HBV Infection and Host Interactions: The Role in Viral Persistence and Oncogenesis.

Hepatitis B virus (HBV) is a major cause of chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma. Despite the advent of vaccines and potent antiviral agents able to suppress viral replication, recovery from chronic HBV infection is still an extremely difficult goal to achieve. Complex interactions between virus and host are responsible for HBV persistence and the risk of oncogenesis. Through multiple pathways, HBV is able to silence both innate and adaptive immunological responses and become out of control. Furthermore, the integration of the viral genome into that of the host and the production of covalently closed circular DNA (cccDNA) represent reservoirs of viral persistence and account for the difficult eradication of the infection. An adequate knowledge of the virus-host interaction mechanisms responsible for viral persistence and the risk of hepatocarcinogenesis is necessary for the development of functional cures for chronic HBV infection. The purpose of this review is, therefore, to analyze how interactions between HBV and host concur in the mechanisms of infection, persistence, and oncogenesis and what are the implications and the therapeutic perspectives that follow.

Factors affecting long-term changes of liver stiffness in direct-acting anti-hepatitis C virus therapy: A multicentre prospective study.

The long-term changes of liver stiffness (LS) in patients who achieve viral clearance after direct-acting anti-HCV therapy remain undefined. We conducted a multicentre prospective study to investigate this aspect. Patients with HCV infection treated with DAAs were enrolled from six Italian centres; they underwent clinical, biochemical, ultrasound and transient elastography evaluations before treatment (T0), 12 weeks (SVR12) and 24 months (T24) after the end of therapy. Among the 516 consecutive patients enrolled, 301 had cirrhosis. LS significantly decreased from T0 to SVR (14.3 vs 11.1 kPa, p = .002), with a progressive reduction until T24 (8.7 kPa, p < .001). However, only patients with steatosis and those who developed HCC did not experience a late improvement in LS. Multivariate analysis of baseline and follow-up variables identified steatosis as the only independent predictor of failure of LS improvement (OR 1.802, p = .013). ROC curve analysis of the association of LS with the risk of developing HCC showed that SVR12 ≥14.0 kPa had the highest accuracy (sensitivity 82%, specificity 99%; AUC: 0.774). Multivariate analysis revealed that LS was the only variable independently associated with an increased risk of developing HCC (OR 6.470, p = .035). Achieving an SVR was associated with a progressive, long-term decline of LS, suggesting a late improvement in liver fibrosis, besides the resolution of inflammation. Fatty liver and the development of HCC interfered with late reduction of LS. Patients with an LS ≥14 kPa at 12 weeks after the end of treatment were at higher risk for developing HCC.

Factors Enhancing Treatment of Hepatitis C Virus-Infected Italian People Who Use Drugs: The CLEO-GRECAS Experience.

INTRODUCTION: We assessed the performance of direct-acting antivirals (DAAs) in hepatitis C virus (HCV)-infected people who use drugs (PWUDs) in terms of sustained virological response (SVR) and adherence rates in comparison to a location-matched cohort of non-PWUD HCV patients. METHODS: All consecutive HCV RNA-positive PWUDs were enrolled between 2015 and 2019. All subjects underwent DAA treatment according to international guidelines and then followed, at least, up to 12 weeks after the end of treatment (SVR12). The SVR and adherence to treatment was compared with that of non-PWUD HCV patients observed at hepatological units of the CLEO platform. Intention-to-treat analysis was performed. RESULTS: A total of 1,786 PWUDs who were followed up were available for assessment. Most PWUDs (85.4%) were managed inside the specialized outpatient addiction clinics (SerDs). The overall SVR rate was 95.4%. The SerDs group achieved an SVR rate of 96.2% compared with 91.6% of the non-SerDs group (P < 0.001). Comparison with the non-SerDs group and the control HCV group showed a significant difference in the dropout rate (0.6% in the SerDs group versus 2.8% in the non-SerDs group and 1.2% in the control group; P < 0.001). At multivariate analysis, factors independently associated with SVR were use of the most recent regimens (elbasvir/grazoprevir, glecaprevir/pibrentasvir, and sofosbuvir/velpatasvir; odds ratio: 3.126; P = 0.000) and belonging to the SerDs group (odds ratio: 2.356; P = 0.002). DISCUSSION: The performance of DAAs in PWUD is excellent, if 2 conditions are met: (i) that the latest generation drugs are used and (ii) that the patients are managed within the SerDs.

Real-life glecaprevir/pibrentasvir in a large cohort of patients with hepatitis C virus infection: The MISTRAL study.

BACKGROUND AND AIMS: It is paramount to identify predictors of treatment failure with direct antiviral agents in 'field-practice' patients, including people who inject drugs (PWID). Data on the efficacy of glecaprevir/pibrentasvir (GLE/PIB) in a field-practice scenario are scant. The multicentre MISTRAL study enrolled 1177 patients, including PWID, to assess real-life efficacy and safety of GLE/PIB and to identify the predictive factors for this treatment. METHODS: This was a prospective, longitudinal study. The outcome variable was the rate of sustained virological response (SVR) at week 12. RESULTS: A total of 123 patients (10%) were infected from hepatitis C virus (HCV) 3. METAVIR fibrosis score was F4 in 104 subjects (9%); 118 patients (10%) were PWID. Overall, 1163/1177 (99%) patients achieved SVR. The baseline clinical factors discriminating between treatment success and treatment failure were age at treatment (P = 0.031) and creatinine level (P = 0.034). SVR rates were not influenced by gender, substance abuse, previous treatment, treatment duration, fibrosis or chronic kidney disease stage. Compared with non-substance users, the 118 PWID exhibited a significantly different genotype pattern distribution (χ2  < 0.001). A total of 40/118 (33.9%) of substance users were HCV3 compared to 83/1056 (7.9%) non-substance users. Only 6 patients (0.5%) reported a serious adverse event. CONCLUSIONS: The MISTRAL study provides evidence of GLE/PIB efficacy in a field-practice scenario in a highly epidemic HCV area in southern Italy; it unveiled significant differences in genotype distribution among the most underserved and difficult-to-treat patient subgroups including PWID.

Influence of antiviral therapy on the liver stiffness in chronic HBV hepatitis.

PURPOSE: The aim of this study was to evaluate the effects of antiviral therapy on liver stiffness measurement (LSM). METHODS: Two hundred HBV patients were enrolled from four hospital centers in southern Italy; median age was 50.7 (25-75) males were 68%; 171 patients underwent to liver biopsy and 200 patients had LSM at baseline and 189 at the end of follow-up. One hundred and forty-nine patients were treated with nucleos(t)ide analogs, while 51 patients were untreated. The cutoffs of the LSM, related to the fibrosis stages, were as follows: non-advanced fibrosis ≤ 8.1 kPa and advanced fibrosis ≥ 8.2 Kpa. RESULTS: At baseline, the median value of LSM was 14.1 kPa for advanced fibrosis/cirrhosis and 6.9 kPa for non-advanced fibrosis. LSM was performed at 24 months from the start of therapy. The treated patients (68% received Entecavir and 32% Tenofovir) showed a decrease in liver stiffness measurement of 1.5 kPa (p < 0.001) in non-advanced fibrosis and of 6 kPa (p < 0.001) in advanced fibrosis/cirrhosis. In the patients not undergoing antiviral treatment, no statistically significant change of the LSM was observed (p = 0.26). A logistic binary regression model showed that the only independent factor associated with a significant change in the LSM was the liver stiffness value at baseline (odd ratio 2.855; 95% CI 1.456-5.788; (p = 0.007). CONCLUSION: Long-term antiviral therapy induced a significant reduction of liver stiffness measurement and this result may be related to the reduction of liver fibrosis.

"Non alcoholic fatty liver disease and eNOS dysfunction in humans".

BACKGROUND: NAFLD is associated to Insulin Resistance (IR). IR is responsible for Endothelial Dysfunction (ED) through the impairment of eNOS function. Although eNOS derangement has been demonstrated in experimental models, no studies have directly shown that eNOS dysfunction is associated with NAFLD in humans. The aim of this study is to investigate eNOS function in NAFLD patients. METHODS: Fifty-four NAFLD patients were consecutively enrolled. All patients underwent clinical and laboratory evaluation and liver biopsy. Patients were divided into two groups by the presence of NAFL or NASH. We measured vascular reactivity induced by patients' platelets on isolated mice aorta rings. Immunoblot assays for platelet-derived phosphorylated-eNOS (p-eNOS) and immunohistochemistry for hepatic p-eNOS have been performed to evaluate eNOS function in platelets and liver specimens. Flow-mediated-dilation (FMD) was also performed. Data were compared with healthy controls. RESULTS: Twenty-one (38, 8%) patients had NAFL and 33 (61, 7%) NASH. No differences were found between groups and controls except for HOMA and insulin (p < 0.0001). Vascular reactivity demonstrated a reduced function induced from NAFLD platelets as compared with controls (p < 0.001), associated with an impaired p-eNOS in both platelets and liver (p < 0.001). NAFL showed a higher impairment of eNOS phosphorylation in comparison to NASH (p < 0.01). In contrast with what observed in vitro, the vascular response by FMD was worse in NASH as compared with NAFL. CONCLUSIONS: Our data showed, for the first time in humans, that NAFLD patients show a marked eNOS dysfunction, which may contribute to a higher CV risk. eNOS dysfunction observed in platelets and liver tissue didn't match with FMD.

Correction to: "Non alcoholic fatty liver disease and eNOS dysfunction in humans".

After publication of the original article [1], it was noticed that one of the affiliations of author Carmine Vecchione was missing.

HCV antiviral therapy in injection drug users: difficult to treat or easy to cure?

UNLABELLED: Background and rationale of the study. Hepatitis C infection is very common among injection drug users(IDUs). In clinical practice there is reluctance to treat IDUs, because considered difficult-to-treat. Aim of this study was to evaluate the response to antiviral treatment in IDUs compared to non-IDUs. MAIN RESULTS: In this observational retrospective study, 204 non cirrhotic patients(112 IDUs, 92 non-IDUs) with chronic hepatitis C, treated with PEG-IFN and ribavirin in a tertiary centre for IDUs of Southern Italy from 2008 to 2011 were analyzed. Age, sex, genotype, steatosis, response to previous therapy, rapid(RVR), early(EVR), end-of-treatment(ETR), sustained(SVR) virological response were evaluated. IDUs were mainly young and males, with prevalence of genotype 3. A higher SVR rate in IDUs group compared to non-IDUs only in PerProtocol(PP) analysis (90% vs. 78,9% ;p = 0.04). On the contrary, in IntentionToTreat(ITT) analysis, no significant difference was relieved. A higher SVR rate at ITT analyses in naïve non-IDUs patients was found (76,13% vs. 90%, p = 0.021), but at PP analysis wasn't confirmed. Treatment was well tolerated; a higher dropout rate was reported in IDUs (24 patients) compared to non-IDUs (2 patients). In order to exclude the effect of viral genotypes on SVR a genotype matched statistical analysis was done and no difference was found. CONCLUSIONS: IDUs naïve patients, due to young age and high prevalence of genotype 3, appear good candidates to dual antiviral therapy with high SVR rates. Dropout is the main non-response cause among these subjects, but through an optimal monitoring program with a multidisciplinary setting, their "difficult to treat" characteristics can be overcome.

Management of the HBV reactivation in isolated HBcAb positive patients affected with Non Hodgkin Lymphoma.

BACKGROUND: Occult HBV infection (OBI) is defined by the persistence of HBV in the liver without serum HBsAg and HBVDNA. It represents a life-threatening event during immunosuppressive chemotherapies. An OBI occurs in approximately 18% of HBcAb + patients. International guidelines suggest surveillance for HBV markers in immunosuppressed patients. In Non-Hodgkin Lymphoma (NHL), the prevalence of OBI reactivation remains to be established. METHODS: In order to determine the prevalence of occult HBV reactivation in a large cohort of patients during chemotherapy for NHL, we analysed 498 NHL patients in a centre of Southern Italy. We evaluated HBV markers, NHL type, treatment type and occurrence of HBV reactivation. RESULTS: Forty % of patients were treated with monoclonal antibodies and 60.3% without. Ninety-six patients were HBcAb+, HBsAg-. HBV reactivation occurred in ten subjects of this subgroup. All of them were successfully treated with Lamivudine. None of the patients experienced liver-related death. The prevalence of OBI reactivation was of 10.42% in HBcAb + HBsAb- patients. This event occurred in 50% of patients treated with mild immunosuppressive therapies. Each reactivation was treated with Lamivudine. DISCUSSION: This report suggests that a strict surveillance is important and cost-effective in HBcAb + HBsAg- NHL patients treated with mild immunosuppressive therapies, in order to detect an occult HBV reactivation.

A holistic evaluation of patients with chronic Hepatitis D virus (HDV) infection enrolled in the Italian PITER-B and delta cohort.

BACKGROUND AND AIMS: We aimed to characterize the epidemiologic and comorbidities profiles of patients with chronic Hepatitis D (CHD) followed in clinical practice in Italy and explored their interferon (IFN) eligibility. METHODS: This was a cross-sectional study of the PITER cohort consisting of consecutive HBsAg-positive patients from 59 centers over the period 2019-2023. Multivariable analysis was performed by logistic regression model. RESULTS: Of 5492 HBsAg-positive enrolled patients, 4152 (75.6%) were screened for HDV, 422 (10.2%) were anti-HDV positive. Compared with HBsAg mono-infected, anti-HDV positive patients were more often younger, non-Italians, with a history of drug use, had elevated alanine transaminase (ALT), cirrhosis, or hepatocellular carcinoma (HCC). Compared with Italians, anti-HDV positive non-Italians were younger (42.2% age ≤ 40 years vs. 2.1%; P < 0.001), more often females (males 43.0% vs. 68.6%; P < 0.001) with less frequent cirrhosis and HCC. HDV-RNA was detected in 63.2% of anti-HDV-positive patients, who were more likely to have elevated ALT, cirrhosis, and HCC. Extrahepatic comorbidities were present in 47.4% of anti-HDV positive patients and could affect the eligibility of IFN-containing therapies in at least 53.0% of patients in care. CONCLUSIONS: CHD affects young, foreign-born patients and older Italians, of whom two-thirds had cirrhosis or HCC. Comorbidities were frequent in both Italians and non-Italians and impacted eligibility for IFN.

Gender Differences in the Pathogenesis and Risk Factors of Hepatocellular Carcinoma.

Several chronic liver diseases are characterized by a clear gender disparity. Among them, hepatocellular carcinoma (HCC) shows significantly higher incidence rates in men than in women. The different epidemiological distribution of risk factors for liver disease and HCC only partially accounts for these gender differences. In fact, the liver is an organ with recognized sexual dysmorphism and is extremely sensitive to the action of androgens and estrogens. Sex hormones act by modulating the risk of developing HCC and influencing its aggressiveness, response to treatments, and prognosis. Furthermore, androgens and estrogens are able to modulate the action of other factors and cofactors of liver damage (e.g., chronic HBV infection, obesity), significantly influencing their carcinogenic power. The purpose of this review is to examine the factors related to the different gender distribution in the incidence of HCC as well as the pathophysiological mechanisms involved, with particular reference to the central role played by sex hormones.

Neoadjuvant and Adjuvant Systemic Therapies in Loco-Regional Treatments for Hepatocellular Carcinoma: Are We at the Dawn of a New Era?

Despite maximizing techniques and patient selection, liver resection and ablation for HCC are still associated with high rates of recurrence. To date, HCC is the only cancer with no proven adjuvant or neoadjuvant therapy used in association to potentially curative treatment. Perioperative combination treatments are urgently needed to reduce recurrence rates and improve overall survival. Immunotherapy has demonstrated encouraging results in the setting of adjuvant and neoadjuvant treatments for non-hepatic malignancies. Conclusive data are not yet available in the context of liver neoplasms. However, growing evidence suggests that immunotherapy, and in particular immune checkpoint inhibitors, could represent the cornerstone of an epochal change in the treatment of HCC, improving recurrence rates and overall survival through combination treatments. Furthermore, the identification of predictive biomarkers of treatment response could drive the management of HCC into the era of a precision medicine. The purpose of this review is to analyze the state of the art in the setting of adjuvant and neoadjuvant therapies for HCC in association with loco-regional treatments in patients not eligible for liver transplantation and to hypothesize future scenarios.

Elimination of Hepatitis C in Southern Italy: A Model of HCV Screening and Linkage to Care among Hospitalized Patients at Different Hospital Divisions.

Background: Free-of-charge HCV screening in some key populations and in 1969-1989 birth cohorts has been funded in Italy as the first step to diagnosing individuals who are infected but asymptomatic. The aim of this study is to evaluate the feasibility of an opportunistic HCV screening and its linkage to care. Methods: A hospital-based HCV screening was conducted as a routine test for in-patients admitted to the Evangelical Hospital Betania of Naples from January 2020 to May 2021. All consecutive in-patients were screened for the HCV antibody (HCV-Ab) at the time of their admission to the hospital, and those born prior to year 2000 were included in the study. HCV-RNA testing was required for those not previously treated and without antiviral treatment contraindications. For in-patients with an active infection, treatment started soon after hospital admission. Results: Among 12,665 inpatients consecutively screened, 510 (4%) were HCV-Ab positive. The HCV-Ab positivity rate increased with age, reaching the highest prevalence (9.49%) in those born before 1947. Among patients positive for HCV, 118 (23.1%) had been previously treated, 172 (33.9%) had been discharged before being tested for HCV-RNA, and 26 (5.1%) had not been tested for short life expectancy. Of 194 (38% of HCV-Ab+) patients who were tested for HCV-RNA, 91 (46.2%) were HCV-RNA positive. Of patients with active infection, 33 (36%) were admitted to the liver unit with signs of liver damage either not previously diagnosed or diagnosed but unlinked to care for HCV infection. Of the patients positive for HCV-RNA, 87 (95.6%) started treatment; all achieved sustained virological response. Conclusion: HCV active infection has been frequently found in patients with comorbidities admitted in the hospital in Southern Italy. To achieve HCV elimination in Italy, broader screening strategies are required. In addition to screening of the 1969-1989 birth cohort of individuals unaware of their infection status, diagnosis and linkage to care of patients with known liver damage is strictly required. Hospital screening is feasible, but prompt reflex testing for identifying HCV-active infections is necessary to increase diagnosis and subsequent linkage to care.

Telemedicine Improves HCV Elimination among Italian People Who Use Drugs: An Innovative Therapeutic Model to Increase the Adherence to Treatment into Addiction Care Centers Evaluated before and during the COVID-19 Pandemic.

People who use drugs (PWUDs) are generally considered "hard-to-treat" patients, due to adherence to HCV antiviral therapy or re-infection concerns. Linkage-to-care still remains a significant gap for HCV elimination, worsened by the COVID-19 pandemic. To reduce time-to-treat and improve treatment adherence, we have developed a patient-tailored model-of-care, decentralized within the addiction center and supervised remotely by hepatologists. From January 2017 to December 2020, patients were enrolled in one addiction care center in Southern Italy, where a complete hepatologic assessment, including blood chemistry, ultrasound, and transient elastography examination, was provided. DAAs treatment has been adapted on clinical features, also performing a daily administration during an outpatient visit, and monitored remotely by specialists via telemedicine interactions. Adherence was evaluated on the accomplishment of therapy or on the percentage of attended visits. From a total of 690 PWUDs, 135 had an active HCV infection and were enrolled in the study. All patients started the treatment within 3 weeks after HCV diagnosis. Six drop-outs were recorded, obtaining a sustained virological response at week 12 (SVR12) in 98.5% of PWUDs. There were only two cases of treatment failure, one of which is re-infection. No differences were found between the SVR12 rates before and during the COVID-19 pandemic. We obtained a high SVR12 rate, providing a comprehensive assessment within the addiction care center, tailoring the drug administration with a hepatologic remote stewardship. Our therapeutic model should improve the time-to-treat and treatment adherence in PWUDs.

Epidemiology of HCV and HBV in a High Endemic Area of Southern Italy: Opportunities from the COVID-19 Pandemic-Standardized National Screening or One Tailored to Local Epidemiology?

The COVID-19 pandemic led to the hospitalization of an unselected population with the possibility to evaluate the epidemiology of viral hepatitis. Thus, a retrospective multicenter study was conducted in an area of Southern Italy with the aim of assessing the prevalence of HCV and HBV markers and the ability of current screening program to capture cases. We evaluated 2126 hospitalized patients in seven COVID Centers of Naples and Caserta area in which 70% of the Campania population lives. HBsAg and HCV-Ab prevalence was 1.6% and 5.1%, respectively, with no differences between gender. Decade distribution for birth year shows a bimodal trend of HCV prevalence, with a peak (11.6%) in the decade 1930-1939 and a second peak (5.6%) for those born in 1960-1969. An analysis of the screening period imposed by the Italian government for those born between 1969 and 1989 shows that only 17% of cases of HCV infection could be captured. A small alignment of the screening period, i.e., those born from 1960 to 1984, would capture 40% of cases. The data confirm the high endemicity of our geographical area for hepatitis virus infections and underline the need for a tailored screening program according to the regional epidemiology.

Can Telemedicine Optimize the HCV Care Cascade in People Who Use Drugs? Features of an Innovative Decentralization Model and Comparison with Other Micro-Elimination Strategies.

People who use drugs (PWUDs) are a crucial population in the global fight against viral hepatitis. The difficulties in linkage to care, the low adherence to therapy, the frequent loss to follow-up and the high risk of re-infection make the eradication process of the hepatitis C virus (HCV) really hard in this viral reservoir. Several management and treatment models have been tested with the aim of optimizing the HCV care cascade in PWUDs. Models of decentralization of the care process and integration of services seem to provide the highest success rates. Giving this, telemedicine could favor the decentralization of diagnostic-therapeutic management, key for the implementation of linkage to care, reduction of waiting times, optimization of adherence and results and reduction of the costs. The purpose of this literature review is to examine the role and possible impact of telemedicine in optimizing the HCV care cascade, comparing the different care models that have shown to improve the linkage to care and therapeutic adherence in this special population.

The Role of Fructose in Non-Alcoholic Steatohepatitis: Old Relationship and New Insights.

Non-alcoholic fatty liver disease (NAFLD) represents the result of hepatic fat overload not due to alcohol consumption and potentially evolving to advanced fibrosis, cirrhosis, and hepatocellular carcinoma. Fructose is a naturally occurring simple sugar widely used in food industry linked to glucose to form sucrose, largely contained in hypercaloric food and beverages. An increasing amount of evidence in scientific literature highlighted a detrimental effect of dietary fructose consumption on metabolic disorders such as insulin resistance, obesity, hepatic steatosis, and NAFLD-related fibrosis as well. An excessive fructose consumption has been associated with NAFLD development and progression to more clinically severe phenotypes by exerting various toxic effects, including increased fatty acid production, oxidative stress, and worsening insulin resistance. Furthermore, some studies in this context demonstrated even a crucial role in liver cancer progression. Despite this compelling evidence, the molecular mechanisms by which fructose elicits those effects on liver metabolism remain unclear. Emerging data suggest that dietary fructose may directly alter the expression of genes involved in lipid metabolism, including those that increase hepatic fat accumulation or reduce hepatic fat removal. This review aimed to summarize the current understanding of fructose metabolism on NAFLD pathogenesis and progression.

Corrigendum to "Role of Oxidative Stress in Pathophysiology of Nonalcoholic Fatty Liver Disease".

[This corrects the article DOI: 10.1155/2018/9547613.].

Unusual liver-related heart injury.

A 72-year-old man with polycystic liver disease and unexplained shock was admitted to our Emergency Department. The presence of turgidity in the jugular veins and acute prerenal kidney failure led to a possible hypothesis of right ventricular heart failure. A massive hepatic cyst resulted in right atrial compression and, secondarily, a state of shock. Surgical decompression by drainage of the hepatic cyst resulted in rapid improvement in the patient's hemodynamics. We report the description of an extremely rare complication of polycystic liver disease.

Directly Acting Antiviral-Based Treatment for HCV-Infected Persons Who Inject Drugs: A Multicenter Real-Life Study.

BACKGROUND: We aimed to evaluate the factors associated with a virological response in a cohort of Hepatitis C virus (HCV)-infected people who inject drugs (PWID) treated with direct acting antivirals (DAAs). METHODS: We conducted a multicenter retrospective cohort study enrolling HCV-infected PWID treated with DAAs. The primary outcome evaluated was the sustained virological response (SVR12) rate. RESULTS: Five hundred and twenty HCV-infected PWID treated with all-oral DAA-based regimens were enrolled; a total of 168 (32.3%) patients presented genotype 1a, 109 (21.0%) genotype 1b, and 174 (33.5%) genotype 3; a total 152 of the 520 subjects (29.2%) were cirrhotics; a total 118 (22.7%) and 373 (71.7%) were treated with DAA regimens of second and third generation, respectively; a total 169 (33.6%) patients were receiving an opioid agonist at the start of antiviral therapy. Only 11 subjects (2.1%) did not show an SVR12. A significant correlation was found between treatment with opioid substitution therapy (p < 0.001), Human Immunodeficiency Virus (HIV) coinfection (p = 0.002), and treatment with first- or second-generation regimens (p = 0.0015) and HCV failure. Upon multivariate analysis, treatment with a first- or second-generation DAA was the only factor independently associated with failure (OR 10.4, 95% CI: 1.43 to 76.1, p = 0.02). CONCLUSIONS: Treatment with DAAs led to a high SVR12 rate (97.9%) in a large cohort of HCV-infected PWID. The only predictor of viral failure found in our analysis was treatment with first- and second-generation DAA.