Hepatitis C virus reinfection after liver transplantation: Is there a role for direct antiviral agents?

Recurrence of hepatitis C virus(HCV)infection following liver transplantation(LT)is almost universal and can accelerate graft cirrhosis in up to 30%of patients.The development of effective strategies to treat or prevent HCV recurrence after LT remains a major challenge,considering the shortage of donor organs and the accelerated progression of HCV in LT recipients.Standard antiviral therapy with pegylated-interferon plus ribavirin is the current treatment of choice for HCV LT recipients,even though the combination is not as effective as it is in immunocompetent patients.A sustained virological response in the setting of LT improves patient and graft survival,but this is only achieved in 30%-45%of patients and the treatment is poorly tolerated.To improve the efficacy of pre-and post-transplant antiviral therapy,a new class of potent direct-acting antiviral agents (DAAs)has been developed.The aim of this review is to summarize the use of DAAs in LT HCV patients.PubMed,Cochrane Library,MEDLINE,EMBASE,Web of Science and clinical trial databases were searched for this purpose.To date,only three clinical studies on the topic have been published and most of the available data are in abstract form.Although a moderately successful early virological response has been reported,DAA treatment regimens were associated with severe toxicity mitigating their potential usefulness.Moreover,the ongoing nature of data,the lack of randomized studies,the small number of enrolled patients and the heterogeneity of these studies make the results largely anecdotal and questionable.In conclusion,large welldesigned clinical studies on DAAs in HCV LT patients are required before these drugs can be recommended after transplantation.

Response rates to direct antiviral agents among hepatitis C virus infected patients who develop hepatocellular carcinoma following direct antiviral agents treatment

Aim:Patients with chronic hepatitis C virus(HCV)infection who develop hepatocellular carcinoma(HCC)soon after treatment with direct antiviral agents(DAA)may have been harboring hitherto hidden tumors.If this were true,they should have a lower sustained viral response(SVR)rate,since active HCC hampers DAA efficacy.We aimed to verify this hypothesis.Methods:We included all patients who attended an HCV clinic,provided that they:(1)had no previous history of HCC;(2)had received at least one DAA dose;and(3)had been followed-up clinically and ultrasonographically for at least six months after concluding DAA.Results:The study population included n=789 patients(55%males,median age 62 years).A median of 9.3 months(8.8-11.9)after concluding DAA,n=19(2.4%)patients were discovered to harbor HCC.In comparison to all others,patients with HCC were more commonly male(84%vs.54%,P=0.009),obese(47%vs.17%,P=0.002),and cirrhotic(95%vs.35%,P<0.001)and had less commonly achieved an SVR(68%vs.98%,P<0.001).Moreover,they had a trend for being less commonly treatment na?ve(58%vs.67%,P=0.051).Based on multivariate analysis, ;the independent predictors of HCC were male sex(P=0.031),cirrhosis(P=0.004),obesity(P=0.006),and failure to achieve an SVR(P<0.001).Conclusion:Lack of achieving SVR is a strong independent predictor of development of HCC early after treatment of hepatitis C with DAA.Treatment failure should further alert clinicians to the possibility of this dreadful complication.

Hepatitis C virus cures after direct acting antiviral-related drug-induced liver injury: Case report

The United States Food and Drug Administration recently warned that the direct acting antiviral(DAA) combination hepatitis C virus(HCV) treatment of Paritaprevir, Ombitasvir, Dasabuvir, Ritonavir, and Ribavirin(PODr + R) can cause severe liver injury in patients with advanced liver disease. Drug induced liver injury was observed in a small number of patients with decompensated cirrhosis treated with other DAAs, but has not been reported in patients with compensated cirrhosis. We report a case of a 74-year-old woman with chronic HCV and Child-Pugh class A cirrhosis(compensated cirrhosis) treated with PODr + R. The patient presented on day 14 of PODr + R therapy with jaundice and new-onset ascites. Her total bilirubin level increased to 23 mg/dL and international normalized ratio rose to 1.65, while aminotransferase levels remained relatively stable. Hepatitis C treatment was discontinued on day 24 and she gradually recovered. Follow-up testing showed that she achieved a sustained virologic response. In conclusion, hepatic decompensation developed within two weeks of starting treatment withPODr + R in a patient with Child-Pugh class A cirrhosis and was characterized by jaundice and ascites with stable aminotransferase levels. Careful monitoring is warranted in patients with HCV-related cirrhosis treated with PODr + R.

Hepatitis C and double-hit B cell lymphoma successfully treated by antiviral therapy

B cells lymphoma is one of the most challenging extrahepatic manifestations of hepatitis C virus(HCV). Recently, a new kind of B-cell lymphoma, named doublehit B(DHL), was characterized with an aggressive clinical course whereas a potential association with HCV was not investigated. The new antiviral direct agents(DAAs) against HCV are effective and curative in the majority of HCV infections. We report the first case, to our knowledge, of DHL and HCV-infection successfully treated by new DAAs. According to our experience, a DHL must be suspected in case of HCV-related lymphoma, and an early diagnosis could direct towards a different hematological management because a worse prognosis might be expected. A possible effect of DAAs on DHL regression should be investigated, but eradicating HCV would avoid life-threatening reactivation of viral hepatitis during pharmacological immunosuppression in oncohaematological diseases.

Direct-acting Antiviral Agents Resistance-associated Polymorphisms in Chinese Treatment-na（i）ve Patients Infected with Genotype 1b Hepatitis C Virus

Background：It has been reported that several baseline polymorphisms of direct-acting antivirals （DAAs） agents resistance-associated variants （RAVs） would affect the treatment outcomes of patients chronically infected with hepatitis C virus （CHC）.The aim of this study is to investigate the prevalence of DAAs RAVs in treatment-na（i）ve GT1b CHC patients.Methods：Direct sequencing and ultra-deep sequencing of the HCV NS3,NS5A,and NS5B gene were performed in baseline serum samples of treatment-ha（i）ve patients infected with genotype lb hepatitis C virus （HCVs）.Results：One hundred and sixty CHC patients were studied.Complete sequence information was obtained for 145 patients （NS3）,148 patients （NS5A）,and 137 patients （NS5B）.Treatment-failure associated variants of DAAs were detected：56.6％ （82/145） of the patients presented S122G for simeprevir （NS3 protease inhibitor）;10.1％ （14/148） of the patients presented Y93H for daclatasvir and ledipasvir （NS5A protein inhibitors）;94.2％ （129/137） of the patients presented C316N for sofosbuvir （NS5B polymerase inhibitor）.Nearly,all of the DAAs RAVs detected by ultra-deep sequencing could be detected by direct sequencing.Conclusions：The majority of genotype lb CHC patients in China present a virus population carrying HCV DAAs RAVs.Pretreatment sequencing of HCV genome might need to be performed when patients infected with GTlb HCV receiving DAAs-containing regimens in China.Population sequencing would be quite quantified for the work.

Progress and challenges in the comprehensive management of chronic viral hepatitis: Key ways to achieve the elimination

Chronic viral hepatitis is a significant health problem throughout the world,which already represents high annual mortality.By 2040,chronic viral hepatitis due to virus B and virus C and their complications cirrhosis and hepatocellular carcinoma will be more deadly than malaria,vitellogenesis-inhibiting hormone,and tuberculosis altogether.In this review,we analyze the global impact of chronic viral hepatitis with a focus on the most vulnerable groups,the goals set by the World Health Organization for the year 2030,and the key points to achieve them,such as timely access to antiviral treatment of direct-acting antiviral,which represents the key to achieving hepatitis C virus elimination.Likewise,we review the strategies to prevent transmission and achieve control of hepatitis B virus.Finally,we address the impact that the coronavirus disease 2019 pandemic has had on implementing elimination strategies and the advantages of implementing telemedicine programs.

Concise review: Interferon-free treatment of hepatitis C virus-associated cirrhosis and liver graft infection

Chronic hepatitis C is a major reason for development of cirrhosis and hepatocellular carcinoma and a leading cause for liver transplantation. The development of direct-acting antiviral agents lead to(pegylated) interferon-alfa free antiviral therapy regimens with a remarkable increase in sustained virologic response(SVR) rates and opened therapeutic options for patients with advanced cirrhosis and liver graft recipients. This concise review gives an overview about most current prospective trials and cohort analyses for treatment of patients with liver cirrhosis and liver graft recipients. In patients with compensated cirrhosis Child-Pugh-Turcotte(CTP) class A, all approved agents are safe and SVR rates do not significantly differ from patients without cirrhosis in general. In patients with decompensated cirrhosis CTP class B or C, daclastasvir, ledipasvir, velpatasvir, and sofosbuvir are approved, and SVR rates higher than 90% can be achieved. Especially for patients with a model of end stage liver disease score higher than 15 and therefore eligible for liver transplantation, data is scarce. Reported SVR rates in patients with cirrhosis CTP class C are lower compared to patients with a less severe liver disease. In liver transplant recipients with a maximum of CTP class A, SVR rates are comparable to patients without LT. Patients with decompensated graft cirrhosis should be treated on an individual basis.

Hepatitis C in injection drug users: It is time to treat

Injection drug users(IDUs)are at risk of hepatitis C virus(HCV)infection,due to needle and syringe sharing.Chronic HCV infection is a major cause of liver-related morbidity and mortality but can be cured with antiviral treatment leading to sustained viral response(SVR).It is well demonstrated that,when close cooperation between specialists in drug addiction and psychiatrists is assured,patients on maintenance treatment with methadone/buprenorphine can be treated for HCV with response rate,tolerability and side effects similar to those reported in non-IDUs.Current guidelines recommend that active injection drug use should not exclude patients from HCV treatment,but many services remain reluctant to treat IDUs.No significant pharmacodynamic interactions were reported between approved direct anti-viral agents(DAAs)and buprenorphine or methadone.Dose adjustments are not recommended;therefore DAAs appear to be the"perfect"therapy for patients taking opiate substitutive therapy.These suggestions have been recently recognized by the European Association for the Study of the Liver(EASL)and included in EASL Recommendations on Treatment of Hepatitis C 2016.Guidelines confirm that HCV treatment for IDUs should be considered on an individualized basis and delivered within a multidisciplinary team setting;a history of intravenous drug use and recent drug use at treatment initiation are not associated with reduced SVR and decisions to treat must be made on a case-by-case basis.

Polymorphisms and resistance mutations of hepatitis C virus on sequences in the European hepatitis C virus database

AIM To evaluate the occurrence of resistant mutations in treatment-na?ve hepatitis C virus(HCV) sequences deposited in the European hepatitis C virus database(euH CVdb). METHODS The sequences were downloaded from the eu HCVdb(https://euhcvdb.ibcp.fr/eu HCVdb/). The search was performed for full-length NS3 protease, NS5 A and NS5 B polymerase sequences of HCV, separated by genotypes 1a, 1b, 2a, 2b and 3a, and resulted in 798 NS3, 708 NS5 A and 535 NS5 B sequences from HCV genotypes1a, 1b, 2a, 2b and 3a, after the exclusion of sequences containing errors and/or gaps or incomplete sequences, and sequences from patients previously treated with direct antiviral agents(DAA). The sequence alignment was performed with MEGA 6.06 MAC and the resulting protein sequences were then analyzed using the BioE dit 7.2.5. for mutations associated with resistance. Only positions that have been described as being associated with failure in treatment in in vivo studies, and/or as conferring a more than 2-fold change in replication in comparison to the wildtype reference strain in in vitro phenotypic assays were included in the analysis.RESULTS The Q80 K variant in the NS3 gene was the most prevalent mutation, being found in 44.66% of subtype 1a and 0.25% of subtype 1b. Other frequent mutations observed in more than 2% of the NS3 sequences were: I170V(3.21%) in genotype 1a, and Y56F(15.93%), V132I(23.28%) and I170V(65.20%) in genotype 1b. For the NS5 A, 2.21% of the genotype 1a sequences have the P58 S mutation, 5.95% of genotype 1b sequences have the R30 Q mutation, 15.79% of subtypes 2a sequences have the Q30 R mutation, 23.08% of subtype 2b sequences have a L31 M mutation, and in subtype 3a sequences, 23.08% have the M31 L resistant variants. For the NS5 B, the V321 L RAV was identified in 0.60% of genotype 1a and in 0.32% of genotype 1b sequences, and the N142 T variant was observed in 0.32% of subtype 1b sequences. The C316 Y, S556 G, D559 N RAV were identified in 0.33%, 7.82% and 0.32% of genotype 1b sequences, respectively, and were not observed in other genotypes.CONCLUSION HCV mutants resistant to DAAs are found in low frequency, nevertheless they could be selected and therapy could fail due resistance substitutions in HCV genome.

Pre-treatment prediction of response to peginterferon plus ribavirin in chronic hepatitis C genotype 3

AIM: To evaluate pre-treatment factors associated with sustained virological response(SVR) in patients with hepatitis C virus(HCV) genotype 3 treated with peginterferon and ribavirin(RBV). METHODS: We retrospectively analyzed treatment naive, mono-infected HCV genotype 3 patients treated with peginterferon and RBV. Exclusion criteria included presence of other liver disease, alcohol consumption and African American or Asian ethnicity. The variables collected and compared between patients who achieved an SVR and patients who did not were as follows: gender, age, fibrosis stage, diabetes, body mass index,steatosis, INFL3 polymorphism, pre-treatment HCVRNA, type of peginterferon, RBV dose and adherence. RESULTS: A total of 107 patients treated between June, 2004 and March, 2013 were included. Mean treatment duration was 25.1(± 1.8) wk. Overall, 58%(62/107) of the patients achieved an SVR and 42%(45/107) did not. In the multivariate logistic regression analysis, pre-treatment HCV-RNA ≥ 600000 UI/m L(OR = 0.375, 95%CI: 0.153-0.919, P = 0.032) and advanced fibrosis(OR = 0.278, 95%CI: 0.113-0.684,P = 0.005) were significantly associated with low SVR rates. In patients with pre-treatment HCV-RNA ≥600000 UI/m L and advanced fibrosis, the probability of achieving an SVR was 29%(95%CI: 13.1-45.2).In patients with pre-treatment HCV-RNA < 600000UI/m L and mild to moderate fibrosis, the probability of achieving an SVR was 81%(95%CI: 68.8-93.4).CONCLUSION: In patients with HCV genotype 3infections the presence of advance fibrosis and high pre-treatment viral load might be associated with poor response to peginterferon plus RBV. These patients could benefit the most from new direct antiviral agentsbased regimes.

Impact of hepatitis C oral therapy in portal hypertension

Chronic hepatitis C is a leading cause of morbidity and mortality, mainly related to fibrosis/cirrhosis and portal hypertension. Direct antiviral agents are highly effective and safe and can now cure > 90% of the patients. Sustained viral response (SVR) after interferon-based regimens has been associated with improvement in liver function, fibrosis and portal hypertension in a significant proportion of patients, although a point of no return seems to exist from which viral elimination is no longer capable of preventing portal hypertension progression and liver decompensation. Indeed, although SVR is associated with improvement of hepatic venous pressure gradients and therefore a decreased risk of de novo esophageal varices, several studies show that viral clearance does not eliminate the risk of variceal progression, liver decompensation and death in patients with pre-established portal hypertension. Although evidence about the effects of direct antiviral agents (DAAs) on clinically significant outcomes is still scarce and with short follow-up, DAAs can decrease the burden of the disease if patients are timely treated before significant fibrosis and portal hypertension develops. Studies with longer follow-up are waited to establish the real magnitude of hepatitis C treatment on portal hypertension. Future studies should also focus on predictors of portal hypertension resolution since it can influence management and avoid unnecessary monitoring

Hepatitis C: Problems to extinction and residual hepatic and extrahepatic lesions after sustained virological response

Loss of follow-up or reinfections hinder the expectations of hepatitis C eradicationdespite the existence of highly effective treatments. Moreover, the elimination ofthe infection does not imply the reversion of those chronic alterations derivedfrom the previous infection by hepatitis C virus (HCV). This review analyzes therisk factors associated with loss to follow-up in diagnosis or treatment, and thepossibility of reinfection. Likewise, it assesses the residual alterations induced bychronic HCV infection considering the liver alterations (inflammation, fibrosis,risk of decompensation, hepatocellular carcinoma, liver transplantation) and, onthe other hand, the comorbidities and extrahepatic manifestations (cryoglobulinemia,non-Hodgkin lymphoma, peripheral insulin resistance, and lipid, boneand cognitive alterations). Peculiarities present in subjects coinfected with humanimmunodeficiency virus are analyzed in each section.

Interferon-free regimens in patients with hepatitis C infection and renal dysfunction or kidney transplantation

Treatment of patients with chronic kidney disease(CKD) and chronic hepatitis C(CHC) differs from that used in the general CHC population mostly when glomerular filtration rate(GFR) is below 30 m L/min, as sofosbuvir, the backbone of several current regimens, is officially contraindicated. Given that ribavirin free regimens are preferable in CKD, elbasvir/grazoprevir is offered in CHC patients with genotype 1 or 4 and ombitasvir/paritaprevir and dasabuvir in genotype 1b for 12 wk. Although regimens containing peginterferon with or without ribavirin are officially recommended for patients with CKD and genotype 2, 3, 5, 6, such regimens are rarely used because of their low efficacy and the poor safety and tolerance profile. In this setting, especially in the presence of advanced liver disease, sofosbuvirbased regimens are often used, despite sofosbuvir contraindication. It seems to have good overall safety with only 6% or 3.4% of CKD patients to discontinue therapy or develop serious adverse events without drug discontinuation. In addition, sustained virological response(SVR) rates with sofosbuvir based regimens in CKD patients appear to be comparable with SVR rates in patients with normal renal function. Treatment recommendations for kidney transplant recipients are the same with those for patients with CHC, taking into consideration potential drug-drug interactions and baseline GFR before treatment initiation. This review summarizes recent data on the current managementof CHC in CKD patients highlighting their strengths and weaknesses and determining their usefulness in clinical practice.

Retrospective study of the associations between hepatitis C virus infection and metabolic factors

AIMTo evaluate the bidirectional association between metabolic syndrome (MS) components and antiviral treatment response for chronic hepatitis C virus (HCV) infection. METHODSThis retrospective cohort study included 119 HCV + patients treated with pegylated-interferon-α and ribavirin. Metabolic characteristics and laboratory data were collected from medical records. Differences in baseline clinical and demographic risk factors between responders and non-responders were assessed using independent samples t-tests or χ2 tests. The effects of sustained viral response (SVR) to antiviral treatment on de novo impairments in MS components, including impaired fasting glucose (IFG) and type 2 diabetes mellitus (T2DM), were assessed using univariable and multivariable logistic regression analysis, while the effect of MS components on SVR was assessed using univariable logistic regression analysis. RESULTSOf the 119 patients, 80 (67%) developed SVR over the average 54 ± 13 mo follow-up. The cumulative risks for de novo T2DM and IFG were 5.07- (95%CI: 1.261-20.4, P = 0.022) and 3.87-fold higher (95%CI: 1.484-10.15, P = 0.006), respectively for non-responders than responders, when adjusted for the baseline risk factors age, sex, HCV genotype, high viral load, and steatosis. Post-treatment triglyceride levels were significantly lower in non-responders than in responders (OR = 0.27; 95%CI: 0.069-0.962, P = 0.044). Age and HCV genotype 3 were significantly different between responders and non-responders, and MS components were not significantly associated with SVR. Steatosis tended to attenuate SVR (OR = 0.596; 95%CI: 0.331-1.073, P = 0.08). CONCLUSIONSVR was associated with lower de novo T2DM and IFG incidence and higher triglyceride levels. Patients infected with HCV should undergo T2DM screening and antidiabetic treatment.

Opportunities for treatment of the hepatitis C virus-infected patient with chronic kidney disease

The prevalence of hepatitis C virus(HCV) infection amongst patients with chronic kidney disease(CKD) and end-stage renal disease exceeds that of the general population. In addition to predisposing to the development of cirrhosis and hepatocellular carcinoma, infection with HCV has been associated with extra-hepatic complications including CKD, proteinuria, glomerulonephritis, cryoglobulinemia, increased cardiovascular risk, insulin resistance, and lymphoma. With these associated morbidities, infection with HCV is not unexpectedly accompanied by an increase in mortality in the general population as well as in patients with kidney disease. Advances in the understanding of the HCV genome have resulted in the development of direct-acting antiviral agents that can achieve much higher sustained virologic response rates than previous interferon-based protocols. The direct acting antivirals have either primarily hepatic or renal metabolism and excretion pathways. This information is particularly relevant when considering treatment in patients with reduced kidney function. In this context, some of these agents are not recommended for use in patients with a glomerular filtration rate < 30 m L/min per 1.73 m^2. There are now Food and Drug Administration approved direct acting antiviral agents for the treatment of patients with kidney disease and reduced function. These agents have been demonstrated to be effective with sustained viral response rates comparable to the general population with good safety profiles. A disease that was only recently considered to be very challenging to treat in patients with kidney dysfunction is now curable with these medications.

Revolution in the diagnosis and management of hepatitis C virus infection in current era

Chronic hepatitis C virus(HCV)infection is a major global public health problem,particularly in developing part of the world.Significant advances have been made in the early diagnosis and treatment of the disease.Its management has been particularly revolutionized during the past two decades.In this review,we summarize the major advances in the diagnostic and management armamentarium for chronic HCV infection.The focus of the present review is on the newer directly acting anti-viral agents,which have revolutionized the management of chronic HCV infection.Management of uncomplicated chronic HCV infection and of specific complications and special at-risk populations of patients will be covered in detail.Despite the advent and approval of highly effective and well tolerable oral agents,still many challenges remain,particularly the affordability,the equitable distribution and access to later drugs.The World Health Organization aims to eliminate viral hepatitis including HCV by 2030 since its poses a major public health threat.There is an urgent need to ensure uniform and early access to diagnostic and therapeutic facilities throughout the world if the later goal has to be realized.

Antiviral therapy for ＂difficult-to-treat＂ hepatitis C virus-infected patients

Objective To review the updated research on direct antiviral agents （DAAs）-including regimens for hepatitis C virus （HCV）,and focus on ＂difficult-to-treat＂ HCV-infected patients.Data sources The literature concerning DAAs and hepatitis C cited in this review was collected from PubMed and Google Scholar databases published in English up to July 2013.Study selection Data from published articles regarding HCV and DAAs in clinical trials and in clinical use were identified and reviewed.Results It was recognized that some ＂difficult-to-treat＂ patients would still exist,even though stronger treatments using such as DAAs,including telaprevir and boceprevir,which lead to higher sustained virological response rates,are available.Such patients include those with advanced fibrosis/cirrhosis,elderly persons,children,HCV-human immunodeficiency virus co-infected patients,HCV-infected recipients,and so on.Conclusions Certain ＂difficult-to-treat＂ patients would still exist,even though stronger treatment is available.Although evidence from clinical trials is still lacking,interferon-sparing regimens could have stronger effects for eradicating HCV in such cases.

Some stability results for a model of Hepatitis C including alanine aminotransferase and immune system

In clinical practice,many cirrhosis scores based on alanine aminotransferase(ALT)levels exist.Although the most recent direct acting antivirals(DAAs)reduce fibrosis and ALT levels,the Hepatitis C virus(HCV)is not always removed.In this paper,we study a mathematical model of the HCV virus,which takes into account the role of the immune system,to investigate the ALT behavior during therapy.We find five equilibrium points and analyze their stability.A sufficient condition for global asymptotical stability of the infeetion-free equilibrium is obtained and local asymptotical stability conditions are given for the immune-free infection and cytotoxic T lymphocytes(CTL)response equilibria.The stability of the infection equilibrium with the full immune response is numerically performed.

Analysis of the effect of HCV resistance-associated substitutions on the short-term efficacy of DAA after single administration in three phase Ib clinical trials

As crucial factors in hepatitis C virus(HCV)management,resistance-associated substitutions(RASs)are associated with the treatment outcome of some direct-acting antiviral(DAA)-based regimens.In this study,we mainly analyzed the impact of baseline Y93 H or Y93 Y/H on the short-term efficacy after single administration of NS5 A inhibitors in three phaseⅠb clinical trials(yimitasvir phosphate,KW-136 and fopitasvir),and analyzed the prevalence of baseline RASs and treatment-emergent RASs.A total of 94 treatment-naive HCV genotype(GT)-1 b(n=63)and GT-2 a(n=31)Chinese patients were enrolled in three phase lb clinical trials.We investigated RASs in 77 patients with next generation or Sanger sequencing.In the 7-day trial of yimitasvir phosphate,the mean maximum HCV RNA decrease of patients with baseline Y93 H or Y93 Y/H was lower than that of patients without the mutation in the 30 mg and 200 mg cohorts(0.83 vs.2.45 log10 IU/mL and 1.92 vs.2.63 log10 IU/mL).In the3-day trial of KW-136,the mean maximum HCV RNA decrease in patients with baseline Y93 H or Y93 Y/H was lower than that of patients without the mutation in the 30,60 and 120 mg cohorts(1.58 vs.2.89 log10 IU/mL,3.16 vs.4.09 log10 IU/mL and3.00 vs.5.04 log10 IU/mL,respectively).In the 3-day trial of fopitasvir,only 30 mg group had baseline Y93 H or Y93 Y/H,and the average maximum HCV RNA decrease of patients with baseline Y93 H or Y93 Y/H was lower than that of patients without the mutation(1.45 vs.3.59 log10 IU/mL).In the three trials,baseline RASs were observed in 54 patients(70.1%;54/77).The most prevalent baseline RASs were Y93 H and Y93 Y/H(18.2%;14/77),followed by L3 IM(16.9%;13/77).The most common RASs after single administration of DAA were Y93 H and Y93 Y/H.Our data could provide reference for future clinical treatment and clinical trial.