus.

Fulminant Hepatitis A and E Co-infection Leading to Acute Liver Failure: A Case Report

Acute liver failure (ALF) is a severe clinical condition with a high mortality rate. Although several factors can cause ALF, viral hepatitis remains one of the leading causes. Hepatitis A virus (HAV) and hepatitis E virus (HEV), which typically cause self-limiting acute disease, are rare but emerging causes of ALF, especially when both viruses infect the same individual. Both of these hepatotropic viruses share an enteric route and are most commonly transmitted through the fecal-oral route. The impact of HAV/HEV co-infection on acute hepatitis prognosis is not entirely understood, but dual infection can further exacerbate liver damage, leading to fulminant hepatic failure (FHF) with a higher mortality rate than a single virus infection. Here, we present a case of a 32-year-old male with no prior liver disease who presented to the emergency department with a two-week history of jaundice, abdominal pain, and hepatomegaly. Upon admission, he was disoriented with grade 2 encephalopathy. After a thorough investigation, co-infection with hepatitis A and E was identified as the primary cause of his ALF. The patient underwent intensive medical treatment and interventions, including dialysis. Unfortunately, the patient's survival was not possible due to the absence of availability of a transplanted organ, which is currently the only definitive treatment option. This case report underscores the significance of prompt diagnosis, timely intervention, and the accessibility of transplantation in the survival of liver failure, as it remains the sole definitive treatment for acute liver failure. Moreover, it provides a concise overview of the current literature on fulminant co-infection of HAV and HEV, including epidemiology, clinical characteristics, pathogenesis, diagnosis, treatment, and risk factors associated with co-infection of hepatitis A and E and their role in causing ALF. It also highlights the significance of identifying high-risk populations and implementing appropriate prevention and control measures such as vaccination, practising good hygiene and sanitation, and avoiding the consumption of contaminated food and water.

Thirty-two years' experience of treating fulminant hepatitis in a Japanese single center

AIM

The prognosis of patients with acute liver failure has improved dramatically in the past three decades due to advances in medical critical care and use of liver transplantation (LT) in Western countries, where the etiology of acute liver failure is different from that in Japan. We analyzed patients with fulminant hepatitis (FH) and late-onset hepatic failure (LOHF) admitted to our unit over a 32-year period to clarify the nature of Japanese patients with FH and LOHF.

METHODS

A total of 137 Japanese patients with FH and LOHF between 1986 and 2017 were analyzed for etiologies, disease types, treatment protocols, and outcome.

RESULTS

Of 137 patients, 124 were FH (53 acute type and 71 subacute type) and 13 LOHF. The major etiology was due to viral infections in 48% of patients. A total of 23.4% of patients recovered without LT, 7.3% received LT, and 69.3% died without LT. The number of patients showed rise and fall without an evident decrease during the period. Patients with autoimmune hepatitis increased after the establishment of autoimmune hepatitis criteria in 1999 (p < 0.001), and that with indeterminate cause decreased (p < 0.01). The mean age was older in the last decade than in the first decade (p = 0.036). Spontaneous and overall survival rates were not different during the period.

CONCLUSIONS

The prognosis of our patients with FH and LOHF has not improved, probably because of aging and the increasing proportion of etiologies with poor prognosis and difficult-to-treat patients without response to medications regardless of advancement of clinical management, including artificial liver support devices and LT.

Acute Liver Failure due to Hepatitis A Virus

Acute liver failure (ALF) is a syndrome, rather than a specific disease, with several possible causes, and viral hepatitis is a major cause. The relationship between self-limited and ALF hepatitis A is still poorly understood. A 45-year-old woman presented to our hospital with ALF diagnosis (from another hospital). She suffered from hospital-acquired pneumonia. The patient recovered within 4 weeks and returned to her normal life after 6 months of follow-up.

Pathogenicity and virulence of hepatitis A virus

Hepatitis A is an acute infection of the liver, which is mostly asymptomatic in children and increases the severity with age. Although in most patients the infection resolves completely, in a few of them it may follow a prolonged or relapsed course or even a fulminant form. The reason for these different outcomes is unknown, but it is generally accepted that host factors such as the immunological status, age and the occurrence of underlaying hepatic diseases are the main determinants of the severity. However, it cannot be ruled out that some virus traits may also contribute to the severe clinical outcomes. In this review, we will analyze which genetic determinants of the virus may determine virulence, in the context of a paradigmatic virus in terms of its genomic, molecular, replicative, and evolutionary features.

Artificial intelligence and machine learning could support drug development for hepatitis A virus internal ribosomal entry sites

Hepatitis A virus (HAV) infection is still an important health issue worldwide. Although several effective HAV vaccines are available, it is difficult to perform universal vaccination in certain countries. Therefore, it may be better to develop antivirals against HAV for the prevention of severe hepatitis A. We found that several drugs potentially inhibit HAV internal ribosomal entry site-dependent translation and HAV replication. Artificial intelligence and machine learning could also support screening of anti-HAV drugs, using drug repositioning and drug rescue approaches.

Polyvalent Human Immune Globulin: A Prospective, Open-Label Study Assessing Anti-Hepatitis A Virus (HAV) Antibody Levels, Pharmacokinetics, and Safety in HAV-Seronegative Healthy Subjects

Background

Analytical data suggesting that immunoglobulin given intramuscularly (IGIM) may have reduced protection against hepatitis A virus (HAV) infection led to an update in the recommended IGIM dose (0.2 ml/kg).

Methods

This prospective, open-label, single-arm clinical study evaluated whether a single 0.2 ml/kg dose of IGIM provided protective levels of anti-HAV antibodies (≥ 10 mIU/ml for up to 60 days) in HAV-seronegative healthy adults.

Results

Of the 28 subjects enrolled and dosed, 26 (93%) completed the study. Mean uncorrected anti-HAV antibody titers peaked at 109 mIU/ml on day 5 and stayed above 10 mIU/ml through day 60 (N = 26). The mean uncorrected anti-HAV antibody titers had a median T_max of 95.33 h, a mean C_max of 118 mIU/ml, and a mean observed T_half of 63.3 days; baseline-corrected titers had a median T_max of 95.33 h, a mean C_max of 114 mIU/ml, and a mean observed T_half of 47.1 days (N = 27). All subjects (28/28) experienced at least 1 treatment-emergent adverse event (TEAE), with a total of 83 TEAEs reported; none was serious, and 96% (80/83) resolved without sequelae. Most (63%) events judged definitely and possibly related to study treatment involved localized pain due to intramuscular injections. There were no serious adverse events and no deaths or discontinuations due to TEAEs.

Conclusions

A single 0.2 ml/kg dose of IGIM provided protective anti-HAV levels for at least 60 days, with acceptable safety and tolerability profiles in healthy subjects. Uncorrected and baseline-corrected pharmacokinetic findings were similar and consistent with the corresponding sampling points in previous research.

Trial Registration

ClinicalTrials.gov Identifier, NCT03351933.

Characteristics of acute hepatitis A virus infection before and after 2001: A hospital-based study in Tokyo, Japan

BACKGROUND AND AIM

The incidence of acute hepatitis A [AH (A)] is decreasing because of improvements in hygiene; however, cases of sporadic severe hepatitis are still being reported. We assessed the epidemiology of AH (A) in Japan.

METHODS

This was a hospital-based retrospective study, in which 126 AH (A) patients (96 men [76%], median age 39 [range, 19-66] years) were enrolled. Patients diagnosed with AH (A) before 2001 (n = 79) and after 2001 (n = 47) were compared.

RESULTS

The incidence of AH (A) showed peaks in 1990, 1999, and 2018. After 2001, one patient had hepatitis B virus, four had human immunodeficiency virus, and three had syphilis coinfections. Before and after 2001, HAV was transmitted, respectively, by raw oysters (28% and 26%), overseas travel (19% and 28%), and sexual contact (0% and 19%) (P < 0.01). The frequencies of symptoms were appetite loss (51% and 32%), fever (63% and 81%), and diarrhea (3% and 13%) (all P < 0.05), respectively. On admission, the median levels of alanine aminotransferase (1455 and 3069 U/L) and γ-glutamyl transpeptidase (221 and 345 U/L) were significantly higher (P < 0.01), and the prothrombin time (77.5% and 65.9%) and platelet count (22.7 and 16.4 × 10/μL) were significantly lower after 2001 (P < 0.05). A time to normalization of the bilirubin level ≥ 30 days was associated with older age and a diagnosis of AH (A) after 2001.

CONCLUSIONS

Outbreaks and severe AH (A) cases due to sexual transmission have been reported recently. It is necessary to examine their sexual behavior and other sexual infection.

Emerging hepatitis E virus compared with hepatitis A virus: A new sanitary challenge

Hepatitis A (HAV) and E (HEV) viruses are able to cause liver disease in humans. Among the five classical hepatotropic viruses, they are mainly transmitted via the fecal-oral route. Historically, many similarities have thus been described between them according to their incidence and their pathogenicity, especially in countries with poor sanitary conditions. However, recent advances have provided new insights, and the gap is widening between them. Indeed, while HAV infection incidence tends to decrease in developed countries along with public health improvement, HEV is currently considered as an underdiagnosed emerging pathogen. HEV autochthonous infections are increasingly observed and are mainly associated with zoonotic transmissions. Extra hepatic signs resulting in neurological or renal impairments have also been reported for HEV, as well as a chronic carrier state in immunocompromised patients, arguing in favor of differential pathogenesis between those two viruses. Recent molecular tools have allowed studies of viral genome variability and investigation of links between viral plasticity and clinical evolution. The identification of key functional mutations in viral genomes may improve the knowledge of their clinical impact and is analyzed in depth in the present review.

A Model to Predict 1-Month Risk of Transplant or Death in Hepatitis A-Related Acute Liver Failure

Acute liver failure (ALF) caused by hepatitis A is a rare but fatal disease. Here, we developed a model to predict outcome in patients with ALF caused by hepatitis A. The derivation set consisted of 294 patients diagnosed with hepatitis A-related ALF (ALFA) from Korea, and a validation set of 56 patients from Japan, India, and United Kingdom. Using a multivariate proportional hazard model, a risk-prediction model (ALFA score) consisting of age, international normalized ratio, bilirubin, ammonia, creatinine, and hemoglobin levels acquired on the day of ALF diagnosis was developed. The ALFA score showed the highest discrimination in the prediction of liver transplant or death at 1 month (c-statistic, 0.87; 95% confidence interval [CI], 0.84-0.92) versus King's College criteria (KCC; c-statistic, 0.56; 95% CI, 0.53-0.59), U.S. Acute Liver Failure Study Group index specific for hepatitis A virus (HAV-ALFSG; c-statistic, 0.70; 95% CI, 0.65-0.76), the new ALFSG index (c-statistic, 0.79; 95% CI, 0.74-0.84), Model for End-Stage Liver Disease (MELD; c-statistic, 0.79; 95% CI, 0.74-0.84), and MELD including sodium (MELD-Na; c-statistic, 0.78; 95% CI, 0.73-0.84) in the derivation set (all P < 0.01). In the validation set, the performance of the ALFA score (c-statistic, 0.84; 95% CI, 0.74-0.94) was significantly better than that of KCC (c-statistic, 0.65; 95% CI, 0.52-0.79), MELD (c-statistic, 0.74; 95% CI, 0.61-0.87), and MELD-Na (c-statistic, 0.72; 95% CI, 0.58-0.85) (all P < 0.05), and better, but not statistically significant, than that of the HAV-ALFSG (c-statistic, 0.76; 95% CI, 0.61-0.90; P = 0.28) and new ALFSG indices (c-statistic, 0.79; 95% CI, 0.65-0.93; P = 0.41). The model was well-calibrated in both sets. Conclusion: Our disease-specific score provides refined prediction of outcome in patients with ALF caused by hepatitis A.

Comparative Pathology of Hepatitis A Virus and Hepatitis E Virus Infection

Hepatitis A virus (HAV) and hepatitis E virus (HEV) cause acute, self-limiting hepatic infections that are usually spread by the fecal-oral route in humans. Naturally occurring and experimental infections are possible in a variety of nonhuman primates and, in the case of HEV, a number of other species. Many advances in understanding the pathogenesis of these viruses have come from studies in experimental animals. In general, animals infected with these viruses recapitulate the histologic lesions seen in infected humans, but typically with less severe clinical and histopathological manifestations. This review describes the histopathologic changes associated with HAV and HEV infection in humans and experimental animals.

High recovery rate of consciousness by high-volume filtrate hemodiafiltration for fulminant hepatitis

AIM

An artificial liver support (ALS) system sustaining patients with acute liver failure (ALF) in good condition until recovery of the native liver or performance of liver transplantation (LT), is essential for the improvement of the poor prognosis of ALF despite the lack of survival benefit. We aimed to investigate the efficacy of various ALS systems for fulminant hepatitis (FH) carried out in our liver unit so far, focusing on the restoration of consciousness from hepatic encephalopathy.

METHODS

One hundred and ten consecutive adult Japanese patients with FH admitted to Chiba University Hospital (Chiba, Japan) between 1988 and 2016 who received ALS were analyzed.

RESULTS

Recovery rate of consciousness improved with the increased dialysate flow rate and filtrate rate: 37.5% by plasma exchange (PE), 51.9% by PE + continuous hemodiafiltration (CHDF), 57.7% by slow PE (sPE) + high-flow CHDF (HFCHDF) (Q_D  = 300 mL/min), 88.6% by HFCHDF (Q_D  = 500 mL/min) (+ sPE), and 92.9% by on-line HDF (OLHDF) (+ sPE). All patients except one, who could not be fully treated because of circulatory failure, recovered consciousness by OLHDF, including those whose liver function were completely abolished. Superiority of HFCHDF (Q_D  = 500 mL/min) and OLHDF was also shown in patients who died without LT or received LT.

CONCLUSIONS

More effective ALS should be recognized considering the extremely high recovery rate of consciousness. In particular, OLHDF with predilution reduces the cost of substitution fluid by supplying an unlimited amount of dialysate as substitution fluid prepared using an on-line system, and simplifies the procedure for the management.

Natural History, Clinical Manifestations, and Pathogenesis of Hepatitis A

Hepatitis A virus (HAV) is transmitted by the fecal-oral route and is a major cause of acute viral hepatitis. The clinical manifestations of HAV infection range from asymptomatic infection to acute liver failure (ALF), but do not include progression to chronic hepatitis. Risk factors for severe acute hepatitis A are older age (>40 years) and preexisting liver disease. Some patients may show atypical clinical features such as relapsing hepatitis, prolonged cholestasis, or extrahepatic manifestations. Almost all hepatitis A patients spontaneously recover with supportive care. However, in the case of ALF (<1%), intensive care and urgent decision on liver transplantation are required. Liver injury during hepatitis A is not directly caused by HAV but is known to be caused by immune-mediated mechanisms. In this review, the natural history and clinical manifestations of hepatitis A are described. In addition, mechanisms of immunopathogenesis in hepatitis A are discussed.

Viral Hepatitis and Acute Liver Failure: Still a Problem

Although the overall prevalence is on the decline, viral hepatitis still plays a major role in the development of acute liver failure (ALF) worldwide. Hepatitis A, B, D, and E contribute to most fulminant viral courses. These viruses have not gained much attention in recent years yet remain relevant from a clinical perspective as the incidence in certain populations is on the increase. Other viral therapies and immunotherapies are currently being examined as treatments for hepatitis D and hepatitis E. Clinicians should still maintain a high index of suspicion for viral causes in approaching patients with ALF.

Fatal acute hepatic failure in a family infected with the hepatitis A virus subgenotype IB: A case report

RATIONALE

Hepatitis A viral infection is a well-known cause of subclinical or acute self-limited hepatitis. Few cases of hepatitis A virus (HAV)-associated acute liver failure (ALF) have been reported in low HAV endemic countries annually.

PATIENTS CONCERNS

To investigate the possible factors that affected the severity of HAV infection, a family cluster infected with the HAV subgenotype IB strain, which is not common in Japan, was described.

DIAGNOSES

This family consisted of five members who all were infected with HAV.

INTERVENTIONS

Four of the five patients hospitalized except for an asymptomatic patient.

OUTCOMES

Two of the five patients, men in their 50s and 60s, developed ALF, and one patient died. Various host factors, including sex (male), age, and a high bilirubin level, may affect the outcomes. Based on viral factors, HAV RNA was higher in the fatal case compared with others, and it decreased within a short period of time. The similarity of the nucleotide sequences was 99.9% among the HAV isolates based on an entire genomic sequence. Deletions and/or insertions on the HAV protein-coding sequences that caused a frameshift were found in surviving cases but not in the fatal case.

LESSONS

The rapid clearance of increased HAV and the absence of defective HAV might be closely associated with the onset of liver failure.

Deep sequencing in the management of hepatitis virus infections

The hepatitis viruses represent a major public health problem worldwide. Procedures for characterization of the genomic composition of their populations, accurate diagnosis, identification of multiple infections, and information on inhibitor-escape mutants for treatment decisions are needed. Deep sequencing methodologies are extremely useful for these viruses since they replicate as complex and dynamic quasispecies swarms whose complexity and mutant composition are biologically relevant traits. Population complexity is a major challenge for disease prevention and control, but also an opportunity to distinguish among related but phenotypically distinct variants that might anticipate disease progression and treatment outcome. Detailed characterization of mutant spectra should permit choosing better treatment options, given the increasing number of new antiviral inhibitors available. In the present review we briefly summarize our experience on the use of deep sequencing for the management of hepatitis virus infections, particularly for hepatitis B and C viruses, and outline some possible new applications of deep sequencing for these important human pathogens.

Liver Failure due to Acute Viral Hepatitis (A-E)

BACKGROUND

Viral hepatitis is still one of the key causes of acute liver failure (ALF) in the world.

METHODS

A selective literature search of the PubMed database was conducted, including current studies, reviews, meta-analyses, and guidelines. We obtained an overview of ALF due to viral hepatitis in terms of epidemiology, course, and treatment options.

RESULTS

Most fulminant viral courses are reported after infection with hepatitis A, B, and B/D, but not with hepatitis C. Hepatitis E is also known to cause ALF but has not gained much attention in recent years. However, more and more autochthonous hepatitis E virus infections have been recently observed in Europe. Reactivation of hepatitis B virus (HBV) under immunosuppressive conditions, such as after intensive chemotherapy, is also an increasing problem. For most viral-induced cases of ALF, liver transplantation represented the only therapeutic option in the past. Today, immediate treatment of HBV-induced ALF with nucleotide or nucleoside analogs is well tolerated and beneficially affects the course of the disease.

CONCLUSION

Although numbers in Western European countries are decreasing rapidly, reliable diagnostic screening for hepatitis A-E is necessary to identify the etiology and to determine those most at risk of developing ALF.

Importance of the poor prognosis of severe and fulminant hepatitis in the elderly in an era of a highly aging society: Analysis in a Japanese center

AIM

Older age has been widely believed to be associated with a poor prognosis of acute liver failure. We aimed to evaluate the impact of older age on outcomes of Japanese patients with severe and fulminant hepatitis in an era of a highly aging society.

METHODS

We investigated 105 consecutive adult patients with fulminant hepatitis (FH) or severe hepatitis (SH) admitted to our liver unit between 2000 and 2013, consisting of 14 elderly patients (≥65 years) and 91 younger ones (<65 years).

RESULTS

In elderly patients, the proportion of women was greater (P < 0.001), the levels of aspartate aminotransferase and lactate dehydrogenase on admission were lower (P = 0.011 and P = 0.010, respectively), and the survival rate without liver transplantation was lower (P = 0.024) than younger ones. Two of seven SH and all seven FH elderly patients died, whereas all 45 SH and 16 of 46 FH younger patients recovered. Seventy-one percent of elderly patients had underlying diseases with medications, and 57% had additional complications after the start of treatment for acute liver failure. Patients aged 70 years or more showed even poorer prognoses than younger ones and those aged 65-69 years (P = 0.0052 and P = 0.036, respectively).

CONCLUSION

Older age was associated with a poor prognosis of patients with SH and FH. One of the reasons other than complications and loss of organ reserve by aging would be that elderly patients consulted us at a more advanced stage of illness than younger ones.

Clinical Factors and Viral Load Influencing Severity of Acute Hepatitis A

Background and Aims

Clinical manifestations of hepatitis A virus (HAV) infection vary from mild to fulminant hepatic failure (FHF) in adults. We investigated the relationship between laboratory findings, including viral load, and clinical outcomes in patients with acute hepatitis A (AHA) and evaluated predictive factors for severe acute hepatitis (s-AH).

Methods

We analyzed the clinical manifestations of AHA in 770 patients. Patients with a prothrombin time (PT) of less than 40% of normal were classified as s-AH and included 4 patients with FHF, 11 patients with acute renal failure, and 3 patients with prolonged jaundice (n = 128). Other patients were defined as mild acute hepatitis (m-AH) (n = 642). Serum samples were obtained from 48 patients with acute hepatitis A. Among them, 20 with s-AH, and 28 with m-AH, were tested for HAV RNA titer.

Results

In a multivariate analysis, age (HR = 1.042, P = 0.041), peak creatinine (HR = 4.014, P = 0.001), bilirubin (HR = 1.153, P = 0.003), alanine aminotransferase (ALT) (HR = 1.001, P<0.001), initial lactate dehydrogenase (LDH) (HR = 1.000, P = 0.045) and total cholesterol (HR = 0.978, P<0.001) were independent factors for s-AH. Serum HAV RNA was detected in 20/20 (100%) patients with s-AH and 22/28 (78.6%) patients with m-AH. In a multivariate analysis of the 48 patients who were tested for HAV RNA, peak ALT (HR = 1.001, P = 0.004) and HAV RNA titer (HR = 2.076, P = 0.012) were independent factors for s-AH.

Conclusions

Clinical factors including age, peak creatinine, bilirubin, ALT, initial LDH and total cholesterol were independent factors for s-AH in a multivariate analysis. In particular, HAV load strongly correlated with the severity of hepatitis A.

Molecular epidemiology of hepatitis A virus infection in Northeast India

The present study was undertaken to screen the molecular epidemiology of Hepatitis A virus (HAV) in Northeast India (NEI) who are ethnically distinct, tribal dominated and of lower socio-economic status with almost no information available from NEI on these aspects. Briefly, 3 ml blood was collected from 324 random liver disease cases with jaundice, receiving care at Central Hospital, N.F. Railway, Guwahati, Assam with informed consent. The patients detected with HAV-IgM positive status were included and were stratified as acute viral hepatitis (AVH) and fulminant hepatitis (FHF) based on clinical profile. Viral RNA was isolated and HAV-RNA was detected by Real-time PCR using primers for the VP3-VP1 region. HAV genotyping was studied by PCR-direct sequencing-phylogenetic analysis approach using the VP1/2A region of HAV isolates. Statistical analysis was performed using SPSS13.0 software. A total of 69 cases were HAV infected with two HBV co-infected cases (n = 69 + 2 = 71), 62 cases and two co-infected cases were AVH and others were FHF cases. HAV infection was predominant in especially in the young and adult age group. HAV-RNA was detected in 28 cases, out of which 19 cases could be genotyped (12 AVH, 7 FHF); which showed the prevalence of genotype IIIA or IA only. Although HAV genotype IIIA was the major genotype in both the AVH (10/12, 83.33%) and FHF (5/7, 71.43%) group, but the difference in distribution of genotypes in AVH and FHF cases was statistically non-significant (P = 0.550). HAV genotype IIIA is associated with the majority of HAV infected cases and severity in NEI.

Ultra-deep sequencing analysis of the hepatitis A virus 5'-untranslated region among cases of the same outbreak from a single source

Hepatitis A virus (HAV) is a causative agent of acute viral hepatitis for which an effective vaccine has been developed. Here we describe ultra-deep pyrosequences (UDPSs) of HAV 5'-untranslated region (5'UTR) among cases of the same outbreak, which arose from a single source, associated with a revolving sushi bar. We determined the reference sequence from HAV-derived clone from an attendant by the Sanger method. Sixteen UDPSs from this outbreak and one from another sporadic case were compared with this reference. Nucleotide errors yielded a UDPS error rate of < 1%. This study confirmed that nucleotide substitutions of this region are transition mutations in outbreak cases, that insertion was observed only in non-severe cases, and that these nucleotide substitutions were different from those of the sporadic case. Analysis of UDPSs detected low-prevalence HAV variations in 5'UTR, but no specific mutations associated with severity in these outbreak cases. To our surprise, HAV strains in this outbreak conserved HAV IRES sequence even if we performed analysis of UDPSs. UDPS analysis of HAV 5'UTR gave us no association between the disease severity of hepatitis A and HAV 5'UTR substitutions. It might be more interesting to perform ultra-deep sequencing of full length HAV genome in order to reveal possible unknown genomic determinants associated with disease severity. Further studies will be needed.

Hepatitis A virus: host interactions, molecular epidemiology and evolution

Infection with hepatitis A virus (HAV) is the commonest viral cause of liver disease and presents an important public health problem worldwide. Several unique HAV properties and molecular mechanisms of its interaction with host were recently discovered and should aid in clarifying the pathogenesis of hepatitis A. Genetic characterization of HAV strains have resulted in the identification of different genotypes and subtypes, which exhibit a characteristic worldwide distribution. Shifts in HAV endemicity occurring in different parts of the world, introduction of genetically diverse strains from geographically distant regions, genotype displacement observed in some countries and population expansion detected in the last decades of the 20th century using phylogenetic analysis are important factors contributing to the complex dynamics of HAV infections worldwide. Strong selection pressures, some of which, like usage of deoptimized codons, are unique to HAV, limit genetic variability of the virus. Analysis of subgenomic regions has been proven useful for outbreak investigations. However, sharing short sequences among epidemiologically unrelated strains indicates that specific identification of HAV strains for molecular surveillance can be achieved only using whole-genome sequences. Here, we present up-to-date information on the HAV molecular epidemiology and evolution, and highlight the most relevant features of the HAV-host interactions.

Genotypic shift of the hepatitis A virus and its clinical impact on acute hepatitis A in Korea: a nationwide multicenter study

BACKGROUND

The genotypic shift of hepatitis A virus (HAV) and its correlation with clinical course has not been evaluated in acute hepatitis A (AHA).

METHODS

From June 2007 to May 2009, we prospectively enrolled 546 AHA patients. We performed a nested reverse transcriptase polymerase chain reaction (RT-PCR) using the serum samples in addition to phylogenetic analysis, then we compared patient clinical features.

RESULTS

Among 351 successfully genotyped patients, we found genotype IIIA in 178 patients (51%) and IA in 173 patients (49%). The sequences of genotype IA are identical to previously reported Korean genotype IA, and the new IIIA genotype is closely related to NOR24/Norway. We retrospectively analyzed 41 AHA samples collected from 2000 to 2006 and found that all of them were genotype IA. Patients with genotype IIIA showed significantly higher levels of aspartate aminotransferase, higher levels of alanine aminotransferase, and lower platelet counts than patients with genotype IA when comparing baseline laboratory data or peak/lowest laboratory data during the disease course. However, there were no differences in duration of hospital stay, incidence of cholestatic hepatitis, acute kidney injury, and acute liver failure, or mortality between them.

CONCLUSIONS

A genotypic shift of the HAV was identified in Korean AHA subjects, and genotype IIIA HAV has become endemic. Although there were significant differences in the biochemical responses of AHA between genotype IA and genotype IIIA patients, we did not detect any differences in clinical outcomes such as complications or mortality.

Determination of the full-genome sequence of hepatitis E virus (HEV) SAAS-FX17 and use as a reference to identify putative HEV genotype 4 virulence determinants

Background

Four major genotypes of hepatitis E virus (HEV), the causative agent of hepatitis E, have so far been recognized. While genotypes 3 and 4 are both zoonotic, the disease symptoms caused by the latter tend to be more severe. To examine if specific nucleotide/amino acid variations between genotypes 3 and 4 play a role in determining the severity of hepatitis E disease, the complete genome of one swine HEV genotype 4 isolate, SAAS-FX17, was determined and compared with other genotype 4 and genotype 3 genomes to identify putative HEV genotype 4 virulence determinants.

Results

A total of 42 conformable nt/aa variations between genotype 3 and 4 HEVs were detected, of which 19 were proposed to be potential disease severity determinants for genotype 4 strains.

Conclusions

One potential determinant was located in each of the 5'-UTR and 3'-UTR, 3 and 12 within ORF1 and ORF2 respectively, and 2 in the junction region.

Laboratory diagnosis of hepatitis A

The diagnostic gold standard for hepatitis A is the detection of anti-hepatitis A virus (HAV) IgM antibodies and the determination of total anti-HAV by enzyme immunoassay. However, detection of HAV RNA can be useful in the diagnosis of patients without specific antibodies for hepatitis A and for the monitoring of infection. Studies using real-time PCR have demonstrated that HAV RNA can be detected not only in feces, but also in serum and saliva samples earlier than detection of antibodies, and that viremia may be present for a much longer period than the convalescent phase of hepatitis A. Alternative samples have been proposed for diagnosis, epidemiological studies, investigation of outbreaks and selection of persons receptive to vaccination. Understanding the events of clinical course that take place during the hepatitis A infection may lead to more effective diagnosis.

Clinical features and outcomes of acute kidney injury among patients with acute hepatitis A

BACKGROUND

Although acute hepatitis A is usually self-limited, the clinical manifestations can vary from mild to severe liver dysfunction. However, little is known about risk factors for and outcomes of acute kidney injury (AKI) in acute hepatitis A.

OBJECTIVES

To identify the risk factors for and outcomes of AKI in acute hepatitis A.

STUDY DESIGN

We identified 396 patients with acute hepatitis A, which registered between January 2006 and June 2009 at a tertiary care university hospital. Retrospective case-control studies were conducted in order to identify risk factors for AKI.

RESULTS

Thirty patients (7.6%) developed AKI. On multivariate analysis, fulminant hepatitis, leukocytosis, and elevated CRP were independent risk factors for AKI associated with hepatitis A, and higher total bilirubin, leukocytosis, and elevated CRP were independent risk factor for AKI within nonfulminant hepatitis A. Of the 30 patients with AKI, 23 (76.7%) patients fully recovered, 2 patients maintained hemodialysis after hospital discharge and 5 patients died due to hepatic failure without recovery from AKI. Among 20 patients with AKI in nonfulminant subgroup, 19 patients (95%) recovered without hemodialysis.

CONCLUSIONS

AKI is not a rare complication of acute hepatitis A and severity of hepatitis and hepatic injury influence the development of AKI in acute hepatitis A.

Clinical features of re-emerging hepatitis A: an analysis of patients hospitalized during an urban epidemic in Korea

From April 2008 to November 2008, many cases of hepatitis A were reported in Seoul and Gyeonggi Province in Korea. Furthermore, the rate of severe or fulminant hepatitis have significantly increased during the latest epidemic (13.4% vs. 5.2%, p=0.044). Therefore, widespread use of vaccine is warranted to reduce the burden of hepatitis A in Korea.

What factors determine the severity of hepatitis A-related acute liver failure?

The reason(s) that hepatitis A virus (HAV) infection may progress infrequently to acute liver failure are poorly understood. We examined host and viral factors in 29 consecutive adult patients with HAV-associated acute liver failure enrolled at 10 sites participating in the US ALF Study Group. Eighteen of twenty-four acute liver failure sera were PCR positive while six had no detectable virus. HAV genotype was determined using phylogenetic analysis and the full-length genome sequences of the HAV from a cute liver failure sera were compared to those from self-limited acute HAV cases selected from the CDC database. We found that rates of nucleotide substitution did not vary significantly between the liver failure and non-liver failure cases and there was no significant variation in amino acid sequences between the two groups. Four of 18 HAV isolates were sub-genotype IB, acquired from the same study site over a 3.5-year period. Sub-genotype IB was found more frequently among acute liver failure cases compared to the non-liver failure cases (chi-square test, P < 0.01). At another centre, a mother and her son presented with HAV and liver failure within 1 month of each other. Predictors of spontaneous survival included detectable serum HAV RNA, while age, gender, HAV genotype and nucleotide substitutions were not associated with outcome. The more frequent appearance of rapid viral clearance and its association with poor outcomes in acute liver failure as well as the finding of familial cases imply a possible host genetic predisposition that contributes to a fulminant course. Recurrent cases of the rare sub-genotype IB over several years at a single centre imply a community reservoir of infection and possible increased pathogenicity of certain infrequent viral genotypes.

Scientific Opinion on an update on the present knowledge on the occurrence and control of foodborne viruses

A review of the biology, epidemiology, diagnosis and public health importance of foodborne viruses was performed. Data needs to support a risk assessment were also identified. In addition possible control options and their anticipated impact to prevent or reduce the number of foodborne viral human infections were identified, including the scientific reasons for and against the establishment of food safety criteria and process hygiene criteria for viruses for certain food categories. Food may be contaminated by virus during all stages of the food supply chain, and transmission can occur by consumption of food contaminated during the production process (primary production, or during further processing), or contaminated by infected food handlers. Transmission of zoonotic viruses (e.g. HEV) can also occur by consumption of products of animal origin. Viruses do not multiply in foods, but may persist for extended periods of time as infectious particles in the environment, or in foods. At the EU-level it is unknown how much viral disease can be attributed to foodborne spread. The relative contribution of different sources (shellfish, fresh produce, food handler including asymptomatic shedders, food handling environment) to foodborne illness has not been determined. The Panel recommends focusing controls on preventive measures to avoid viral contamination rather than trying to remove/inactivate these viruses from food. Also, it is recommended to introduce a microbiological criteria for viruses in bivalve molluscs, unless they are labelled "to be cooked before consumption". The criteria could be used by food business operators to validate their control options. Furthermore, it is recommended to refine the regulatory standards and monitoring approaches in order to improve public health protection. Introduction of virus microbiological criteria for classification of bivalve molluscs production areas should be considered. A virus monitoring programme for compliance with these criteria should be risk based according to the findings of a sanitary survey.

Hepatitis A viral load in relation to severity of the infection

A correlation between hepatitis A virus (HAV) genomes and the clinical severity of hepatitis A has not been established. The viral load in sera of hepatitis A patients was examined to determine the possible association between hepatitis A severity and HAV replication. One hundred sixty-four serum samples from 91 Japanese patients with sporadic hepatitis A, comprising 11 patients with fulminant hepatitis, 10 with severe acute hepatitis, and 70 with self-limited acute hepatitis, were tested for HAV RNA. The sera included 83 serial samples from 20 patients. Viral load was measured by real-time RT-PCR. The detection rates of HAV RNA from fulminant, severe acute, and acute hepatitis were 10/11 (91%), 10/10 (100%), and 55/70 (79%), respectively. Mean values of HAV RNA at admission were 3.48 ± 1.30 logcopies/ml in fulminant, 4.19 ± 1.03 in severe acute, and 2.65 ± 1.64 in acute hepatitis. Patients with severe infection such as fulminant hepatitis and severe acute hepatitis had higher initial viral load than patients with less severe infection (P < 0.001). Viremia persisted for 14.2 ± 5.8 days in patients with severe infection and 21.4 ± 10.6 days in those with acute hepatitis after clinical onset (P = 0.19). HAV RNA was detectable quantitatively in the majority of the sera of hepatitis A cases during the early convalescent phase by real-time PCR. Higher initial viral replication was found in severely infected patients. An excessive host immune response might follow, reducing the viral load rapidly as a result of the destruction of large numbers of HAV-infected hepatocytes, and in turn severe disease might be induced.

A polymorphism in TIM1 is associated with susceptibility to severe hepatitis A virus infection in humans

During infection with the hepatitis A virus (HAV), most patients develop mild or asymptomatic disease. However, a small number of patients develop serious, life-threatening hepatitis. We investigated this variability in disease severity by examining 30 Argentinean patients with HAV-induced acute liver failure in a case-control, cross-sectional, observational study. We found that HAV-induced severe liver disease was associated with a 6-amino-acid insertion in TIM1/HAVCR1 (157insMTTTVP), the gene encoding the HAV receptor. This polymorphism was previously shown to be associated with protection against asthma and allergic diseases and with HIV progression. In binding assays, the TIM-1 protein containing the 157insMTTTVP insertion polymorphism bound HAV more efficiently. When expressed by human natural killer T (NKT) cells, this long form resulted in greater NKT cell cytolytic activity against HAV-infected liver cells, compared with the shorter TIM-1 protein without the polymorphism. To our knowledge, the 157insMTTTVP polymorphism in TIM1 is the first genetic susceptibility factor shown to predispose to HAV-induced acute liver failure. Furthermore, these results suggest that HAV infection has driven the natural selection of shorter forms of the TIM-1 protein, which binds HAV less efficiently, thereby protecting against severe HAV-induced disease, but which may predispose toward inflammation associated with asthma and allergy.

Analysing complete genome sequence of swine hepatitis E virus (HEV), strain CHN-XJ-SW13 isolated from Xinjiang, China: putative host range, and disease severity determinants in HEV

Hepatitis E is a worldwide public health problem, particular in areas where hygiene conditions are poor. Hepatitis E virus (HEV) has at least four genotypes: genotypes 1 and 2 exclusively infect human; while genotypes 3 and 4, are considered to be a zoonotic agent, infecting both humans and animals. This study was aimed at determining why genotype 3 and 4 HEV strains isolated from swine are able to cross species borders, whereas genotype1 and 2 strains isolated from humans are not. The full length genome of the swine HEV isolate CHN-XJ-SW13 was amplified as overlapping fragments using reverse-transcription-nested polymerase chain reaction (RT-nPCR) and rapid amplification of cDNA ends (RACE). The sequence of CHN-XJ-SW13 was compared with those of 90 HEV strains covering genotype 1-4 retrieved from GenBank. Possible regions of the viral genome, specifying the host range of HEV or associated with the severity of hepatitis E disease, were then screened for with the aid of the ALIGNX sequences alignment software package. The CHN-XJ-SW13 swine HEV isolate was determined to be a novel subtype of genotype 4, whose sequence provided several valuable clues for tracing the sources of human HEV infection. 25 specific nucleotide positions were identified to possibly being involved specifying the host range of HEV or determining the severity of hepatitis E disease.

Analysis of 5' nontranslated region of hepatitis A viral RNA genotype I from South Korea: comparison with disease severities

The aim of the study was to analyze genotype I hepatitis A virus (HAV) 5' nontranslated region (NTR) sequences from a recent outbreak in South Korea and compare them with reported sequences from Japan. We collected a total of 54 acute hepatitis A patients' sera from HAV genotype I [27 severe disease (prothrombin time INR ≥ 1.50) and 27 mild hepatitis (prothrombin time INR <1.00)], performed nested RT-PCR of 5' NTR of HAV directly sequenced from PCR products (∼ 300 bp), and compared them with each other. We could detect HAV 5'NTR sequences in 19 of the 54 (35.1%) cases [12 of 27 severe cases (44.4%) and 7 of 27 self-limited cases (25.9%)], all of which were subgenotype IA. Sequence analysis revealed that sequences of severe disease had 93.6%-99.0% homology and of self-limited disease 94.3%-98.6% homology, compared to subgenotype IA HAV GBM wild-type IA sequence. In this study, confirmation of the 5'NTR sequence differences between severe disease and mild disease was not carried out. Comparison with Japanese HAV A10 revealed (222)C to G or T substitution in 8/12 cases of severe disease and (222)C to G or T and (392)G to A substitutions in 5/7 and 4/7 cases of mild disease, respectively, although the nucleotide sequences in this study showed high homology (93.6%-100%). In conclusion, HAV 5'NTR subgenotype IA from Korea had relatively high homology to Japanese sequences previously reported from Japan, and this region would be considered one of the antiviral targets. Further studies will be needed.

Nucleotide variability and translation efficiency of the 5' untranslated region of hepatitis A virus: update from clinical isolates associated with mild and severe hepatitis

Mutations in the internal ribosome entry site (IRES) of hepatitis A virus (HAV) have been associated with enhanced in vitro replication and viral attenuation in animal models. To address the possible role of IRES variability in clinical presentation, IRES sequences were obtained from HAV isolates associated with benign (n = 8) or severe (n = 4) hepatitis. IRES activity was assessed using a bicistronic dual-luciferase expression system in adenocarcinoma (HeLa) and hepatoma (HuH7) cell lines. Activity was higher in HuH7 than in HeLa cells, except for an infrequently isolated genotype IIA strain. Though globally low, significant variation in IRES-dependent translation efficiency was observed between field isolates, reflecting the low but significant genetic variability of this region (94.2% +/- 0.5% nucleotide identity). No mutation was exclusive of benign or severe hepatitis, and variations in IRES activity were not associated with a clinical phenotype, indirectly supporting the preponderance of host factors in determining the clinical presentation.

Clinical implications of hepatitis A virus ribonucleic acid detection and genotyping in acute liver failure in children in Argentina

OBJECTIVES

To investigate the detection of hepatitis A virus ribonucleic acid in patients with acute liver failure and to assess if the results have any clinical implications for the evolution of acute liver failure in children. Hepatitis A infection, a vaccine-preventable disease, is an important cause of acute liver failure in children in Argentina. Universal vaccination in 1-yr-old children was implemented in June 2005.

DESIGN

Observational study in which patients were divided into Group 1 consisting of positive hepatitis A virus ribonucleic acid and Group 2 consisting of negative hepatitis A virus ribonucleic acid.

SETTING

Pediatric intensive care unit in National Pediatric Hospital "Dr. J. P. Garrahan," Buenos Aires, Argentina.

PATIENTS

Thirty-three patients with the diagnosis of acute liver failure secondary to hepatitis A virus infection and admitted to the Garrahan Pediatric Hospital between September 2003 and September 2005 were enrolled in the study. Twenty of these children were admitted to the pediatric intensive care unit.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Samples for total ribonucleic acid detection and genotyping were obtained from serum and/or stools on admission. We found positive hepatitis A virus ribonucleic acid in 13 patients and negative hepatitis A virus ribonucleic acid in 20 patients. The following clinical variables were evaluated: time of evolution, hospital stay, admission to the pediatric intensive care unit, pediatric intensive care unit stay, time on mechanical ventilation, criteria for orthotopic liver transplantation, and mortality. Characterization of the isolates did not reveal differences related to genotype; all cases were IA. No statistical significance was found as to the variables. However, positive hepatitis A virus ribonucleic acid showed lower percentages of pediatric intensive care unit admissions, criteria for orthotopic liver transplantation, number of orthotopic liver transplantation, and mortality than the group of patients with negative hepatitis A virus ribonucleic acid.

CONCLUSIONS

Hepatitis A virus genotyping studies did not show any particularities, all cases were IA and, thus, apparent associations between genotype and the clinical presentation of acute liver failure could not be found.

Internal ribosomal entry-site activities of clinical isolate-derived hepatitis A virus and inhibitory effects of amantadine

AIM

Little is known about specific naturally-occurring internal ribosomal entry site (IRES) activities of hepatitis A virus (HAV). We examined these activities using the bicistronic reporter assay and the effects of antiviral amantadine against their activities.

METHODS

Six HAV IRES clones from three patients with fulminant hepatitis and three with self-limited acute hepatitis were obtained. The activities of their IRES were analyzed using bicistronic reporter assay in hepatocyte- and non-hepatocyte-derived cell lines, and the potential efficaciousness of the amantadine was examined.

RESULTS

One clone from fulminant hepatitis had a deletion in domains III-IV of HAV IRES had higher IRES activities than HM175 in HLE and Huh-7 cells. In Huh-7 cells, amantadine is effective for inhibiting HAV IRES activities, and especially fulminant hepatitis-derived ones.

CONCLUSION

HAV IRES derived from clinical isolates have various activities. Bicistronic reporter assay using clinical isolates may be another useful tool for testing antiviral activities like those of amantadine and the new acridines and hydrazones recently reported.

Molecular epidemiology of hepatitis A virus in the South-East area of Gyeonggi-do in Korea

PURPOSE

Hepatitis A virus (HAV) has been a leading cause of acute hepatitis in Korea. The reported genotypes of acute hepatitis A in Korea are the subgenotype IA and IB. The aim of the present study is to investigate HAV genotypes in the south-east area of Gyeonggi-do in Korea.

MATERIALS AND METHODS

From June 2004 to June 2006, 46 acute hepatitis A patients were enrolled prospectively. All had sporadic acute hepatitis A patients. All suspected cases of acute hepatitis A were tested for IgM anti-HAV antibodies. We sequenced 168 bp of nucleotides of the putative VP1/P2A junction and determined the HAV genotype with reverse transcriptase polymerase chain reaction. The clinical and laboratory results of all patients were recorded.

RESULTS

HAV-ribonucleic acid (RNA) was detected in 41 samples out of 46 samples. Among the 41 samples, 25 (60%) were shown to have subgenotype IIIA and the other 16 (40%) were subgenotype IA. Several amino acid substitutions were found.

CONCLUSION

In these HAV sporadic cases, IIIA and IA were identified, and this may reflect co-circulation of various genotypes in Korea. This study provides valuable new data on the genetic distribution of HAV and important information to help design appropriate public health measures.

Phylogenetic analysis of hepatitis A virus in sera from patients with hepatitis A of various severities

BACKGROUND

We analysed the association of the 5' nontranslated region (5'NTR), nonstructural proteins 2B and 2C of the hepatitis A virus (HAV) genome, whose mutations have previously been shown to be important for enhanced replication in cell culture systems, in order to align all our data and examine whether genomic differences in HAV are responsible for the range of clinical severities.

METHODS

Our accumulated HAV strains of 5'NTR [nucleotide(nt) 200 and 500], entire 2B and 2C from 25 Japanese patients with sporadic hepatitis A, consisting of seven patients with fulminant hepatitis (FH), five with severe acute hepatitis (AHs) and 13 with self-limited acute hepatitis (AH), in whom the sequences of all three regions were available, were subjected to phylogenetic analysis.

RESULTS

Fulminant hepatitis patients had fewer nucleotide substitutions in 5'NTR, had a tendency to have more amino acid (aa) substitutions in 2B and had fewer aa substitutions in 2C than AH patients. Four FH and two AHs with a higher viral replication were located in the near parts of the phylogenetic trees, indicating the association between the severity of hepatitis A and genomic variations in 5'NTR, 2B and 2C of HAV.

CONCLUSIONS

Our study suggests that genetic variations in HAV not in one specific region but in 5'NTR, 2B and 2C might cooperatively influence replication of the virus, and thereby affect virulence. Viral factors should be considered and examined when discussing the mechanisms responsible for the severity of hepatitis A.

HBV superinfection in HCV chronic carriers: a disease that is frequently severe but associated with the eradication of HCV

The impact of hepatitis B virus (HBV) superinfection in hepatitis C virus (HCV) chronic carriers was evaluated in a long-term follow-up study on 29 chronic anti-HCV carriers with acute hepatitis B (AVH-B) (Case group BC) and 29 anti-HCV negative patients with AVH-B (Control group B), pair-matched for age (+/-5 years), sex, and risk factors for the acquisition of HBV infection. Patients in Case group BC and those in Control group B showed similar initial HBV viral load and a similar trend of becoming negative for HBV-DNA. AVH-B showed a severe course more frequently in Case group BC than in Control group B (34.5% versus 6.9%, P < 0.05). Of the 28 patients in Case group BC alive at the end of the acute illness (one death from liver failure), 24 were followed up for 2-6 years, median 5 years: 22 patients became HBsAg-negative and two progressed to HBsAg-positive chronic hepatitis. HCV-RNA was undetectable in all patients during AVH-B; in the 24 patients with a long-term follow-up, HCV-RNA was detected in seven (29.2%) after 1 year, in 14 (58.3%) after 2 years, and in 18 (75%) after 3-6 years. The six patients who eradicated chronic HCV infection, compared with 18 showing reactivation of HCV replication, had higher values of aspartate aminotransferase and alanine aminotransferase and a higher prevalence of cases with severe AVH-B (83.3% versus 22.2%, P < 0.05).

CONCLUSIONS

Although it can be life-threatening, HBV superinfection in HCV chronic carriers may lead to clearance of chronic HCV infection, especially in patients with severe AVH-B.

Initial thrombocytopenia as a simple, valuable predictor for clinical manifestation in acute hepatitis A

OBJECTIVE

Although acute hepatitis A (AH-A) is usually self-limited, the clinical manifestations can vary from mild to severe liver dysfunction. However, little is known about the simple, valuable predictors for clinical manifestation in AH-A. The objective of this study was to identify the simple clinical predictors for severe liver dysfunction and its clinical course.

MATERIAL AND METHODS

A total of 162 IgM anti-hepatitis A virus (HAV) positive patients were enrolled in the study. Severe AH-A was defined as a prothrombin time <40% of control activity. Various liver-unrelated and liver-related parameters at presentation were compared separately between the severe AH-A group and the non-severe group.

RESULTS

Mean age (+/-SD) was 27.5 (+/-7.1) years and the proportion of males was 54% (88/162). Fourteen patients (8.7%) experienced severe AH-A. Of the liver-unrelated parameters, leukopenia (<4000/microl), thrombocytopenia (<150,000/microl), and high serum C-reactive protein levels (>8 mg/l) at presentation were significant predictors for severe AH-A in a univariate analysis (p<0.05). On multivariate analysis, only thrombocytopenia was an independent predictor for severe AH-A (odds ratio (OR) 5.562, 95% confidence interval (CI) 1.153-26.834, p=0.033). Of the liver-related parameters, there were no independent predictors, as shown by multivariate analysis. The thrombocytopenia group (33%, 54/162) not only had a longer recovery time (28 days (range, 14-140) versus 37 days (20-128), p<0.001), but also more frequent complications (OR 4.632, 95% CI 1.886-11.372, p=0.001) than the non-thrombocytopenia group.

CONCLUSIONS

Initial thrombocytopenia may be a simple, valuable predictor for severity and clinical course in AH-A.

Analysis of hepatitis A virus protein 2B in sera of hepatitis A of various severities

BACKGROUND

In our recent study of the full-length hepatitis A virus (HAV) genome from some patients with fulminant hepatitis and acute hepatitis, possible associations were suggested between the severity of hepatitis A and the amino acid substitutions in the nonstructural protein 2B. We therefore analyzed HAV 2B from many patients with various clinical disease severities.

METHODS

Serum samples from 30 Japanese patients with sporadic hepatitis A from five widely separated regions of Japan, comprising nine patients with fulminant hepatitis (FH), six with severe acute hepatitis (AHs), and 15 with acute hepatitis (AH), were examined for HAV RNA. The entire sequences of HAV 2B were analyzed.

RESULTS

Compared with the sequence of the wild-type HAV strain GBM, nucleotide sequences of 2B had homology of 94.5 +/- 1.0% in FH, 95.2 +/- 1.2% in AHs, and 95.1 +/- 1.8% in AH. Deduced amino acid sequences had homology of 97.5 +/- 2.1% in FH, 97.9 +/- 2.4% in AHs, and 98.5 +/- 1.3% in AH. Differences were not statistically significant among the three groups. The average number of amino acid mutations between amino acids 100 and 200 was 5.0 +/- 5.2 per case in FH, 4.0 +/- 6.0 in AHs, and 1.9 +/- 2.9 in AH. The differences between FH and AH, AHs and AH, and between severe cases (FH and AHs) and nonsevere cases (AH) were not statistically significant (P = 0.13, P = 0.45, and P = 0.10, respectively).

CONCLUSIONS

There were no obvious differences in the sequences among FH, AHs, and AH throughout the 2B region, but there seemed to be more mutations in the strains obtained from FH and AHs patients than in those obtained from AH patients in the central part of HAV 2B.

Acute Hepatitis with Severe Cholestasis and Prolonged Clinical Course Due to Hepatitis A Virus Ia and Ib Coinfection

BACKGROUND

Acute viral hepatitis due to hepatitis A virus is a self-limited illness that infrequently has a severe clinical course.

METHODS

We analyzed the virological characteristics of acute hepatitis A in a patient with a severe clinical presentation (peak total and conjugated bilirubin levels, 65.5 mg/dL and 40.1 mg/dL, respectively) and a course of disease that lasted 7 months.

RESULTS

Hepatitis A virus sequencing revealed coinfection with 2 subgenotypes of hepatitis A virus (Ia and Ib) as etiological factors of the illness.

CONCLUSIONS

Hepatitis A virus Ia and Ib coinfection may have accounted for the prolonged and severe course of illness.