T. Jake Liang

A hepatitis B virus mutant associated with an epidemic of fulminant hepatitis

BACKGROUND A nosocomial outbreak of fulminant hepatitis B occurred in five patients in Haifa, Israel. Previous investigations identified the suspected source as a carrier of hepatitis B surface antigen who was positive for antibodies to hepatitis B e antigen and had chronic liver disease. We examined the strain of hepatitis B virus (HBV) that caused this epidemic, in order to identify specific mutations in the precore or core region. METHODS The presence of HBV was identified by polymerase-chain-reaction amplification of viral DNA in serum from the source patient, the five patients with fulminant hepatitis B, and five controls with acute, self-limited hepatitis B. The amplified viral HBV DNA samples were then cloned and sequenced. RESULTS Sequence analysis of viral DNA established that the same HBV mutant with two mutations in the precore region was present in the source patient and the five patients with fulminant hepatic failure. This HBV mutant had significant sequence divergence from other known HBV subtypes in the X, precore, and core regions. Cloned HBV DNA derived from a hospitalized patient who had subclinical hepatitis B at the same time as the outbreak and from four other control subjects with acute, self-limited hepatitis B all contained the wild-type sequence in the precore region. CONCLUSIONS In the outbreak we studied, a mutant hepatitis B viral strain was transmitted from a common source to five patients who subsequently died of fulminant hepatitis B infection. Naturally occurring viral mutations hepatitis B infection. Naturally occurring viral mutations in the HBV genome may predispose the infected host to more severe liver injury.

Fulminant or subfulminant non-A, non-B viral hepatitis: The role of hepatitis C and E viruses

BACKGROUND Although non-A, non-B (NANB) viral hepatitis has been implicated as an etiology of fulminant hepatitis, hepatitis C virus (HCV) has not been shown to result in acute hepatic failure and hepatitis E virus (HEV) has predominantly been associated with fulminant hepatitis among pregnant women. METHODS Using polymerase chain reaction to detect HCV and HEV genomes, four-antigen radioimmunoblot assay (4-RIBA) to measure anti-HCV antibodies, and enzyme-linked immunosorbent assay (ELISA) to detect anti-HEV immunoglobulin M (IgM) antibodies, 17 patients with sporadic fulminant or subfulminant hepatitis of presumed NANB viral etiology were studied. RESULTS The diagnosis of acute NANB viral hepatitis was made based on clinical information, serological tests, biochemical profiles, and pathological features. All 17 patients were negative for anti-HEV IgM antibodies and HEV RNA in either serum and/or liver. HCV RNAs were detected in 2 patients although anti-HCV antibodies were negative in all of them. CONCLUSIONS It is shown that HCV is infrequently associated with and HEV is not an identifiable cause of presumed NANB fulminant or subfulminant hepatitis in this patient population. Although further studies will be required for identification of the causative agent, it is possible that another agent is responsible for the occurrence of sporadic NANB fulminant or subfulminant hepatitis.

Association of IL28B genotype with fibrosis progression and clinical outcomes in patients with chronic hepatitis C: A longitudinal analysis

Interleukin (IL)28B polymorphisms are associated with spontaneous clearance of hepatitis C virus (HCV) infection and response to therapy. Whether IL28B genotype affects fibrosis progression or clinical outcome is unclear. Our aim was to study the relationship between IL28B genotype and both histological and clinical outcomes in patients with chronic hepatitis C (CHC). Hepatic fibrosis was scored using the Ishak (0‐6) scale; progression was defined as a 2‐point increase in Ishak score between biopsies. Multiple logistic and Cox regressions were used to identify variables associated with fibrosis progression. In all, 1,483 patients were included in a baseline cross‐sectional analysis, from which 276 were eligible for a paired biopsy analysis (median time between biopsies 4 years), and 400 for a clinical outcome analysis. At baseline biopsy, patients with IL28B CC genotype had significantly higher portal inflammation (2.4 versus 2.2) and alanine aminotransferase (ALT) levels (133 versus 105 U/L; P < 0.05 for all). In the paired biopsy analysis, there was no difference in the frequency of fibrosis progression between patients with IL28B CC and non‐CC genotypes (17% versus 23%). In logistic regression, only higher baseline alkaline phosphatase, lower platelets, and greater hepatic steatosis were associated with fibrosis progression. Patients with IL28B CC were twice as likely to develop adverse clinical outcomes compared to non‐CC (32% versus 16%; P = 0.007). Conclusion: IL28B CC genotype was associated with greater hepatic necroinflammation, higher ALT, and worse clinical outcomes in CHC patients. This suggests that IL28B CC is associated with a state of enhanced immunity that, on the one hand, can promote viral clearance, but alternately can increase necroinflammation and hepatic decompensation without enhancing fibrosis progression. (Hepatology 2013;58:1548–1557)

Association of hepatitis B viral precore mutations with fulminant hepatitis B in Japan

We studied the precore DNA sequences of hepatitis B viral genomes in five patients with fulminant hepatitis B and in five with acute self-limited hepatitis B from Japan. Using the polymerase chain reaction, three to four independent HBV DNA clones from each patient were obtained and analyzed. We demonstrated that patients with fulminant hepatitis B carried HBV genomes with a G to A mutation at nucleotide positions 1898 (five of five patients; 18 of 18 clones, 100%) and 1901 (five of five patients; 12 of 18 clones, 66%) in the precore region. The first mutation results in an in-phase stop codon (TAG) in the precore open reading frame and the absence of HBeAg production. In contrast, a G to A mutation was found in 6 of 16 clones (37%) in position 1898 and in 0 of 16 clones (0%) in position 1901 from patients with acute self-limited hepatitis. We concluded that both of the precore mutations are commonly associated with fulminant hepatitis B and may contribute to the pathogenesis of fulminant hepatitis. A hypothetical model for the biological significance of these two mutations is proposed.

Experimental models of hepatitis B and C — new insights and progress

Viral hepatitis is a major cause of morbidity and mortality, affecting hundreds of millions of people worldwide. Hepatitis-causing viruses initiate disease by establishing both acute and chronic infections, and several of these viruses are specifically associated with the development of hepatocellular carcinoma. Consequently, intense research efforts have been focusing on increasing our understanding of hepatitis virus biology and on improving antiviral therapy and vaccination strategies. Although valuable information on viral hepatitis emerged from careful epidemiological studies on sporadic outbreaks in humans, experimental models using cell culture, rodent and non-human primates were essential in advancing the field. Through the use of these experimental models, improvement in both the treatment and prevention of viral hepatitis has progressed rapidly; however, agents of viral hepatitis are still among the most common pathogens infecting humans. In this Review, we describe the important part that these experimental models have played in the study of viral hepatitis and led to monumental advances in our understanding and treatment of these pathogens. Ongoing developments in experimental models are also described.

AASLD clinical practice guidelines: A critical review of scientific evidence and evolving recommendations: Hepatology

The American Association for the Study of Liver Diseases (AASLD) practice guidelines provide recommendations in diagnosing and managing patients with liver disease from available scientific evidence in combination with expert consensus opinions. The aim was to systematically review the evolution of recommendations from AASLD guidelines and identify gaps limiting the evidence‐based foundations of these guidelines. Initial and current AASLD guidelines published from January 1998 to August 2012 were reviewed. The AGREE II instrument was used to evaluate rigor and transparency of guideline development. The number of recommendations, distribution of grades (strength or certainty), classes (benefit versus risk), and types of recommendations were evaluated. Whenever possible, multiple versions were evaluated for evolving scientific evidence. A total of 991 recommendations from 28 guidelines on 17 topics were evaluated. From initial to current guidelines, the total number of recommendations increased by 36% (512 to 699). The largest increases were from chronic hepatitis B virus (HBV) (+71), liver transplantation (+53), and autoimmune hepatitis (AIH) (+27). Most current recommendations are grade II (44%) and less than 20% are grade I. The AGREE II evaluation showed global improvement in guideline quality. Both HBV and chronic hepatitis C guidelines had greatest increases in grade I recommendations (+383% and +67%, respectively). The greatest increases in treatment recommendations were from HBV (grade I, +1,150%), liver transplantation (grade II, +112%), and AIH (grade III, +105%). Conclusion: Despite significant increases in the numbers of recommendations within AASLD practice guidelines over time, only a minority are supported by grade I evidence, highlighting the need for developing well‐designed investigations to provide evidence for areas of uncertainty and improving the quality of future guidelines in hepatobiliary diseases. (Hepatology 2013; 58:2142–2152)

The AASLD Clinical Practice Guidelines: A Critical Review of Scientific Evidence and Evolving Recommendations

The American Association for the Study of Liver Diseases (AASLD) practice guidelines provide recommendations in diagnosing and managing patients with liver disease from available scientific evidence in combination with expert consensus opinions. The aim was to systematically review the evolution of recommendations from AASLD guidelines and identify gaps limiting the evidence‐based foundations of these guidelines. Initial and current AASLD guidelines published from January 1998 to August 2012 were reviewed. The AGREE II instrument was used to evaluate rigor and transparency of guideline development. The number of recommendations, distribution of grades (strength or certainty), classes (benefit versus risk), and types of recommendations were evaluated. Whenever possible, multiple versions were evaluated for evolving scientific evidence. A total of 991 recommendations from 28 guidelines on 17 topics were evaluated. From initial to current guidelines, the total number of recommendations increased by 36% (512 to 699). The largest increases were from chronic hepatitis B virus (HBV) (+71), liver transplantation (+53), and autoimmune hepatitis (AIH) (+27). Most current recommendations are grade II (44%) and less than 20% are grade I. The AGREE II evaluation showed global improvement in guideline quality. Both HBV and chronic hepatitis C guidelines had greatest increases in grade I recommendations (+383% and +67%, respectively). The greatest increases in treatment recommendations were from HBV (grade I, +1,150%), liver transplantation (grade II, +112%), and AIH (grade III, +105%). Conclusion: Despite significant increases in the numbers of recommendations within AASLD practice guidelines over time, only a minority are supported by grade I evidence, highlighting the need for developing well‐designed investigations to provide evidence for areas of uncertainty and improving the quality of future guidelines in hepatobiliary diseases. (Hepatology 2013; 58:2142–2152)

Baseline intrahepatic and peripheral innate immunity are associated with hepatitis C virus clearance during direct‐acting antiviral therapy

Hepatitis C virus (HCV) infection induces interferon (IFN)‐stimulated genes (ISGs) and downstream innate immune responses. This study investigated whether baseline and on‐treatment differences in these responses predict response versus virological breakthrough during therapy with direct‐acting antivirals (DAAs). Thirteen HCV genotype 1b–infected patients who had previously failed a course of pegylated IFN/ribavirin were retreated with asunaprevir/daclatasvir for 24 weeks. After pretreatment biopsy, patients were randomized to undergo a second biopsy at week 2 or 4 on therapy. Microarray and NanoString analyses were performed on paired liver biopsies and analyzed using linear mixed models. As biomarkers for peripheral IFN responses, peripheral blood natural killer cells were assessed for phosphorylated signal transducer and activator of transcription 1 (pSTAT1) and tumor necrosis factor–related apoptosis‐inducing ligand (TRAIL) expression and degranulation. Nine of 13 (69%) patients achieved sustained virological response at 12 weeks off therapy (SVR12), and 4 experienced virological breakthroughs between weeks 4 and 12. Patients who achieved SVR12 displayed higher ISG expression levels in baseline liver biopsies and a higher frequency of pSTAT1 and TRAIL‐expressing, degranulating natural killer cells in baseline blood samples than those who experienced virological breakthrough. Comparing gene expression levels from baseline and on‐therapy biopsies, 408 genes (±1.2‐fold, P < 0.01) were differentially expressed. Genes down‐regulated on treatment were predominantly ISGs. Down‐regulation of ISGs was rapid and correlated with HCV RNA suppression. Conclusion: An enhanced IFN signature is observed at baseline in liver and blood of patients who achieve SVR12 compared to those who experience a virological breakthrough; the findings suggest that innate immunity may contribute to clearance of HCV during DAA therapy by preventing the emergence of resistance‐associated substitutions that lead to viral breakthrough during DAA therapy.

Markers of Microbial Translocation Are Elevated in Hepatitis B (HBV) and Hepatitis C (HCV) Infection; A Window Into Biology and Surrogate Markers for Detecting Disease Progression

Purpose: In patients with HBeAgpositive chronic hepatitis B (CHB), one of the primary endpoints of therapy is HBeAg seroconversion; however, there is inconsistent data on the durability of HBeAg seroconversion following consolidation therapy. Our goal is to investigate the rate of recurrent HBV viremia in CHB patients after HBeAg seroconversion. Methods: We retrospectively studied 88 consecutive CHB patients who achieved treatment-induced HBeAg seroconversion among the 458 HBeAg-positive patients treated with various antiviral regimens at 3 GI and liver clinics in the U.S. between 3/1998 and 9/2010. HBeAg seroconversion was defined as loss of HBeAg and development of hepatitis B e antibody (anti-HBe). Recurrent HBV viremia was defined as reappearance of detectable HBV DNA (>100 IU/mL) from nadir in two consecutive laboratory tests. Results: Patients were stratified into two groups: Group I 49 patients who remained on therapy, and Group II 39 patients who discontinued therapy following HBeAg seroconversion. In both groups, the majority of patients were Asian (94-95%) and male (62-69%). Antiviral medications in which patients achieved HBeAg seroconversion included: lamivudine (23%), adefovir (34%), entecavir (36%), tenofovir (4%), adefovir+lamivudine (1%), and entecavir+tenofovir (2%). Median treatment duration before HBeAg seroconversion was similar in Group I and Group II (18 [1-86] vs. 21 [5-63] months, p=0.99). At the time of HBeAg seroconversion, compared to Group I, Group II was younger (37±10 vs. 41±12 years), had lower mean HBV DNA levels (0.27±0.78 vs. 0.95±1.69 log10 IU/mL), and median ALT levels (24 [8-60] vs. 30 [593] U/L). In Group II, the median duration of consolidation therapy before treatment discontinuation was 12 months (range, 1-55), in which 10 completed <6 months, 10 completed 6-11 months, and 19 completed ≥12 months. At time of treatment discontinuation, all patients in Group II had undetectable HBV DNA. The rate of recurrent HBV viremia was significantly higher in Group II compared to Group I (90% vs. 0%, p<0.0001). After a median of 3 (1-42) months off therapy, the mean HBV DNA level detected at time of recurrent HBV viremia was 4.11±1.92 log10 IU/mL. Conclusion: The majority of patients (90%) who discontinued therapy after achieving HBeAg seroconversion with undetectable HBV DNA by PCR experienced recurrent HBV viremia. Patients who remained on therapy achieved and maintained undetectable level of HBV DNA. Patients should be monitored closely for recurrent HBVwhen therapy is discontinued, despite achieving HBeAg seroconversion.

Spleen and Liver Volumetrics as Surrogate Markers of Hepatic Venous Pressure Gradient in Patients With Noncirrhotic Portal Hypertension

Noncirrhotic portal hypertension (NCPH) is a rare disease that may lead to serious clinical consequences. Currently, noninvasive tools for the assessment of NCPH are absent. We investigated the utility of spleen and liver volumetrics as a marker of the presence and severity of portal hypertension in this population. A cohort of NCPH patients evaluated between 2003 and 2015 was retrospectively studied. The association of spleen and liver volumes with the hepatic venous pressure gradient (HVPG) level was evaluated using locally weighted scatterplot smoothing curves. A cohort of patients with viral hepatitis‐related liver disease was used as controls. Of the 86 patients with NCPH evaluated during the study period, 75 (mean age, 35 ± 17; 73% males) were included in the final analysis. Patients with portal hypertension had significantly higher spleen and liver to body mass index (BMI) ratios compared to patients with HVPG <5 mm Hg (39.5 ± 27.9 versus 22.8 ± 10.6 cm3/kg/m2, P = 0.003; 91.1 ± 40.1 versus 71.4 ± 16.7 cm3/kg/m2, P = 0.014, for spleen/BMI and liver/BMI, respectively). In contrast to the patients with viral hepatitis, a positive linear correlation was observed in the NCPH cohort between spleen/BMI and liver/BMI (above a cutoff of 25 and 80 cm3/kg/m2, respectively) and HVPG level. Additionally, only in the NCPH cohort was an increase in spleen/BMI range quartile predictive of a higher prevalence of portal hypertension and clinically significant portal hypertension (trend, P = 0.014 and 0.031, respectively). Conclusion: Spleen and liver volumetrics may have utility in the assessment of NCPH as a noninvasive biomarker that can be performed using routine radiologic examinations. Further studies are needed to validate these findings. (Hepatology Communications 2018; 00:000‐000)