Metabolomics for identifying pathways involved in vesicating agent lewisite-induced corneal injury.

Lewisite (LEW) is an arsenical vesicant that can be a potentially dangerous chemical warfare agent (CWA). Eyes are particularly susceptible to vesicant induced injuries and ocular LEW exposure can act swiftly, causing burning of eyes, edema, inflammation, cell death and even blindness. In our previous studies, we developed a LEW exposure-induced corneal injury model in rabbit and showed increased inflammation, neovascularization, cell death, and structural damage to rabbit corneas upon LEW exposure. In the present study, we further assessed the metabolomic changes to delineate the possible mechanisms underlying the LEW-induced corneal injuries. This information is vital and could help in the development of effective targeted therapies against ocular LEW injuries. Thus, the metabolomic changes associated with LEW exposures in rabbit corneas were assessed as a function of time, to delineate pathways from molecular perturbations at the genomic and proteomic levels. New Zealand white rabbit corneas (n = 3-6) were exposed to LEW vapor (0.2 mg/L; flow rate: 300 ml/min) for 2.5 min (short exposure; low dose) or 7.5 min (long-exposure; high dose) and then collected at 1, 3, 7, or 14 days post LEW exposure. Samples were prepared using the automated MicroLab STAR® system, and proteins precipitated to recover the chemically diverse metabolites. Metabolomic analysis was carried out by reverse phase UPLC-MS/MS and gas chromatography (GC)-MS. The data obtained were analyzed using Metabolon's software. The results showed that LEW exposures at high doses were more toxic, particularly at the day 7 post exposure time point. LEW exposure was shown to dysregulate metabolites associated with all the integral functions of the cornea and cause increased inflammation and immune response, as well as generate oxidative stress. Additionally, all important metabolic functions of the cells were also affected: lipid and nucleotide metabolism, and energetics. The high dose LEW exposures were more toxic, particularly at day 7 post LEW exposure (>10-fold increased levels of histamine, quinolinate, N-acetyl-ß-alanine, GMP, and UPM). LEW exposure dysregulated integral functions of the cornea, caused inflammation and heightened immune response, and generated oxidative stress. Lipid and nucleotide metabolism, and energetics were also affected. The novel information about altered metabolic profile of rabbit cornea following LEW exposure could assist in delineating complex molecular events; thus, aid in identifying therapeutic targets to effectively ameliorate ocular trauma.

Genomic landscape of chemical-induced lung tumors under Nrf2 different expression levels.

The transcription factor Nrf2 plays a crucial role in the anti-oxidative stress response, protection of DNA from injury and DNA repair mechanisms. Nrf2 activity reduces cancer initiation, but how Nrf2 affects whole-genome alterations upon carcinogenic stimulus remains unexplored. Although recent genome-wide analysis using next-generation sequencing revealed landscapes of nucleotide mutations and copy number alterations in various human cancers, genomic changes in murine cancer models have not been thoroughly examined. We elucidated the relationship between Nrf2 expression levels and whole exon mutation patterns using an ethyl-carbamate (urethane)-induced lung carcinogenesis model employing Nrf2-deficient and Keap1-kd mice, the latter of which express high levels of Nrf2. Exome analysis demonstrated that single nucleotide and trinucleotide mutation patterns and the Kras mutational signature differed significantly and were dependent on the expression level of Nrf2. The Nrf2-deficient tumors exhibited fewer copy number alterations relative to the Nrf2-wt and Keap1-kd tumors. The observed trend in genomic alterations likely prevented the Nrf2-deficient tumors from progressing into malignancy. For the first time, we present whole-exome sequencing results for chemically-induced lung tumors in the Nrf2 gain or loss of function mouse models. Our results demonstrate that different Nrf2 expression levels lead to distinct gene mutation patterns that underly different oncogenic mechanisms in each tumor genotype.

Histological response to combination therapy with nucleos(t)ide analogs and peginterferon alpha in treatment-naïve chronic hepatitis B patients.

Although nucleos(t)ide analog (NA) monotherapy is effective in hepatitis B virus suppression and fibrosis regression, serological response rates are not satisfactory. Studies assessing the benefits of combination therapy with NAs and peginterferon alpha (PegIFNα) in patients with chronic hepatitis B (CHB) have produced conflicting results and mainly focused on serological outcomes. Histological changes in response to combination therapy have not been evaluated in real-world practice. This study aimed to evaluate the histological changes in response to NA-PegIFNα combination therapy in CHB patients and to comprehensively compare the efficacy of NA-PegIFNα combination therapy and NA monotherapy. We conducted a retrospective analysis of data from 40 CHB patients who underwent either NA-PegIFNα combination therapy or NA monotherapy. Changes in histology at 48 weeks after treatment initiation were evaluated. Serological characteristics were also analysed and compared between the NA-PegIFNα combination therapy and NA monotherapy groups and between histological responders and nonresponders. Compared to baseline biopsies, both fibrosis staging and necroinflammatory grading scores were significantly lower in the second biopsies examined post-treatment in both groups. Nearly all patients experienced a reduction in inflammation (87.5% in both groups), but there was a subgroup of patients who exhibited either no significant improvement or fibrosis progression (33.3% and 31.2% in the NA monotherapy and NA-PegIFNα combination therapy groups, respectively). Nearly, all patients achieved ALT normalization and sustained virological response (SVR) after 48 weeks of antiviral treatment. Approximately one-third of individuals (36.8% and 30% in the two groups, respectively) achieved HBeAg loss at 48 weeks after treatment initiation. Although there were no significant differences in overall rates of histological, biochemical, virological and serological responses between the two groups, an earlier virological response and a higher cumulative SVR rate over time were observed during long-term follow-up in patients treated with NA-PegIFNα combination therapy (P = 0.0129). Trends of more rapid HBeAg loss and a higher cumulative HBeAg loss rate throughout long-term follow-up were also observed but were not statistically significant. The ALT normalization rates at 24 and 48 weeks after treatment initiation were associated with the histological response. Significant regression of fibrosis and resolution of necroinflammation were induced with either NA-PegIFNα combination therapy or NA monotherapy. Significant biochemical, virological and serological responses were observed in both groups, and the response rates at 48 weeks were similar in the two groups. Over time during long-term follow-up, the virological and serological responses were faster and superior following the combination regimen.

Effect of Nucleos(t)ide Analogue Therapy on Risk of Intrahepatic Cholangiocarcinoma in Patients With Chronic Hepatitis B.

BACKGROUND & AIMS: Chronic infection with hepatitis B virus (HBV) increases risk of intrahepatic cholangiocarcinoma (ICC), but it is not clear whether antiviral therapy reduces risk. We investigated the association between nucleos(t)ide analogue therapy and ICC risk. METHODS: We performed a nationwide long-term cohort study using Taiwan's National Health Insurance Research Database to obtain data on 185,843 patients with chronic HBV infection from October 1, 2003 through December 31, 2012. We excluded patients with confounding disorders such as infection with hepatitis C virus, HIV, or other hepatitis-associated viruses; liver flukes; biliary stone diseases; cholangitis; congenital biliary anomalies; biliary tract surgeries; or cancer. We identified 10,062 patients who received nucleos(t)ide analogue therapy (the treated group), and used propensity scores to match them (1:1) with patients who received hepatoprotectants (the untreated group). Cumulative incidences of and hazard ratios (HRs) for ICC development were analyzed. RESULTS: The cumulative incidence of ICC was significantly lower in the treated group after 3 years of therapy (1.28%; 95% CI, 0.56-2.01) than in the untreated group (3.14%; 95% CI, 2.02-4.27) and after 5 years of therapy (1.53%; 95% CI, 0.73-2.33 vs 4.32% in untreated group; 95% CI, 2.96-5.6869). In multivariable regression analysis, nucleos(t)ide analogue therapy was independently associated with a reduced risk of ICC (HR, 0.44; 95% CI, 0.25-0.78; P = .005). Older age (HR 1.05 per year; 95% CI, 1.03-1.07) and cirrhosis (HR, 2.80; 95% CI, 1.52-5.1415) were independently associated with an increased risk of ICC. Sensitivity analyses verified the association between nucleos(t)ide analogue therapy and a reduced ICC risk. CONCLUSION: A nationwide long-term cohort study in Taiwan showed that nucleos(t)ide analogue therapy for chronic HBV infection is significantly associated with a reduced ICC risk.

Serum NGAL can act as an early renal safety biomarker during long-term nucleos(t)ide analogue antiviral therapy in chronic hepatitis B.

Tubular renal toxicity is a side-effect of long-term therapy with nucleos(t)ide analogue(s) (NA) in chronic hepatitis B (CHB). There are no established surrogate markers in plasma of early NA-related toxicity. Neutrophil gelatinase-associated lipocalin (NGAL) is a protein produced by tubular cells following renal damage. We aimed therefore to retrospectively compare conventional renal markers (estimated glomerular filtration rates (eGFR) and urinary protein/creatinine ratio uPCR) with a sensitive biomarker (NGAL) in CHB patients on long-term NA therapy and assess the ability of new markers to predict NA-related renal toxicity (new onset of nonalbumin proteinuria). A total of 192 naïve CHB patients (median age 41 years, 78% males, 25% HBeAg+, 35% cirrhosis) were NA treated for at least 5 years (median 8.34 years, range 5.54-11.1 years). The eGFR and uPCR were compared at baseline and last clinical visit with serum NGAL concentrations measured by ELISA at same time-points and assessed according to the presence/absence of nonalbumin proteinuria at last visit. While baseline and last visit eGFR were similar (median:78 vs 84 mL/min), serum NGAL concentrations increased during therapy (median:9.4 vs 16.4 ng/mL, P < .05). The proportion of patients with proteinuria (uPCR > 15) increased between baseline and last visit (4.6% vs 21.4%, P < .05), with 30 (16%) patients having de novo nonalbumin proteinuria at last visit. High baseline NGAL concentrations were exclusive to patients with de novo nonalbumin proteinuria (median:31.7 vs 7.8 ng/mL, P < .01) and baseline NGAL levels >25 mg/mL were predictive of nonalbumin proteinuria at last visit (AUROC = 0.813). In conclusion, serum NGAL can act as a surrogate marker of early renal injury (de novo nonalbumin proteinuria) in CHB on long-term NA therapy.

[Chronic hepatitis B and D (delta) : Current and future treatments]. / Chronische Hepatitis B und D (delta) : Gegenwärtige und zukünftige Therapien.

BACKGROUND: Worldwide, hepatitis B virus (HBV) infection is among the 30 leading causes of death, despite effective vaccination and therapeutic options. Chronic hepatitis delta (coinfection with hepatitis D virus) leads to a rapid disease progression. AIMS: Based on current international guidelines and studies, an overview about present and future therapeutic options for chronic hepatitis B and delta is provided. RESULTS: Therapy with nucleoside or nucleotide analogues leads to nearly complete HBV DNA suppression, which is associated with regression of liver fibrosis and a lower risk for the development of hepatocellular carcinoma. Therapy of chronic hepatitis delta with pegylated interferon alfa achieves only low response rates with high risk for virological relapse. Various therapeutic approaches are currently being investigated in preclinical and clinical studies and have led to a significant reduction of hepatitis B surface antigen (HBsAg) and HDV RNA. CONCLUSION: Current therapies of chronic HBV infection can effectively reduce subsequent complications. New therapeutic approaches promise functional cure (HBsAg loss) of HBV infection and effective treatment options for patients with chronic hepatitis delta.

Long-term safety of oral nucleos(t)ide analogs for patients with chronic hepatitis B: A cohort study of 53,500 subjects.

UNLABELLED: Widespread and long-term use of oral nucleos(t)ide analogs (NAs) to treat chronic hepatitis B (CHB) brings about safety data in a real-life setting. We aimed to determine the risks of renal and bone side effects in patients receiving or who have received NAs as CHB treatment. A territory-wide cohort study using the database from Hospital Authority, the major provider of medical services in Hong Kong, was conducted. We identified CHB patients by International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis codes, diagnosed between 2000 and 2012. The primary events were renal (incident renal failure and renal replacement therapy [RRT]) and bone events (incident hip, vertebral, and all fractures). A 3-year landmark analysis was used to evaluate the relative risk of primary outcome in patients with or without NA treatment. A total of 53,500 CHB patients (46,454 untreated and 7,046 treated), who were event free for 3 years, were included in the analysis. At a median follow-up of 4.9 years, chronic renal failure, RRT, all fractures, hip fractures, and vertebral fractures occurred in 0.6%, 0.2%, 0.7%, 0.1%, and 0.1% of untreated subjects and 1.4%, 0.7%, 1.3%, 0.2%, and 0.2% of treated subjects. After propensity score weighting, NA therapy did not increase the risk of any of the events (hazard ratios [HRs] ranged from 0.79 to 1.31; P = 0.225-0.887). Exposure to nucleotide analogues, compared with nucleoside analogs, increased the risk of hip fracture (HR = 5.69; 95% confidence interval: 1.98-16.39; P = 0.001), but not other events (HR = 0.58-1.44; P = 0.202-0.823). CONCLUSIONS: NA treatment does not increase the risk of renal and bone events in general. Nucleotide analogs may increase the risk of hip fracture, but the overall event rate is low.

Altered Underlying Renal Tubular Function in Patients With Chronic Hepatitis B Receiving Nucleos(t)ide Analogs in a Real-World Setting: The MENTE Study.

BACKGROUND: Cases of renal tubular dysfunction have been reported in patients with hepatitis B and in patients with human immunodeficiency virus who are undergoing tenofovir treatment. However, little is known about the impact on tubular function in patients with chronic hepatitis B (CHB) under long-term use of entecavir (ETV) and tenofovir disoproxil fumarate (TDF). We evaluated markers of renal tubular function and bone turnover in patients with CHB treated with ETV or TDF. PATIENTS AND METHODS: A multicenter, cross-sectional study was performed on markers of renal tubular function and bone turnover in hepatitis B virus-monoinfected patients on long-term treatment with Entecavir or Tenofovir (the MENTE study). The analyzed parameters were: retinol-binding protein/creatinine, neutrophil gelatinase-associated lipocalin/creatinine, excretion of phosphates, uric acid excretion, glomerular filtrate, protein/creatinine, albumin/creatinine, serum creatinine, phosphate, CTX, P1NP, vitamin D, and parathormone. RESULTS: A total of 280 patients (ETV: 89, TDF: 69, control: 122) were included in this study. The TDF group was associated with altered levels of retinol-binding protein (RBP)/creatinine (TDF 25% vs. 7% ETV and control; P<0.001). Protein/creatinine, uric acid excretion, P1NP1, and parathormone were higher in the TDF group. The proportion of patients with serum phosphate <2.5 mg/dL was higher in both the ETV and the TDF groups compared with the control. The multivariate analysis showed that the use of TDF was independently associated with a higher risk of altered excretion of RBP/creatinine (4.4; interquartile range: 1.4 to 14; P=0.013). CONCLUSIONS: We found an independent association between TDF use and altered RBP excretion. This finding indicates subclinical tubular damage. Because tubular dysfunction can precede the decline of renal function, close monitoring of RBP levels in patients with CHB on nucleos(t)ide analog treatment must be performed for early detection of TDF-related renal toxicity. In this study, these differences in tubular function were not associated with concomitant changes in markers of bone turnover.

Nucleos(t)ide analogues causes HBV S gene mutations and carcinogenesis.

BACKGROUND: The long-term use of nucleos(t)ide analogues causes drug resistance and mutations in the HBV reverse transcriptase (RT) region of the polymerase gene. The RT region overlaps the HBV surface gene (S gene) and therefore, the mutations in the RT region simultaneously modify S gene sequence. Certain mutations in the RT region bring about truncated S proteins because the corresponding changed S gene encodes a stop codon which results in the loss of a large portion of the C-terminal hydrophobic region of HBV surface protein. The rtA181T/sW172*, rtM204I/sW196* and rtV191I/sW182* are the most frequently reported drug-resistant mutations with C-terminal truncation, these mutations have oncogenic potential. DATA SOURCES: PubMed and Web of Science were searched using terms: "hepatitis B virus", "HBV drug resistance mutation", "HBV surface protein", "HBV truncation", "hepatocellular carcinoma", "rtA181T/sW172*", "rtM204I/sW196*", "rtV191I/sW182*", and relevant articles published in English in the past decades were reviewed. RESULTS: The rtA181T/sW172* and rtV191I/sW182* mutants occurred more frequently than the rtM204I/sW196* mutant both in chronic hepatitis B patients and the HBV-related hepatocellular carcinoma tissues. Although these mutations occur naturally, nucleos(t)ide analogues therapy is the main driving force. These mutations may exist alone or coexist with other HBV mutations. All these three mutants impair the virion secretion and result in HBV surface protein retention and serum HBV DNA level reduction. These mutations possess potential carcinogenic properties. The three mutations are resistant to more than one nucleos(t)ide analogue and therefore, it is difficult to treat the patients with the truncated mutations. CONCLUSIONS: Nucleos(t)ide analogues induce drug resistance and HBV S gene truncated mutations. These mutations have potential carcinogenesis.

Bone Mineral Density and Renal Function in Chronic Hepatitis B Patients Receiving Nucleotide versus Nucleoside Analogs: A Pilot Prospective Study.

BACKGROUND: The use of nucleotide analogs (NTAs) can be associated with negative effects on renal function and bone mineral density (BMD) due to proximal tubular dysfunction and hypophosphatemia; however, prospective data assessing the bone and renal safety of these agents are limited. OBJECTIVE: This study aimed to evaluate the prevalence of bone diseases among chronic hepatitis B (CHB) patients without cirrhosis and the changes in BMD and glomerular filtration rate (GFR) between patients receiving NTAs versus nucleoside analogs (NSAs). MATERIAL AND METHOD: We prospectively collected data from non-cirrhotic CHB patients who had been treated for < 1 year in Rajavithi Hospital (Bangkok, Thailand) between 2012 and 2014. Patients with significant comorbidities or those being treated for bone diseases were excluded. BMD assessment was performed at the lumbar spine (LS) and femoral neck (FN). BMD T-scores were used to define osteopenia (-2.5 to -1) and osteoporosis (< -2.5), and the GFR was estimated using the Cockcroft-Gault method. RESULTS: Twenty patients were included: 65% were men; 40% were HBeAg positive; and the median age was 42.7 (25.6-64.2) years. Ten patients had been treated with NTAs (7 with tenofovir 3 with adefovir) and 10 patients had been treated with NSAs (8 with lamivudine, 2 with entecavir), with a median follow-up period of 1.5 years (1.2-1.6). At baseline, the overall prevalence of osteopenia was 45% and the median GFR was 94 (51-144) mL/min. BMD in CHB patients was slightly lower than in an age-matched population based on Z-scores. Changes in LS-BMD and FN-BMD were not significantly different between groups. The annual reduction in GFR was more pronounced in the NTA group (-7.4% vs. -1.39%, p = 0.018). CONCLUSION: Osteopenia is common in CHB patients without cirrhosis. Changes in BMD were not significantly different between groups. The annual reduction in GFR was more pronounced in the NTA group.

[Biomarkers of renal impairment and their application in renal function monitoring during treatment with nucleos(t)ide analogues].

Currently, nucleos(t)ide analogues (NAs) are the major drugs for the antiviral treatment of chronic hepatitis B (CHB), including lamivudine, adefovir dipivoxil, telbivudine, entecavir, and tenofovir disoproxil. Since many patients need to take NAs orally for a long time to inhibit viral replication, the safety of long-term administration is an important factor for selecting drugs in clinical practice. In recent years, some studies have been focusing on the impact of long-term administration of NAs on glomerular filtration function and renal tubular function in such patients. At the same time, more and more biomarkers for evaluating renal impairment have been used in clinical practice, but the applicability of most biomarkers in CHB patients remains uncertain. This review describes the biomarkers that are currently used or have a potential clinical value and investigates the application of such biomarkers in CHB patients in future.

Impact of nucleos(t)ide analogues on the estimated glomerular filtration rate in patients with chronic hepatitis B: a prospective cohort study in China.

Chronic hepatitis B therapy with nucleos(t)ide analogues, particularly tenofovir or adefovir, may affect renal function. To date, there has not been a head-to-head controlled study to assess estimated glomerular filtration rate (eGFR) fluctuations in nucleos(t)ide-treated CHB patients. We aimed to evaluate the long-term effects of nucleos(t)ide on eGFR in Chinese patients with chronic hepatitis B. This prospective cohort study included 275 patients. Patient subgroups included those treated with lamivudine (n = 50), adefovir (n = 60), telbivudine (n = 68) and entecavir (n = 61); untreated patients (n = 36) served as control. After an average follow-up duration of 23 months, eGFR calculated by Cockcroft-Gault and Modification of Diet in Renal Disease formulas increased by 18.35 mL/min and 19.34 mL/min (P < 0.0001) in the telbivudine group, respectively, and decreased by 10.95 mL/min and 12.17 mL/min (P = 0.0001) in the adefovir group, respectively. Even if renal function was normal or mildly impaired at baseline, eGFR increased significantly more in the telbivudine group than in the other groups (P < 0.001). More patients in the adefovir group (23%) had a ≥20% decrease in eGFR than the other groups (P < 0.0001). More patients in the telbivudine group (31%) had a ≥20% increase in eGFR than the other groups (P < 0.0001). In conclusion, prolonged telbivudine therapy resulted in improved eGFR, while adefovir therapy was associated with decreased eGFR. Lamivudine and entecavir therapy did not significantly influence eGFR.

Interferon-free strategies with a nucleoside/nucleotide analogue.

A key to effective interferon- (IFN-) free therapy for hepatitis C virus (HCV) infection is a direct-acting antiviral (DAA) with a high barrier to resistance that can act as the backbone to any regimen. Ideally, this agent should also be active against all HCV genotypes, be well tolerated and have few drug interactions. Nucleoside/nucleotide analogues (NAs) that inhibit the function of the HCV RNA-dependent-RNA polymerase fit these requirements and thus hold promise as a cornerstone for new IFN-free regimens. To date, the issue with this class of agents has been toxicity. Numerous NAs in early clinical development have led to significant toxicity leading to their abandonment. However, sofosbuvir, a prodrug of a uridine NA, has moved through development with a clean-safety profile leading to its recent approval. When combined with ribavirin (RBV) alone, sofosbuvir is effective against genotype 2 and even genotype 3 if duration is extended. There are currently limited data with this combination in genotype 1; however, when sofosbuvir is combined with other DAAs of different classes, it is highly effective in almost all patients. To date, sofosbuvir has been studied with protease, NS5A, and nonnucleoside HCV polymerase inhibitors, including as part of a fixed-dose combination single tablet with the NS5A inhibitor ledipasvir, with very high rates of SVR with as little as 8 weeks of therapy. Combining two DAAs to sofosbuvir may shorten therapy even further. Because of the poor replicative fitness of the S282T sofosbuvir-resistant variant, resistance to sofosbuvir has not been a significant clinical issue in trials thus far. In addition to sofosbuvir, other NAs are in early-stage development. Provided unanticipated toxicity does not emerge, NAs are likely to play a major role as a backbone for future HCV therapy. The rationale for using this class of agents and the clinical data available to date are reviewed.

Extrahepatic effects of nucleoside and nucleotide analogues in chronic hepatitis B treatment.

Oral nucleoside/nucleotide analogues (NAs) are the mainstay of therapy for patients with chronic hepatitis B and are generally well tolerated. Despite this, the safety profile of NAs is of paramount importance since the majority of patients will require long-term treatment. All NAs can potentially affect human DNA polymerase with decrease in mitochondrial DNA, leading to manifestations of mitochondrial toxicity. As a class effect, therefore, NAs can potentially cause extrahepatic conditions, such as myopathy, nephropathy, neuropathy, and lactic acidosis. Indeed, effects on muscles, including myopathy and creatine kinase elevations, have been described with clevudine and telbivudine use. Both adefovir and tenofovir are associated with dose-dependent nephropathy, predominantly affecting the proximal renal tubules. Neuropathy appears to be rare, and most commonly reported in patients receiving combination therapy with telbivudine and interferon. Increased risk of lactic acidosis has also been described for those with impaired liver and renal function taking entecavir. Loss of bone mineral density and hypophosphatemia have been described with the use of NAs, although the overwhelming studies have been with human immunodeficiency virus-infected patients. However, not all extrahepatic effects are detrimental. Recent evidence has suggested a potential renal beneficial effect with the use of telbivudine. The effect of NAs on pregnancy appears to be minimal for all NAs, with telbivudine and tenofovir having a more favorable category B rating. Ongoing pharmacovigilance is essential to identify new and monitor existing extrahepatic effects associated with NA use.

Why do I treat HBeAg-negative chronic hepatitis B patients with nucleos(t)ide analogues?

Products that are currently used in the treatment of chronic hepatitis B include interferon-alpha (IFNa: standard or pegylated) (PEG-IFNa) and nucleos(t)ide analogues (NAs). NAs are used in most HBeAg-negative chronic hepatitis B patients for several reasons. They can be prescribed to all chronic HBV patients, even those with contraindications to IFNa; and even IFNa candidates are usually treated with NAs because of their advantages. Administration of NAs is easier (one oral tablet per day compared with subcutaneous IFNa injections), tolerance is excellent and the safety profile is good, whereas IFNa may have adverse events and often worsens the patients' quality of life. The current first-line NA options, entecavir (ETV) and tenofovir (TDV), have minimal or no risk of long-term resistance and a virological response is achieved in almost 100% of adherent HBeAg-negative patients, thus modifying the long-term outcome. The need for long-term, perhaps indefinite, treatment is the main limitation of NAs and the finite duration (48 weeks), the main advantage of IFNa, especially in young patients of reproductive age. However, at most 25% of IFNa-treated HBeAg-negative patients achieve a sustained off-treatment response and therefore >75% of them will eventually receive NAs, even if they start with IFNa. As there will always be concerns about safety and family planning issues with long-term NA therapy, NAs should be used carefully, particularly in young chronic hepatitis B patients with mild liver disease. Novel therapeutic options are needed to increase the rates of HBsAg loss and sustained off-treatment responses.

The efficacy and safety of nucleos(t)ide analogues in the treatment of HBV-related acute-on-chronic liver failure: a meta-analysis.

BACKGROUND AND PURPOSE: The application of nucleos(t)ide analogues in hepatitis B virus (HBV)-related acute-on-chronic liver failure (ACLF) has not yet been widely accepted. Therefore, we conducted a metaanalysis of prospective and retrospective studies to examine the efficacy and safety of nucleos(t)ide analogues in treating HBV-related ACLF. MATERIAL AND METHODS: Two independent reviewers identified eligible studies through electronic, and manual searches, and contact with experts. Three-month mortality was defined as the primary efficacy measure. ACLF reactivation and HBV DNA inhibition were secondary efficacy measures. Quantitative meta-analyses were performed to compare differences between nucleos(t)ide analogue and control groups. RESULTS: Five eligible studies were identified. Antiviral treatment with nucleos(t)ide analogues led to significant reduction of HBV DNA [HBV DNA reduction > 2 log: 70.4 vs. 29%, RR = 2.29, 95%CI (1.49, 3.53), P < 0.01]. ACLF patients receiving nucleos(t)ide analogue had significantly lower 3-month mortality [44.8 vs. 73.3%, RR = 0.68, 95%CI (0.54, 0.84), P < 0.01] as well as incidence of reactivation [1.80 vs. 18.4%, RR = 0.11, 95%CI (0.03, 0.43), P < 0.01] compared to those who did not. There was no significant difference in the prognosis of patients treated with entecavir or lamivudine [36.4 vs. 40.5%, RR = 0.77, 95%CI (0.45, 1.32), P = 0.35]. No drug-related adverse events were reported during follow-up. CONCLUSION: Our findings suggest that nucleos(t)ide analogue treatment reduces short-term mortality as well as reactivation of HBV-related ACLF patients. Nucleos(t)ide analogues are well-tolerated during therapy, and suggestive evidence indicates that entecavir and lamivudine confer comparable.

[HBV vaccine escape mutations in a chronic hepatitis B patient treated with nucleos(t)ide analogues]. / Nükleoz(t)id analoglari tedavisi altinda HBV asi kaçagi mutasyonlari gelisen bir kronik hepatit B olgusu.

The hepatitis B virus (HBV) polymerase (pol) gene completely overlaps with the envelope (S) gene. Nucleos(t)ide analogue (NA) resistance mutations in the pol gene of HBV, either from selection of primary or secondary resistance mutations, typically result in changes in the overlapping hepatitis B surface antigen (HBsAg). Recent studies have conferred a new acronym to these HBV pol/S gene overlap mutants; ADAPVEMs, for antiviral drug-associated potential vaccine-escape mutants. The present report aimed to assess the determined multiple HBV vaccine-escape mutants in a Turkish patient with chronic hepatitis B (CHB), undergoing NAs treatment. The liver biopsy of HBsAg positive, HBeAg negative 53-year old female patient with CHB, revealed a score as histological activity index; 9 and fibrosis; 2 according to Ishak classification. NA treatment backgrounds consisted of 24 months lamivudine, followed by 18 months entacavir and lastly 3 months tenofovir monotherapies. Since HBV DNA load was determined as 7.030.000 IU/ml at the 4th month of tenofovir therapy, entecavir was added as current treatment regimen, and tenofovir + entecavir therapy decreased the HBV DNA load (400 IU/ml). Sequence analysis was performed for HBV pol/S gene and overlapping pol/S gene amino acid substitutions, primary/compensatory NA resistance mutations and antiviral drug-associated potential vaccine-escape mutations (ADAPVEM) were analysed. The patient isolate was identified as genotype D/subgenotype D1 of HBV. Primary drug resistance mutations (rtV173L + rtL180M + rtM204V) to lamivudine and telbivudine and a compensatory mutation (rtQ215H) to lamivudine and adefovir were described in the HBV pol gene sequence. However, multiple HBV vaccine-escape mutations (sS143T + sD144E + sG145R + sE164D + sI195M) have been determined on the HBV overlapping pol/S gene region. Lamivudine and telbivudine which are the frequently preferred drugs for the treatment of CHB in Turkey, have the potential to lead to ADAPVEMs. Thus ADAPVEMs should be monitored in infected and NA treated CHB patients and their public health risks should be assessed.

First-line treatment of chronic hepatitis B with entecavir or tenofovir in 'real-life' settings: from clinical trials to clinical practice.

Entecavir (ETV) and tenofovir disoproxil fumarate (TDF) are potent nucleos(t)ide analogues (NUCs) recommended as first-line monotherapies for chronic hepatitis B. In Phase III trials, ETV and TDF demonstrated superior efficacy, and comparable safety compared with other NUCs. In long-term clinical studies, both drugs achieved virologic response rates of around 95%, with very low rates of resistance development and good safety profiles. Clinical trials are conducted under standardized conditions with strict enrolment criteria that limit the heterogeneity of study populations. 'Real-life' populations tend to be composed of a wider range of patients, often older and with different morbidities, comorbidities that may impact treatment efficacy and co-factors, such as smoking and alcohol intake, which can have a direct impact on disease progression. Real-life studies provide better representations of everyday clinical practice and are important to confirm the results reported in clinical studies and to identify rare or late-emerging adverse events. In five 'real-life' studies of ETV in more than 1000 patients, up to 4 years of treatment resulted in virologic responses in 76-96% of patients. Two real-life studies of TDF reported response rates of 71-92% after up to 21 months of treatment. Low incidences of drug resistance and favourable tolerabilities were reported for both drugs, thus confirming the results from registration trials.

Tolerability and efficacy of anti-HBV nucleos(t)ide analogues in HBV-DNA-positive cirrhotic patients with HBV/HCV dual infection.

We evaluated tolerability and virological and clinical impact of anti-Hepatitis B Virus (HBV) nucleos(t)ide analogues in cirrhotic patients with HBV/Hepatitis C Virus (HCV) coinfection. The virological and clinical course of 24 consecutive HBsAg/HBV-DNA/anti-HCV-positive patients with cirrhosis was compared with that of 24 HBsAg/HBV-DNA-positive, anti-HCV-negative cirrhotic patients, pair-matched for age (±5 years), sex, HBeAg/anti-HBe status and Child-Pugh class. Patients in both groups were previously untreated with oral antiviral agents at enrollment and were treated for at least 24 months (range 24-54). At the 12th and 18th month of treatment, HBV-DNA was negative in 21 (87.5%) and 23 (95.8%) patients with hepatitis B and C and in 20 (83.3%) and 22 (91.6%) in patients with isolated HBV; all patients in both groups were HBV-DNA-negative at month 24 and at subsequent observations. Treatment was well tolerated by all patients in both groups. At the last observation (for co-infected patients, median 44 months and range 24-54; for mono-infected patients, median 40 months and range 24-54), a deterioration in Child class was observed in eight (47%) of 17 patients in patients with both HBV and HCV who were HCV-RNA-positive at baseline, but in none of seven HCV-RNA-negative patients in the same group, and in one patient (4.2%) in the mono-infected patients. Reactivation of HCV infection was relatively infrequent (12.5% of cases) and never associated with a clinical deterioration. Treatment with nucleotides in HBsAg/HBV-DNA/anti-HCV-positive patients with cirrhosis showed a favourable virological effect in all cases, but a favourable clinical result only in the HCV-RNA-negative at baseline.

Mitochondrial tRNAGln 4394C>T Mutation May Contribute to the Clinical Expression of 1555A>G-Induced Deafness

The mitochondrial 1555A>G mutation plays a critical role in aminoglycoside-induced and non-syndromic hearing loss (AINSHL). Previous studies have suggested that mitochondrial secondary variants may modulate the clinical expression of m.1555A>G-induced deafness, but the molecular mechanism has remained largely undetermined. In this study, we investigated the contribution of a deafness-associated tRNAGln 4394C>T mutation to the clinical expression of the m.1555A>G mutation. Interestingly, a three-generation family with both the m.1555A>G and m.4394C>T mutations exhibited a higher penetrance of hearing loss than another family harboring only the m.1555A>G mutation. At the molecular level, the m.4394C>T mutation resides within a very conserved nucleotide of tRNAGln, which forms a new base-pairing (7T-66A) and may affect tRNA structure and function. Using trans-mitochondrial cybrid cells derived from three subjects with both the m.1555A>G and m.4394C>T mutations, three patients with only the m.1555A>G mutation and three control subjects without these primary mutations, we observed that cells with both the m.1555A>G and m.4394C>T mutations exhibited more severely impaired mitochondrial functions than those with only the m.1555A>G mutation. Furthermore, a marked decrease in mitochondrial RNA transcripts and respiratory chain enzymes was observed in cells harboring both the m.1555A>G and m.4394C>T mutations. Thus, our data suggest that the m.4394C>T mutation may play a synergistic role in the m.1555A>G mutation, enhancing mitochondrial dysfunctions and contributing to a high penetrance of hearing loss in families with both mtDNA pathogenic mutations.