Reduction of ACE2 Serum Concentrations by Telbivudine in Chronic Hepatitis B Patients.

BACKGROUND: Coronavirus disease 2019, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has wreaked havoc worldwide since December 2019. Currently, no effective medical treatments have been approved. As the epidemic continues to spread, SARS-CoV-2 mutants emerge, some of which become more infectious with increasing vaccine resistance. The main route for SARS-CoV-2 to enter the host cells is by binding its spike protein to the host receptor, angiotensin-converting enzyme 2 (ACE2). Besides the membrane-bound form of ACE2, the soluble form of ACE2 (sACE2) can also bind SARS-CoV-2 for viral endocytosis. OBJECTIVE: Previously, we found that telbivudine reduced the concentrations of ACE1 in blood. Therefore, we speculated that this drug might also reduce the concentrations of sACE2. METHODS: In this retrospective study, serum samples from 39 hepatitis B patients receiving telbivudine were collected and examined for sACE2 concentrations using an ELISA kit.. RESULTS: It was found that the serum concentrations of sACE2 were significantly declined in chronic hepatitis B patients treated with telbivudine. CONCLUSION: Telbivudine treatment reduced sACE2 concentrations, which could potentially reduce the infection risk of SARS-CoV-2.

Comparison of tenofovir disoproxil fumarate and telbivudine in preventing hepatitis B transmission in mothers with high viral load.

OBJECTIVE: To add to the limited data that exist on the selection of drugs to prevent mother-to-child transmission (MTCT) of hepatitis B virus (HBV). METHODS: This is a prospective cohort study that enrolled mothers with HBV-DNA ≥2 × 105  IU/ml. All enrolled mothers received either tenofovir disoproxil fumarate (TDF) or telbivudine (LdT) to prevent HBV transmission. RESULTS: A total of 270 mothers received TDF treatment and 275 mothers received LdT treatment. The predelivery decline in HBV-DNA in the TDF group was higher than the LdT group (3.92 ± 0.93 log IU/ml vs. 3.76 ± 0.94 log IU/ml, P = 0.043). In the primary analysis, the MTCT rate of the TDF group was comparable to that of the LdT group, both in the intention-to-treat analysis (1.5% [4/275] vs. 1.8% [5/273], P > 0.99) and the per-protocol analysis (0% in both groups, P > 0.99). The alanine aminotransferase elevation rates in the TDF group were lower than in the LdT group (17.3% vs. 27.4%, P = 0.005). Less anorexia and more arthralgia were observed in the LdT group than the TDF group. CONCLUSIONS: TDF and LdT are both effective in preventing MTCT of HBV, but they may cause different adverse events. TDF is more effective in reducing HBV viral load and had fewer alanine aminotransferase abnormalities than LdT.

Quantification and epigenetic evaluation of the residual pool of hepatitis B covalently closed circular DNA in long-term nucleoside analogue-treated patients.

Hepatitis B virus (HBV) covalently closed circular (ccc)DNA is the key genomic form responsible for viral persistence and virological relapse after treatment withdrawal. The assessment of residual intrahepatic cccDNA levels and activity after long-term nucleos(t)ide analogues therapy still represents a technical challenge. Quantitative (q)PCR, rolling circle amplification (RCA) and droplet digital (dd)PCR assays were used to quantify residual intrahepatic cccDNA in liver biopsies from 56 chronically HBV infected patients after 3 to 5 years of telbivudine treatment. Activity of residual cccDNA was evaluated by quantifying 3.5 kB HBV RNA (preC/pgRNA) and by assessing cccDNA-associated histone tails post-transcriptional modifications (PTMs) by micro-chromatin immunoprecipitation. Long-term telbivudine treatment resulted in serum HBV DNA suppression, with most of the patients reaching undetectable levels. Despite 38 out of 56 patients had undetectable cccDNA when assessed by qPCR, RCA and ddPCR assays detected cccDNA in all-but-one negative samples. Low preC/pgRNA level in telbivudine-treated samples was associated with enrichment for cccDNA histone PTMs related to repressed transcription. No difference in cccDNA levels was found according to serum viral markers evolution. This panel of cccDNA evaluation techniques should provide an added value for the new proof-of-concept clinical trials aiming at a functional cure of chronic hepatitis B.

Efficacy of Nucleotide/Nucleoside Analogues and Hepatitis B Immunoglobulin Therapy in Blocking Mother-to-Child Transmission of Hepatitis B in an Eastern Chinese Group.

The objective of this study was to investigate the efficacy and potential side-effects of nucleotide/nucleoside analogues and hepatitis B immunoglobulin injection of newborns in blocking mother-to-child transmission of hepatitis B virus in the middle and late pregnancy period. 238 cases of enrolled pregnant women were divided into the Telbivudine group, the Tenofovir group, the Lamivudine group, and the hepatitis B immunoglobulin (HBIG) group. Enrolled patients received corresponding therapies. Clinical and laboratory data were collected. Results showed that the levels of HBV DNA of the enrolled pregnant women in the Telbivudine, Tenofovir, and Lamivudine groups decreased rapidly after 12 weeks of drug intervention compared with those in the control. HBsAg positive rate in newborns and in children 24 weeks after birth was 0/60, 0/60, 0/60, 3/30, and 11/28 in the Telbivudine, Tenofovir, Lamivudine, HBIG, and control groups, respectively. No significant side-effects were identified after following up to 12 months after birth. Our results show that routine HBV vaccine plus HBIG injections is insufficient in blocking mother-to-child HBV transmission. Administration of nucleotide/nucleoside analogues or HBIG at pregnancy is suggested to maximize the blocking of vertical HBV transmission.

Kinetics of hepatitis B surface antigen and estimated glomerular filtration rate in telbivudine-treated hepatitis B patients with different rescue strategies.

This study investigated the kinetics of estimated glomerular filtration rate (eGFR) and quantitative hepatitis B surface antigen (qHBsAg) in telbivudine (LdT)-treated chronic hepatitis B (CHB) patients whose treatment was subsequently adjusted with the adding on adefovir or by switching to tenofovir disoproxil fumarate (TDF) as rescue. Of 295 CHB patients initially treated with LdT, 102 of them who subsequently receiving either adding-on adefovir (group A, n = 58) or switching to TDF (group B, n = 44) for more than 24 months were enrolled. Serial eGFR and qHBsAg levels (3 to 6 monthly) in both LdT monotherapy and rescue therapy periods were analyzed retrospectively. Subsequent decline of qHBsAg especially in rescue therapy period were noted (p<0.001 and p = 0.068 in group A and B). However, patients in group B achieved a significant increase of eGFR (p = 0.010) in LdT monotherapy period but had a significant decline of eGFR (p<0.001) in rescue therapy period. In contrast, patients in group A maintained eGFR levels in both periods. Meanwhile, switch to TDF (hazard ratio: 3.036; 95% confidence interval: 1.040-8.861; p = 0.042) was the sole factor related to the decrease of eGFR>20% from baseline. Both rescue therapies achieved subsequent declines of qHBsAg over time but caused different changes in eGFR. LdT-based rescue therapy maintained eGFR but TDF switching therapy descended eGFR. Therefore, it is essential to monitor patient's renal function intensively when switching from LdT to TDF as a rescue strategy.

Combination of saikosaponin c and telbivudine synergistically enhances the anti-HBV activity.

OBJECTIVE: The present study was undertaken to obtain data using the combination of SSc and lamivudine (LAM), entecavir (ETV) or telbivudine (LdT) in HepG2.2.15 cells to explore whether SSc acts as a potent adjuvant of nucleoside analogues in anti-HBV treatment. METHODS: HepG2.2.15 cells were incubated with either SSc combined with any one of three nucleoside analogues (NAs) LAM, ETV, LdT or only one of them for 48 h. The expression profiles of HBV DNA, HBsAg, HBeAg, and HBcAg were examined by real-time quantitative PCR, ELISA, and western blot. RESULTS: Compared with mono-drug treatment, the combination of SSc and any of the three nucleoside analogues significantly promoted additional reduction on HBV DNA level. Declined levels of HBsAg, HBeAg, and HBcAg were observed in SSc and LdT combination group. CONCLUSION: These in vitro results indicated that SSc acted as a promising nucleoside analogue adjuvant, especially for telbivudine in the therapeutic strategies against HBV infection.

Telbivudine for renal transplant recipients with chronic hepatitis B infection: a randomized controlled trial with early termination.

BACKGROUND: The aim of this study was to analyze changes in renal function in HBsAg-positive renal transplant recipients receiving lamivudine who did or did not switch to telbivudine. METHODS: In this prospective randomized clinical trial (RCT), HBsAg-positive renal transplant recipients who had received lamivudine prophylaxis for at least 6 months were 1:2 randomized to receive either lamivudine or telbivudine for another 24 months. Renal function was evaluated by creatinine level and estimated glomerular filtration rate (eGFR) at the time of randomization (baseline), 6, 12, 18, and 24 months respectively. RESULTS: This RCT was prematurely terminated after recruiting only 17 patients due to a high incidence (61.5%; 8/13) of clinical myalgia in the telbivudine group. Cox's proportional hazards model revealed that there was no independent predictor of myalgia. Based on intention-to-treat and per protocol analyses using generalized estimating equations, the patients in the randomized telbivudine group had a significantly increased eGFR and the patients in the lamivudine group had a significantly decreased eGFR at the end of follow-up compared to the values at study enrollment. However, there was no significant difference between the lamivudine and telbivudine groups. CONCLUSIONS: The renal protective effect of telbivudine for HBsAg positive renal transplant recipients was uncertain for high incidence of myalgia and only patients who were on telbivudine for 24 months had renal function maintenance.

Telbivudine antagonizes TLR4 to inhibit the epithelial-to-mesenchymal transition in human proximal tubular epithelial cells in vitro.

The antiviral drug Telbivudine (LdT) has an extrahepatic pharmaceutical effect that improves renal inflammation and tubulointerstitial fibrosis. However, the exact mechanism of action requires further investigation. Toll-like receptor 4 (TLR4) is involved in several physiological processes, including inflammation, fibrosis, innate immunity, and hepatitis B virus-associated glomerulonephritis. The epithelial-to-mesenchymal transition (EMT) is the characteristic pathological change in tubulointerstitial fibrosis. In this study, we used transforming growth factor-ß (TGF-ß) to stimulate human proximal tubular epithelial (HK-2) cells to investigate the effects of LdT in EMT. In addition, we treated HK-2 cells with a TLR4 agonist, lipopolysaccharide, to determine the effect of LdT on TLR4. The results indicated that LdT inhibited the expression of TLR4 and its downstream proteins. It also decreased the release of inflammatory factors, downregulated the TGF-ß/Smad signaling pathway, and reversed the EMT changes seen in HK-2 cells. In conclusion, LdT antagonized TLR4 to inhibit EMT in proximal tubular epithelial cells.

Telbivudine Reduces Parvovirus B19-Induced Apoptosis in Circulating Angiogenic Cells.

Aims: Human parvovirus B19 (B19V) infection directly induces apoptosis and modulates CXCR4 expression of infected marrow-derived circulating angiogenic cells (CACs). This leads to dysfunctional endogenous vascular repair. Treatment for B19V-associated disease is restricted to symptomatic treatment. Telbivudine, a thymidine analogue, established in antiviral treatment for chronic hepatitis B, modulates pathways that might influence induction of apoptosis. Therefore, we tested the hypothesis of whether telbivudine influences B19V-induced apoptosis of CAC. Methods and Results: Pretreatment of two CAC-lines, early outgrowth endothelial progenitor cells (eo-EPC) and endothelial colony-forming cells (ECFC) with telbivudine before in vitro infection with B19V significantly reduced active caspase-3 protein expression (-39% and -40%, both p < 0.005). Expression of Baculoviral Inhibitor of apoptosis Repeat-Containing protein 3 (BIRC3) was significantly downregulated by in vitro B19V infection in ECFC measured by qRT-PCR. BIRC3 downregulation was abrogated with telbivudine pretreatment (p < 0.001). This was confirmed by single gene PCR (p = 0.017) and Western blot analysis. In contrast, the missing effect of B19V on angiogenic gene expression postulates a post-transcriptional modulation of CXCR4. Conclusions: We for the first time show a treatment approach to reduce B19V-induced apoptosis. Telbivudine reverses B19V-induced dysregulation of BIRC3, thus, intervening in the apoptosis pathway and protecting susceptible cells from cell death. This approach could lead to an effective B19V treatment to reduce B19V-related disease.

Tryptophan 32 mediates SOD1 toxicity in a in vivo motor neuron model of ALS and is a promising target for small molecule therapeutics.

SOD1 misfolding, toxic gain of function, and spread are proposed as a pathological basis of amyotrophic lateral sclerosis (ALS), but the nature of SOD1 toxicity has been difficult to elucidate. Uniquely in SOD1 proteins from humans and other primates, and rarely in other species, a tryptophan residue at position 32 (W32) is predicted to be solvent exposed and to participate in SOD1 misfolding. We hypothesized that W32 is influential in SOD1 acquiring toxicity, as it is known to be important in template-directed misfolding. We tested if W32 contributes to SOD1 cytotoxicity and if it is an appropriate drug target to ameliorate ALS-like neuromuscular deficits in a zebrafish model of motor neuron axon morphology and function (swimming). Embryos injected with human SOD1 variant with W32 substituted for a serine (SOD1W32S) had reduced motor neuron axonopathy and motor deficits compared to those injected with wildtype or disease-associated SOD1. A library of FDA-approved small molecules was ranked with virtual screening based on predicted binding to W32, and subsequently filtered for analogues using a pharmacophore model based on molecular features of the uracil moiety of a small molecule previously predicted to interact with W32 (5'-fluorouridine or 5'-FUrd). Along with testing 5'-FUrd and uridine, a lead candidate from this list was selected based on its lower toxicity and improved blood brain barrier penetrance; telbivudine significantly rescued SOD1 toxicity in a dose-dependent manner. The mechanisms whereby the small molecules ameliorated motor neuron phenotypes were specifically mediated through human SOD1 and its residue W32, because these therapeutics had no measurable impact on the effects of UBQLN4D90A, EtOH, or tryptophan-deficient human SOD1W32S. By substituting W32 for a more evolutionarily conserved residue (serine), we confirmed the significant influence of W32 on human SOD1 toxicity to motor neuron morphology and function; further, we performed pharmaceutical targeting of the W32 residue for rescuing SOD1 toxicity. This unique residue offers future novel insights into SOD1 stability and toxic gain of function, and therefore poses an potential target for drug therapy.