Protocol for detection of pathogenic enteric RNA viruses by regular monitoring of environmental samples from wastewater treatment plants using droplet digital PCR

Background:The present comprehensive protocol is focused on the detection of pathogenic enteric RNA viruses,explicitly focusing on norovirus genogroup II(GII),astrovirus,rotavirus,Aichi virus,sapovirus,hepatitis A and E viruses in wastewater treatment plants through droplet digital PCR(ddPCR).Enteric viruses are of significant public health concern,as they are the leading cause of diseases like gastroenteritis.Regular monitoring of environmental samples,particularly from wastewater treatment plants,is crucial for early detection and control of these viruses.This research aims to improve the understanding of the prevalence and dynamics of enteric viruses in urban India and will serve as a model for similar studies in other regions.Our protocol's objective is to establish a novel ddPCRbased methodology for the detection and molecular characterization of enteric viruses present in wastewater samples sourced from Bhopal,India.Our assay is capable of accurately quantifying virus concentrations without standard curves,minimizing extensive optimization,and enhancing sensitivity and precision,especially for low-abundance targets.Methods:The study involves fortnightly collecting and analyzing samples from nine wastewater treatment plants over two years,ensuring comprehensive coverage and consistent data.Our study innovatively applies ddPCR to simultaneously detect and quantify enteric viruses in wastewater,a more advanced technique.Additionally,we will employ next-generation sequencing for detailed viral genome identification in samples tested positive for pathogenic viruses.Conclusion:This study will aid in understanding these viruses’genetic diversity and mutation rates,which is crucial for developing tailored intervention strategies.The findings will be instrumental in shaping public health responses and improving epidemiological surveillance,especially in localities heaving sewage networks.

Activation of MAPK-mediated immunity by phosphatidic acid in response to positive-strand RNA viruses

Increasing evidence suggests that mitogen-activated protein kinase(MAPK)cascades play a crucial role in plant defense against viruses.However,the mechanisms that underlie the activation of MAPK cascades in response to viral infection remain unclear.In this study,we discovered that phosphatidic acid(PA)repre-sents a major class of lipids that respond to Potato virus Y(PVY)at an early stage of infection.We identified NbPLDa1(Nicotiana benthamiana phospholipase Da1)as the key enzyme responsible for increased PA levels during PVY infection and found that it plays an antiviral role.6K2 of PVY interacts with NbPLDa1,lead-ing to elevated PA levels.In addition,NbPLDa1 and PA are recruited by 6K2 to membrane-bound viral repli-cation complexes.On the other hand,6K2 also induces activation of the MAPK pathway,dependent on its interaction with NbPLDa1 and the derived PA.PA binds to WIPK/SIPK/NTF4,prompting their phosphoryla-tion of WRKY8.Notably,spraying with exogenous PA is sufficient to activate the MAPK pathway.Knock-down of the MEK2-WIPK/SIPK-WRKY8 cascade resulted in enhanced accumulation of PVY genomic RNA.6K2 of Turnip mosaic virus and p33 of Tomato bushy stunt virus also interacted with NbPLDa1 and induced the activation of MAPK-mediated immunity.Loss of function of NbPLDa1 inhibited virus-induced activation of MAPK cascades and promoted viral RNA accumulation.Thus,activation of MAPK-mediated immunity by NbPLDa1-derived PA is a common strategy employed by hosts to counteract positive-strand RNA virus infection.

Plant and animal positive-sense single-stranded RNA viruses encode small proteins important for viral infection in their negative-sense strand

Positive-sense single-stranded RNA(+ssRNA)viruses,the most abundant viruses of eukaryotes in nature,require the synthesis of negative-sense RNA(-RNA)using their genomic(positive-sense)RNA(+RNA)as a template for replication.Based on current evidence,viral proteins are translated via viral+RNAs,whereas-RNA is considered to be a viral replication intermediate without coding capacity.Here,we report that plant and animal+ssRNA viruses contain small open reading frames(ORFs)in their-RNA(reverse ORFs[rORFs]).Using turnip mosaic virus(TuMV)as a model for plant+ssRNA viruses,we demonstrate that small proteins encoded by rORFs display specific subcellularlocalizations,and confirm the presence of rORF2 in infected cells through mass spectrometry analysis.The protein encoded by TuMV rORF2 forms punctuate granules that are localized in the perinuclear region and co-localized with viral replication complexes.The rORF2 protein can directly interact with the viral RNA-dependent RNA polymerase,and mutation of rORF2 completely abolishes virus infection,whereas ectopic expression of rORF2 rescues the mutant virus.Furthermore,we show that several rORFs in the-RNA of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)have the ability to suppress type l interferon production and facilitate the infection of ve-sicular stomatitis virus.In addition,we provide evidence that TuMV might utilize internal ribosome entry sites to translate these small rORFs.Taken together,these findings indicate that the-RNA of+ssRNA vi-ruses can also have the coding capacity and that small proteins encoded therein play critical roles in viral infection,revealing a viral proteome larger than previously thought.

The host-targeting compound peruvoside has a broad-spectrum antiviral activity against positive-sense RNA viruses

Positive-sense RNA viruses modify intracellular calcium stores,endoplasmic reticulum and Golgi apparatus(Golgi)to generate membranous replication organelles known as viral factories.Viral factories provide a conducive and substantial enclave for essential virus replication via concentrating necessary cellular factors and viral proteins in proximity.Here,we identified the vital role of a broadspectrum antiviral,peruvoside in limiting the formation of viral factories.Mechanistically,we revealed the pleiotropic cellular effect of Src and PLC kinase signaling via cyclin-dependent kinase 1 signaling leads to Golgi-specific brefeldin A-resistance guanine nucleotide exchange factor 1(GBF1)phosphorylation and Golgi vesiculation by peruvoside treatment.The ramification of GBF1 phosphorylation fosters GBF1 deprivation consequentially activating downstream antiviral signaling by dampening viral factories formation.Further investigation showed signaling of ERK1/2 pathway via cyclin-dependent kinase 1 activation leading to GBF1 phosphorylation at Threonine 1337(T1337).We also showed 100%of protection in peruvoside-treated mouse model with a significant reduction in viral titre and without measurable cytotoxicity in serum.These findings highlight the importance of dissecting the broad-spectrum antiviral therapeutics mechanism and pave the way for consideration of peruvoside,host-directed antivirals for positive-sense RNA virus-mediated disease,in the interim where no vaccine is available.

Cucurbit[7]uril as a Broad-Spectrum Antiviral Agent against Diverse RNA Viruses

The emergence and re-emergence of RNA virus outbreaks highlight the urgent need for the development of broadspectrum antivirals.Polyamines are positively-charged small molecules required for the infectivity of a wide range of RNA viruses,therefore may become good antiviral targets.Cucurbit[7]uril(CB[7]),a synthetic macrocyclic molecule,which can bind with amine-based organic compounds with high affinity,has been shown to regulate bioactive molecules through competitive binding.In this study,we tested the antiviral activity of CB[7]against diverse RNA viruses,including a panel of enteroviruses(i.e.human enterovirus A71,coxsackievirus A16,coxsackievirus B3,and echovirus 11),some flaviviruses(i.e.dengue virus and Zika virus),and an alphavirus representative Semliki forest virus.CB[7]can inhibit virus replications in a variety of cell lines,and its mechanism of action is through the competitive binding with polyamines.Our findings not only for the first time provide evidence that CB[7]can be a promising broad-spectrum antiviral agent,but more importantly,offer a novel therapeutic strategy to fight against RNA viruses by supramolecular sequestration of polyamines.

CD97 negatively regulates the innate immune response against RNA viruses by promoting RNF125-mediated RIG-I degradation

The G protein-coupled receptor ADGRE5(CD97)binds to various metabolites that play crucial regulatory roles in metabolism.However,its function in the antiviral innate immune response remains to be determined.In this study,we report that CD97 inhibits virus-induced type-I interferon(IFN-I)release and enhances RNA virus replication in cells and mice.CD97 was identified as a new negative regulator of the innate immune receptor RIG-I,and RIG-1 degradation led to the suppression of the IFN-I signaling pathway.Furthermore,overexpression of CD97 promoted the ubiquitination of RIG-I,resulting in its degradation,but did not impact its mRNA expression.Mechanistically,CD97 upregulates RNF125 expression to induce RNF125-mediated RIG-I degradation via K48-linked ubiquitination at Lys181 after RNA virus infection.Most importantly,CD97-deficient mice are more resistant than wild-type mice to RNA virus infection.We also found that sanguinarine-mediated inhibition of CD97 effectively blocks VSV and SARS-CoV-2 replication.These findings elucidate a previously unknown mechanism through which CD97 negatively regulates RIG-I in the antiviral innate immune response and provide a molecular basis for the development of new therapeutic strategies and the design of targeted antiviral agents.

Cross-sectional evaluation of circulating hepatitis B virus RNA and DNA: Different quasispecies?

BACKGROUND Different forms of pregenomic and other hepatitis B virus(HBV)RNA have been detected in patients’sera.These circulating HBV-RNAs may be useful for monitoring covalently closed circular DNA activity,and predicting hepatitis B eantigen seroconversion or viral rebound after nucleos(t)ide analog cessation.Data on serum HBV-RNA quasispecies,however,is scarce.It is therefore important to develop methodologies to thoroughly analyze this quasispecies,ensuring the elimination of any residual HBV-DNA.Studying circulating HBV-RNA quasispecies may facilitate achieving functional cure of HBV infection.AIM To establish a next-generation sequencing(NGS)methodology for analyzing serum HBV-RNA and comparing it with DNA quasispecies.METHODS Thirteen untreated chronic hepatitis B patients,showing different HBV-genotypes and degrees of severity of liver disease were enrolled in the study and a serum sample with HBV-DNA>5 Log10 IU/mL and HBV-RNA>4 Log10 copies/mL was taken from each patient.HBV-RNA was treated with DNAse I to remove any residual DNA,and the region between nucleotides(nt)1255-1611 was amplified using a 3-nested polymerase chain reaction protocol,and analyzed with NGS.Variability/conservation and complexity was compared between HBV-DNA and RNA quasispecies.RESULTS No HBV-DNA contamination was detected in cDNA samples from HBV-RNA quasispecies.HBV quasispecies complexity showed heterogeneous behavior among patients.The Rare Haplotype Load at 1%was greater in DNA than in RNA quasispecies,with no statistically significant differences(P=0.1641).Regarding conservation,information content was equal in RNA and DNA quasispecies in most nt positions[218/357(61.06%)].In 102 of the remaining 139(73.38%),HBV-RNA showed slightly higher variability.Sliding window analysis identified 4 hyper-conserved sequence fragments in each quasispecies,3 of them coincided between the 2 quasispecies:nts 1258-1286,1545-1573 and 1575-1604.The 2 hyper-variable sequence fragments also coincided:nts 1311-1344 and 1461-1485.Sequences between nts 1519-1543 and 1559-1587 were only hyper-conserved in HBV-DNA and RNA,respectively.CONCLUSION Our methodology allowed analyzing HBV-RNA quasispecies complexity and conservation without interference from HBV-DNA.Thanks to this,we have been able to compare both quasispecies in the present study.

Construction Strategy and Affecting Factors of Positive-Strand RNA Virus Infectious Clone

Construction of infectious clones by full-length cDNA is basic and key for recovering RNA virus and is core of reverse genetics.In this article,basic consideration and key technology were viewed and factors affecting infectivity of clones were also summarized.Some research advances were briefly introduced about positive-strand RNA viruses infectious clones.Finally,this article also reviewed the application of infectious clones.

Detection of Replicative Form of HCV RNA in Peripheral Blood Leukocytes and Its Clinical Significance

Nested RT-PCR, done by using degenerated primer pair, was used to detect hepatitis C virus RNA (HCV RNA) in serum, plasma, liver and peripheral blood mononuclear cells (PBMC) of 30 patients with acute and chronic posttransfusion hepatitis C and 7 asymptomatic anti-HCV positive subjects. The results showed that the percentages of both the plus and minus strands of HCV RNA in PBMC of the patients with chronic hepatitis C was significantly higher than that with acute hepatitis C and asymptomatic anti-HCV positive subjects ( P<0.05-0.001). In 17 patients who were subjected to biopsy, the positive rate of the both strands of HCV RNA in PBMC of the patients with AH was lower than that of CAH ( P<0.05). In serum and plasma of all 37 cases, the minus strand of HCV RNA was not detected. Both plus and minus strands in liver of one patient with AH were positive , but the minus strand in PBMC negative. In 6 patients with CAH whose both strands in liver were positive,Both strands in PBMC in 5 patients were also found. The present data confirmed that PBMC of the patients with hepatitis C were infected by HCV and the longer the infection time, the bigger the possibility of PBMC infection by HCV. The patients with active liver disease (CAH) had higher positive rate of minus strands of HCV RNA in PBMC. The results suggested that HCV may not only infect PBMC but also replicate in PBMC , and that the occurrence of minus strand of HCV RNA is associated with activity of liver disease.

The expression of foreign gene under the control of cauliflower mosaic virus 35s RNA promoter

The promoter region of cauliflower mosaic virus (CaMV) 35s RNA was employed to construct an intermediate expression vector which can be used in Ti plasmid system of Agro-bacterium tumefaciens. The original plasmid, which contains a polylinker between CaMV 35s RNA and its 3' termination signal in pUC18 was modified to have another antibiotic resistance marker (kanamycin resistance gene Kmr) to facilitate the selection of recombinant with Ti plasmid. Octopine synthase (ocs) structural gene was inserted into this vector downstream of CaMV 35s RNA promoter. This chimaeric gene was introduced into integrative Ti plasmid vector pGV3850, and then transformed into Nicotiana tobaccum cells. A binary plasmid vector was also used to introduce the chimaeric gene into tobacco cells. In both cases, the expression of ocs gene was demonstrated. The amount of oc-topine was much more than the nopaline synthesized by no-paline synthase (nos) gene transferred at the same time with Ti plasmid vector. This demonstrated that CaMV 35s RNA promoter is stronger in transcriptional function than the promoter of nos in tobacco cells.

Emerging perspectives on RNA virus-mediated infections:from pathogenesis to therapeutic interventions

RNA viruses continue to pose significant threats to global public health,necessitating a profound understanding of their pathogenic mechanisms and the development of effective therapeutic interventions.This manuscript provides a comprehensive overview of emerging perspectives on RNA virus-mediated infections,spanning from the intricate intricacies of viral pathogenesis to the forefront of innovative therapeutic strategies.A critical exploration of antiviral drugs sets the stage,highlighting the diverse classes of compounds that target various stages of the viral life cycle,underscoring the ongoing efforts to combat viral infections.Central to this discussion is the exploration of RNA-based therapeutics,with a spotlight on messenger RNA(mRNA)-based approaches that have revolutionized the landscape of antiviral interventions.Furthermore,the manuscript delves into the intricate world of delivery systems,exploring innovative technologies designed to enhance the efficiency and safety of mRNA vaccines.By analyzing the challenges and advancements in delivery mechanisms,this review offers a roadmap for future research and development in this critical area.Beyond conventional infectious diseases,the document explores the expanding applications of mRNA vaccines,including their promising roles in cancer immunotherapy and personalized medicine approaches.This manuscript serves as a valuable resource for researchers,clinicians,and policymakers alike,offering a nuanced perspective on RNA virus pathogenesis and the cutting-edge therapeutic interventions.By synthesizing the latest advancements and challenges,this review contributes significantly to the ongoing discourse in the field,driving the development of novel strategies to combat RNA virus-mediated infections effectively.

Characterization and function of Tomato yellow leaf curl virus-derived small RNAs generated in tolerant and susceptible tomato varieties

supported by the Specialized Research Fund for the Doctoral Program of Higher Education of China （20134320120013）;the Natural Science Foundation of Hunan Province, China （14JJ3095）

Correlation between HBeAg and Hepatitis B Virus DNA and RNA Levels in Diverse Liver Disease Cohorts

Objective:To investigate the disparities and associations between HBV DNA and HBV RNA in various liver disease groups with respect to HBeAg status.Methods:Between September 2020 and September 2023,90 patients diagnosed with chronic hepatitis B(CHB),74 patients diagnosed with liver cirrhosis(LC),and 102 patients diagnosed with hepatocellular carcinoma(HCC)from the Department of Gastroenterology or Infection at the First Affiliated Hospital of Xi’an Jiaotong University were selected.HBV DNA,HBV RNA,and HBeAg quantitative tests were conducted using serum samples from the same patients.Results:In the three groups of cases,the HBV RNA load was higher when HBeAg was positive than when HBeAg was negative,and this difference was statistically significant.Only in the HCC group was the HBV DNA load significantly higher when HBeAg was positive than when HBeAg was negative.Additionally,there was a positive correlation between HBV DNA and HBV RNA regardless of HBeAg status.Conclusion:During HBeAg conversion,HBV RNA demonstrates a more sensitive response than HBV DNA.As CHB progresses to LC or HCC,HBV RNA exhibits better diagnostic value than HBV DNA.

Clinical Value of Hepatitis B Virus RNA Detection in Patients with Chronic Hepatitis B Infection

Objective:To study the clinical value of hepatitis B virus pregenomic RNA(HBV-pgRNA)detection in the treatment of hepatitis B.Methods:60 patients with hepatitis B were included in the study.Serum HBV-pgRNA and HBV DNA levels in different phases of infection and during treatment were detected,and serum hepatitis B surface antigen(HbsAg)titer was detected by chemiluminescent immunoassay.DNA was extracted from liver biopsy tissue,and covalently closed circular DNA was detected to predict the therapeutic value in patients.Results:At the initial stage of treatment,the level of HBV-pgRNA in phase I,II,III,and IV showed a gradual decrease.Comparing the levels of HBV-pgRNA before and after treatment,we found that the level of HBV-pgRNA was significantly lower after treatment(P<0.05).Among the indicators for predicting HBsAg seroconversion,the accuracy of HBV-pgRNA level was 85.0%(51/60).Conclusion:The clinical value of HBV-pgRNA detection in the treatment of hepatitis B is high.

CRISPR/CasRx-mediated resistance to Soybean mosaic virus in soybean

Soybean mosaic virus(SMV),an RNA virus,is the most common and destructive pathogenic virus in soybean fields.The newly developed CRISPR/Cas immune system has provided a novel strategy for improving plant resistance to viruses;hence,this study aimed to engineer SMV resistance in soybean using this system.Specifically,multiple sgRNAs were designed to target positive-and/or negative-sense strands of the SMV HC-Pro gene.Subsequently,the corresponding CRISPR/CasRx vectors were constructed and transformed into soybeans.After inoculation with SMV,39.02%,35.77%,and 18.70%of T_(1)plants were confirmed to be highly resistant(HR),resistant(R),and mildly resistant(MR)to SMV,respectively,whereas only 6.50%were identified as susceptible(S).Additionally,qRT-PCR and DAS-ELISA showed that,both at 15 and 30 d post-inoculation(dpi),SMV accumulation significantly decreased or was even undetectable in HR and R plants,followed by MR and S plants.Additionally,the expression level of the CasRx gene varied in almost all T_(1)plants with different resistance level,both at 15 and 30 dpi.Furthermore,when SMV resistance was evaluated in the T_(2)generation,the results were similar to those recorded for the T_(1)generation.These findings provide new insights into the application of the CRISPR/CasRx system for soybean improvement and offer a promising alternative strategy for breeding for resistance to biotic stress that will contribute to the development of SMV-immune soybean germplasm to accelerate progress towards greater soybean crop productivity.

Is there a need for universal double reflex testing of HBsAg-positive individuals for hepatitis D infection?

Hepatitis D virus(HDV)can infect HBsAg-positive individuals,causing rapid fibrosis progression,early decompensation,increased hepatocellular carcinoma risk,and higher mortality than hepatitis B virus(HBV)mono-infection.Most countries lack high-quality HDV prevalence data,and the collection techniques employed often bias published data.In recent meta-analyses,HDV prevalence in HBsAg-positive patients reaches 5%-15%and is even significantly higher in endemic areas.Since HBV vaccination programs were implemented,HDV prevalence has decreased among younger populations.However,owing to immigrant influx,it has increased in some Western countries.The current practice of HDV screening in HBsAg-positive individuals is stepwise,based on physician’s discretion,and limited to at-risk populations and may require numerous visits.Double reflex testing,which includes anti-HDV testing in all HBsAg-positive individuals and then HDV RNA testing for anti-HDV-positive ones,is uncommon.Reflex testing can identify more HDV infection cases and link identified patients to further care and follow-up.Moreover,laboratory-based double reflex screening is less biased than physician-led testing.Therefore,health-care providers should learn about reflex testing,and federal and provincial hepatitis control programs should implement laboratory-based double reflex testing to obtain reliable HDV prevalence estimates.The test’s cost-effectiveness depends on the number of HBV-positive patients screened to identify one HDV-positive patient.Such testing may be viable in areas with low HBsAg but high HDV prevalence.However,its economic impact on areas with low HDV prevalence needs further study.

Study of Fractional Order Dynamical System of Viral Infection Disease under Piecewise Derivative

This research aims to understand the fractional order dynamics of the deadly Nipah virus(NiV)disease.We focus on using piecewise derivatives in the context of classical and singular kernels of power operators in the Caputo sense to investigate the crossover behavior of the considered dynamical system.We establish some qualitative results about the existence and uniqueness of the solution to the proposed problem.By utilizing the Newtonian polynomials interpolation technique,we recall a powerful algorithm to interpret the numerical findings for the aforesaid model.Here,we remark that the said viral infection is caused by an RNA type virus which can transmit from animals and also from an infected person to person.Fruits bats which are also known as flying foxes are one of the sources of transmission of NiV disease.Here in this work,we investigate its transmission mechanism through some new concepts of fractional calculus for further analysis and prediction.We present the approximate results for different compartments using different fractional orders.By using the piecewise derivative concept,we detect the crossover ormulti-steps behavior in the transmission dynamics of the mentioned disease.Therefore,the considered form of the derivative is used to deal with problems exhibiting crossover behaviors.

Desperately seeking hepatitis C virus

Spanish investigators described recently the so-called occult hepatitis C virus (HCV) infection, emphasizing the detection of genomic and antigenomic HCV RNA strands in liver and peripheral blood mononuclear cells. Therefore, the persistence of viral replication in occult HCV infection should be considered as a putative source of infection among family members and patients undergoing invasive procedures, transfusion or transplantation. Additionally, the most worrisome finding is that an occult HCV infection may persist in patients with sustained virological response.

Hepatitis D virus dual-infection among Chinese hepatitis B patient related to hepatitis B surface antigen,hepatitis B virus DNA and age

The screening practices for hepatitis D virus(HDV)are diverse and nonstandardized worldwide,and the exact prevalence of HDV is uncertain.AIM To estimate HDV prevalence and investigate viral marker quantity trends in patients with hepatitis D.METHODS We collected 5594 serum samples from patients with hepatitis B in Jilin Province,China(3293 males and 2301 females,age range of 2 to 89 years).We then conducted tests for hepatitis B surface antigen(HBsAg),hepatitis B Virus(HBV)DNA,anti-hepatitis D antigen(HDAg),and HDV RNA.RESULTS We found that the prevalence of anti-HDAg and HDV RNA among hepatitis B patient were 3.6%(3.2-4.2%)and 1.2%(0.9-1.5%),respectively,87.69%of hepatitis D patients were 51-70 years old.HDV infection screening positive rate of patients with HBV DNA levels below 2000 IU/mL(2.0%)was higher than those above 2000 IU/mL(0.2%).Among anti-HDAg positive patients,the HDV RNA positive rate was positively correlated with the HBsAg level and anti-HDAg level.There was a weak correlation between HBsAg and anti-HDAg levels among hepatitis D patients.CONCLUSION Our study highlights the importance of considering multiple factors when assessing the severity of HDV infection,comprehensive evaluation of patients’clinical and laboratory parameters is necessary for proper diagnosis and treatment.

Co-treatment with pegylated interferon alfa-2a and entecavir for hepatitis D: a randomized trial

AIM: To investigate the efficacy of pegylated interferon alfa(PEG-IFNα) therapy with and without entecavir in patients with chronic hepatitis D. METHODS: Forty hepatitis D virus(HDV) RNA positive patients were randomized to receive either PEG-IFNα-2a 180 μg weekly in combination with entecavir 0.5 mg daily(n = 21) or PEG-IFNα alone(n =19). Patients who failed to show 2 log reduction in HDV RNA level at 24 wk of treatment, or had detectable HDV RNA at 48 wk of therapy were considered as treatment failure. Treatment was continued for 72 wk in the rest of the patients. All the patients were followed for 24 wk post treatment. Intention to treat analysis was performed.RESULTS: The mean age of the patients was 26.7 ± 6.8 years, 31 were male. Two log reduction in HDV RNA levels at 24 wk of therapy was achieved in 9(43%) patients receiving combination therapy and 12(63%) patients receiving PEG-IFNα alone(P = 0.199). Decline in hepatitis B surface antigen(HBs Ag) levels was insignificant. At the end of treatment, HDV RNA was negative in 8 patients(38%) receiving combination therapy and 10 patients(53%) receiving PEG-IFNα-2a alone. Virological response persisted in 7(33%) and 8(42%) patients, respectively at the end of the 24 wk follow-up period. One responder patient in the combination arm lost HBs Ag and became hepatitis B surface antibody positive. Six out of 14 baseline hepatitis B e antigen reactive patients seroconverted and four of these seroconverted patients had persistent HDV RNA clearance.CONCLUSION: Administration of PEG-IFNα-2a with or without entecavir, resulted in persistent HDV RNA clearance in 37% of patients. The addition of entecavir did not improve the overall response.