Use of RNA interference to modulate liver adenoma development in a murine model transgenic for hepatitis B virus.

Chronic hepatitis B virus (HBV) infection is closely related to the development of severe liver complications, including hepatocellular carcinoma. In previous studies, we reported that in vivo long-term HBV suppression in transgenic mice can be achieved without apparent toxicity by short hairpin RNA sequentially delivered using adeno-associated viral (AAV) vectors of different serotypes. Our goal herein was to address the clinical utility of this delivery system and, in particular, to determine whether RNA interference (RNAi) and its ability to induce long-term HBV suppression will modulate the development of HBV-associated liver pathology. As a model system, we used a unique HBV transgenic mouse model, containing a 1.3 times over length of the HBV genome, on the ICR mouse background. These transgenic mice produce high serum HBV titers comparable with human chronic HBV patients, and, importantly, manifest characteristic HBV-associated pathology, including progressive hepatocellular injury and the development of hepatocellular adenoma. Using this system, we injected animals with AAV vectors expressing either HBV-specific or a control luciferase-specific short hairpin RNA and followed animals for a total of 18 months. We report herein that AAV-mediated RNAi therapy profoundly inhibits HBV replication and gene expression, with a significant reduction in hepatic regeneration, liver enzymes and, importantly, the appearance of liver adenomas. Indeed, the therapeutic effect of RNAi correlated with the reduction in HBV titers. Our data demonstrate that appropriately designed RNAi therapy has the potential to prevent formation of HBV-associated hepatocellular adenoma.

Transplantation After Successful Downstaging by Multimodal Treatments of American Joint Committee on Cancer Stage IIIB Hepatocellular Carcinoma With Portal Vein Thrombi: A Case Report.

The effective treatment for hepatocellular carcinoma (HCC) with American Joint Committee on Cancer stage IIIB remains controversial and challenging because of the high recurrence rate after resection and low survival rate. The median survival of those with macroscopic portal vein tumor thrombus (PVTT) is short. We reported such a case which received liver transplantation (LT) after successful consecutive downstaging therapies. A 40-year-old man with alcohol related liver cirrhosis and repeated esophageal varices bleeding had HCC with tumor thrombi in right main portal vein and the second portal branch of segment VI (stage IIIB). The received percutaneous alcohol injection, radiofrequency ablation, 8 sessions of transcatheter hepatic arterial chemoembolization, radiotherapy, and target therapy with sorafenib. Computed tomography (CT) scan and magnetic resonance imaging after treatments showed no viable fragments in the tumor and revealed both the right main portal vein and V1 branch were patent. One month later, the patient received a deceased LT. The perioperative course was rather smooth. After discharge, the interval follow-up CT studies of the chest and liver and whole body bone scan showed no tumor recurrence or metastasis up to 20 months postoperation.

Early Detection of a Hepatic Artery Pseudoaneurysm After Liver Transplantation Is the Determinant of Survival.

BACKGROUND: Hepatic artery pseudoaneurysm (PA) after liver transplantation (LT) is a rare but potentially fatal complication. Among a series of 50 patients of LT, we experienced 3 such cases. Some authors also have reported cases of PA, either intrahepatic or extrahepatic. The aim of this study was to investigate the important factors that affect the treatment outcome. METHODS: Three patients were presented. To analyze the factors, not only our patients but also the patients with PA reported in the literature (including 10 case series and 23 case reports) were enrolled for analysis. The possible factors probably affecting the survival were compared statistically, including age, sex, clinical manifestation as bleeding (including gastrointestinal bleeding, hemobilia, or intra-abdominal bleeding), treatment (with embolization or surgical exploration or stent), diagnosis establishment before or after bleeding, and so forth. RESULTS: From univariate analysis, the significant factors that affect survival are sex (female) (P = .036), stent treatment (P = .006), and early detection (P = .036), whereas age (P = .493) and presentation with hemorrhage (P = .877) are not significant factors. However, according to multivariate analysis, stent treatment has a borderline significance (P = .056). CONCLUSIONS: Early detection of such a life-threatening complication is a key determinant of survival. "Early" does not refer to early postoperative days but means the detection prior to the rupture of the pseudoaneurysm. Postoperative imaging studies such as computed tomographic scan or magnetic resonance cholangiopancreatography early and periodically to follow up the graft status is recommended, especially for those who had received other interventions before or after the liver transplantation.

Early incarcerated diaphragmatic hernia following right donor hepatectomy: a case report.

Right diaphragmatic hernia after donor hepatectomy is extremely rare. The occurrence is usually late. We present a case with early occurrence complicated with small bowel strangulation. Early detection and emergency surgical repair relieved the problem quickly. Predisposing factors are discussed. To avoid such a complication is very important.

Delayed formation of gallstone after transcatheter arterial embolization for hepatocellular carcinoma. Is elective cholecystectomy advisable during hepatectomy?

Two hundred twenty-five transcatheter hepatic arterial embolizations (TAEs) were performed on 137 patients with hepatocellular carcinoma (HCC) during a three-year period. The postembolization changes of the gallbladder were studied by regular follow-up with ultrasonography. Twenty-four patients (10.7%) were found to have an acute infarction of the gallbladder within two weeks immediately following chemoembolization. Gallbladder infarction was related to inadequate superselectivity, regurgitation of chemoembolus, or unavoidable anatomic limitations. Four of the 24 patients were found to have delayed formation of gallstones, with the time lapses after TAEs being 2, 2, 3, and 5 months, respectively. One patient underwent surgical reexploration for cholecystectomy 14 months after resection of her HCC because of intractable symptoms and signs of chronic cholecystitis. There are four possible mechanisms of development of gallstones. Cholecystectomy should be performed during the elective hepatectomy for resectable HCC in patients who have received preoperative TAEs.

Reappraisal of the systematic management of complicated hepatolithiasis with bilateral intrahepatic biliary strictures.

OBJECTIVE: To compare the results, limitations, and complications of the surgical treatment of bilateral hepatolithiasis and intrahepatic biliary strictures with left hepatectomy and without left hepatectomy. DESIGN: Case-controlled study. SETTING: Referral center. PATIENTS: During a 12-year period, 103 patients with bilateral hepatolithiasis and intrahepatic biliary strictures underwent surgical treatment. Group A (n = 73) received left hepatic resection (lateral segmentectomy or lobectomy) and postoperative biliary dilatation with residual stone extraction. Group B (n = 30) underwent the same procedures except for left hepatectomy. INTERVENTIONS: Left lateral segmentectomy or left lobectomy, choledocholithotomy, postoperative cholangioscopic treatments (electrohydraulic lithotripsy, other lithotripsy, lithotomy, balloon dilatation, etc. via T tube or precutaneous transhepatic route). MAIN OUTCOME MEASURES: Days of hospitalization, incidence of major and minor complications, mortality rates, and the rates of residual stones and stone recurrence were compared. RESULTS: Group A and B had similarly low postoperative 1-month mortality rates of 5.5% and 6.7%, respectively. The main cause of death in both groups was uncontrollable septicemia. The main major complications in group A were intra-abdominal abscess and upper gastrointestinal bleeding; the major complication in group B was massive hemobilia. Group B had a significantly higher overall rate of complications (53.3% vs 23.3%, P < .01) and a longer hospital stay than group A (median, 72 days vs 28 days, P < .03). When complications were classified as major or minor, only minor complications showed a significant difference (30% vs 13.7%, P = .05). After using biliary stricture dilatation and stone extraction, the rate of residual stones in the right lobe was similar in both groups, but patients in group B had a significantly higher rate of residual stones (12.5% vs 0%, P < .02) and stone recurrence in the left lobe (19% vs 0%, P < .003) than those in group A. CONCLUSIONS: Partial resection of the left lobe in cases of bilateral hepatolithiasis and biliary strictures can effectively simplify problems in the treatment of bilateral hepatolithiasis and intrahepatic biliary strictures. In addition, not only were surgical complications not increased, but a decrease in complications from postoperative manipulations for stone clearance was noted in our series.

Are expandable metallic stents better than conventional methods for treating difficult intrahepatic biliary strictures with recurrent hepatolithiasis?

BACKGROUND: Conventional methods for treating patients with recurrent hepatolithiasis associated with complicated intrahepatic biliary strictures include balloon dilatation of the intrahepatic biliary strictures, lithotripsy, and the clearance of difficult stones as completely as possible, with the placement of an external-internal stent for at least 6 months. After these modalities are used, symptomatic refractory strictures remain. Recently we used internal Gianturco-Rosch metallic Z stents to treat patients who had refractory strictures. OBJECTIVE: To compare therapeutic results and complications of an internal expandable metallic Z stent with those of repeated external-internal stent placement. STUDY DESIGN: Case-control study. SETTING: A referral center. PATIENTS: From January 1992 to December 1996, 18 patients with recurrent hepatolithiasis and complicated intrahepatic biliary strictures underwent percutaneous dilatation of stricture and transhepatic percutaneous cholangioscopic lithotomy for recurrent stones. After their stones were completely cleared, their biliary strictures failed to dilate satisfactorily. The patients were randomly enrolled into 2 groups: group A (7 patients), who received an expandable metallic Z stent, and group B (11 patients), who had repeated placement of external-internal stents. INTERVENTIONS: Percutaneous stricture dilatation, electrohydraulic lithotripsy, balloon dilatation, percutaneous transhepatic cholangioscopic lithotomy, and biliary stenting by a Silastic external-internal catheter or a modified Gianturco-Rosch expandable metallic Z stent (for an internal stent). MAIN OUTCOME MEASURES: The number of procedures, days in hospital, procedure-related complications, incidents of stone recurrence and recurrence of cholangitis, readmissions to the hospital, treatment sessions required, and mortality rate. Patients' limitations in ordinary activities were also compared. RESULTS: The follow-up period ranged from 28 to 60 (40.7+/-12.7 [mean +/- SD]) months in group A and from 28 to 49 (36.0+/-7.2) months in group B. Fewer group A patients (3 [43%]) than group B patients (8 [73%]) tended to have recurrent cholangitis and to require readmission to the hospital, but this was not statistically significant (P = .33). When their cumulative probability of a first episode of cholangitis during follow-up was compared, however, it was significantly lower in patients treated with a metallic stent (P = .04). Compared with group B patients, group A patients had less frequent recurrence of stones (0% vs 64%; P = .01), fewer procedures for the clearance of biliary stones or sludge (1.7+/-2.2 vs 6.4+/-4.3; P = .03), and shorter hospital stays (8.0+/-11.5 days vs 17.0+/-12.0 days; P = .07). No patients in group A experienced limitation in ordinary activities, whereas 7 patients in group B did (P<.02). CONCLUSIONS: Compared with the repeated placement of external-internal stents, the use of a metallic internal stent effectively decreases stone recurrence, simplifies further procedures, and is more convenient. Its use is suggested as an alternative choice in the treatment of recurrent hepatolithiasis with refractory intrahepatic biliary strictures.

Is the p53 gene mutation of prognostic value in hepatocellular carcinoma after resection?

HYPOTHESIS: Mutant p53 gene has lost its tumor suppression function and is considered to be a very important step in hepatocellular carcinoma development. We propose that the mutant p53 gene plays a role in its invasiveness and prognosis after resection. DESIGN: A case-controlled study. SETTING: A referral center. PATIENTS: Seventy-nine consecutive patients who underwent surgical resection for hepatocellular carcinoma entered this study. INTERVENTION: Tissue sections of resected hepatocellular carcinoma (deparaffinized and rehydrated from formalin-fixed and paraffin-embedded sections) were incubated with antihuman p53 monoclonal antibody and immunostained. The p53 result was scored without prior knowledge of the patients' status. A 10% immunopositivity was regarded as the threshold value. MAIN OUTCOME MEASURE: The immunopositive rate of p53 was 69.6% (55 of 79 patients). The clinical variables (age, sex, associated liver cirrhosis, hepatitis B virus infection, hepatitis C virus infection, serum alpha-fetoprotein, and Child-Pugh class); the histological variables (size, capsule, vascular permeation; grade of differentiation, and multinodularity); and postoperative course (recurrence, tumor-free interval, death, and survival period) were correlated with p53 immunopositivity. RESULTS: From univariate analysis, more patients with p53 positivity were male (92.7 vs 0%) (P<.001); had vascular permeation (80% vs 50%) (P =.007) (odds ratio [OR], 4.0); no complete capsule (83.6% vs 62.5%) (P =.04) (OR, 3.1); and daughter nodules (90.9% vs 70.8%) (P =.04) (OR, 4.1) than patients with negative p53 staining. From multivariate analysis, only sex and vascular permeation remained significant (P =.001 and P =.008, respectively). Although more patients with p53 positivity had tumor recurrence (78% vs 50%) (P =.01) and death (64% vs 33%) (P =. 01), the Cox proportional hazards model showed that p53 overexpression had only weak correlations with tumor-free interval and survival time (P =.09 and P =.08, respectively). CONCLUSIONS: Our results show that the biological behavior of the mutant p53 gene is strongly related to the invasiveness of hepatocellular carcinoma and may also influence the postoperative course. We suggest that the immunopositivity of the mutant p53 gene has a predictive role in the prognosis of patients with resected hepatocellular carcinoma.

Secondary biliary cirrhosis. A limiting factor in the treatment of hepatolithiasis.

To investigate whether the coexistence of secondary biliary cirrhosis plays a limiting role in the treatment of hepatolithiasis, we retrospectively compared the clinical course and results of stone treatment in 30 patients with secondary biliary cirrhosis (8 in Child's class A and 22 in Child's class B) (group 1) and 240 patients with noncirrhotic biliary calculi (group 2). The hospital mortality, morbidity of treatment, mortality of treatment, and the percentage of treatment failure in group 1 were 20%, 40%, 6.7%, and 16.7%, respectively. Those in group 2 were 8%, 10%, 3.8%, and 10%, respectively. The modes of treatment for stone removal included surgery with postoperative cholangioscopy and percutaneous transhepatic cholangioscopy. There was a statistically significant difference between these two groups in the hospital mortality and the morbidity of treatment. We conclude that hepatolithiasis and biliary stricture should be treated early, before the development of secondary biliary cirrhosis. However, even after cirrhosis occurs, aggressive treatment does not increase the mortality of treatment or the treatment failure rate.

Coexisting sharp ductal angulation with intrahepatic biliary strictures in right hepatolithiasis.

OBJECTIVE: To investigate the clinical characteristics of a coexisting sharp ductal angulation (< 90 degrees) with biliary stricture and to evaluate the difficulties it imposes in the management of retained or recurrent hepatolithiasis. DESIGN: Case-controlled study. SETTING: A referral center. PATIENTS: Eighteen consecutive patients having right-sided hepatolithiasis and a coexisting sharp ductal angulation associated with biliary stricture (group 1) were compared with 84 patients matched with sex, age, and conditions of hepatolithiasis and intrahepatic biliary stricture(s) but no sharp angulated duct (group 2). INTERVENTION: Postoperative cholangioscopic management (electrohydraulic lithotripsy or other lithotripsy, lithotomy, balloon dilation, biopsy, etc, via T-tube tract or percutaneous transhepatic route). MAIN OUTCOME MEASURES: Sessions of manipulations, incidence of complications associated with interventions or disease, and mortality were compared. RESULTS: Patients of group 1 needed more sessions of postoperative manipulation of stones and strictures (13.7 +/- 4.2 vs 8.0 +/- 2.3; P < .001). During management, there was a significantly increased vulnerability of severe and/or recurrent cholangitis (66.7% vs 9.5%; P < .001), septic shock (77.8% vs 11.9%; P < .001), liver abscess (55.6% vs 7.1%; P < .001), or massive hemobilia (33.3% vs 7.4%) in group 1 than in group 2. Their risks of coexisting secondary biliary cirrhosis (55.6% vs 9.5%; P < .001) and/or cholangiocarcinoma (16.6% vs 2.4%; P < .04) and mortality (27.8% vs 4.8%; P < .01) were also significantly higher in group 1. CONCLUSION: Our results suggest that the coexisting sharp ductal angulation with biliary strictures in right-sided hepatolithiasis is a distinct difficult clinical entity in the field of biliary tract calculi.

Treatment of intrahepatic biliary stricture associated with hepatolithiasis.

Biliary stricture is a difficult complication in the management of hepatolithiasis. Resection of the hepatic segment containing biliary stricture(s) is ideal. Dilatation and stenting therapy with PTCSL in selective cases is a good adjuvant, sometimes alternative, therapy. We recommend a combination of multimodal treatment with a systemic approach to improve results. For recurrent or residual cases, PTCSL becomes the mainstay of treatment.

Percutaneous transhepatic cholangioscopy in the treatment of complicated intrahepatic biliary strictures and hepatolithiasis with internal metallic stent.

For recurrent hepatolithiasis coexisting with a complicated long-segment intrahepatic biliary stricture, repeated surgeries, balloon dilation of the stricture, and external-internal stenting may still fail to solve the problem. We tried using a Gianturco-Rosch metallic Z internal stent (Wilson-Cook Medical, Inc., Bloomington, IN, USA) with the aid of percutaneous transhepatic cholangioscopy (PTCS) to treat such patients. Eight patients had a Z stent placed through a percutaneous transhepatic biliary drainage tract. Immediately after stent placement, PTCS was inserted via the percutaneous transhepatic biliary drainage route and a part of the wire skirt not firmly anchored in one of the eight patients was detected. It was successfully repositioned using PTCS. Recurrent cholangitis developed in three patients 6, 7, and 30 months, respectively, after stent placement. PTCS was undertaken again through a reestablished percutaneous transhepatic biliary drainage route and revealed sludge in their stent lumens. We cleared it by PTCS. No further cases of cholangitis occurred in later follow-up. PTCS is useful in ensuring adequate stent position, diagnosing and treating the causes of recurrent cholangitis, and prolonging the function of stents.

The benefits of a second transhepatic route in failed percutaneous management of difficult intrahepatic biliary strictures with recurrent hepatolithiasis.

Percutaneous stricture dilatation and cholangioscopic lithotomy has become a mainstay in the treatment of patients with recurrent hepatolithiasis associated with intrahepatic biliary strictures. In a consecutive series of 125 patients who underwent percutaneous management of recurrent hepatolithiasis from 1987 to 1999, there were 15 patients in whom the procedure failed to clear the stones. A second percutaneous transhepatic route was established for subsequent treatment. A reappraisal of its indications and efficacy was done. Treatment through a second route was helpful for patients with bilateral strictures, angulated duct, difficult strictures, large impacted stones, a subcutaneous jejunal limb, or hemobilia developing in the first route. Strictures remained impacted in 1 of the 15 patients (failure rate, 7%), with the remaining having complete clearance of stones. Cholangitis occurred in two patients; no other complications were encountered. A second percutaneous route is very helpful for the management of complicated hepatolithiasis and biliary stricture.

Intrahepatic segmental portal vein thrombosis after living-related donor liver transplantation.

BACKGROUND: Intrahepatic segmental portal vein thrombosis after living-related liver transplantation (LRLT) is uncommon. The cause remains unclear. METHODS: After providing written informed consent, 25 recipients receiving LRLT at our institution from January 2011 to September 2013 were enrolled in this study. We performed triphase computerized tomographic (CT) study of the liver graft of each recipient 1 month after LRLT. The patencies of hepatic artery, portal vein, and hepatic vein were evaluated in detail. The triphase CT scans of the liver of each donor before transplantation also were reviewed. Thrombosis of the intrahepatic segmental portal vein was defined as the occlusion site of the portal vein being intrahepatic. Extrahepatic portal vein thrombosis was excluded in this study. RESULTS: Among the 25 patients, 2 (8%) developed thrombosis of intrahepatic segmental portal vein. One 47-year-old man received LRLT for hepatitis B viral infection-related liver cirrhosis (Child-Pugh class C) with 3 hepatocellular carcinomas (total tumor volume <8 cm). Another 53-year-old man received LRLT for alcoholic liver cirrhosis (Child-Pugh class C). Both had developed progressive jaundice and cholangitis 1 month after surgery. Intrahepatic biliary stricture was found on the follow-up magnetic resonance images. However, liver triphase CT study demonstrated occlusion of intrahepatic portal vein of segment 8 in each patient. Radiologic interventions and balloon dilatation therapy via percutaneous transhepatic biliary drainage route improved the symptoms and signs of cholangitis and obstructive jaundice for both. CONCLUSIONS: Thrombosis of intrahepatic segmental portal vein is not common but is usually associated with complications of intrahepatic bile duct. Early detection is important, and follow-up CT study of liver is suggested.

Repeated introperative cholangiography is helpful for donor safety in the procurement of right liver graft with supraportal right bile duct variants in living-donor liver transplantation.

BACKGROUND: Despite recent advances in preoperative diagnostic imaging and operative techniques, biliary variation of the donor still remains a challenge in the procurement of graft. The supraportal right bile duct (BD) variant including presentation as trifurcation is a potential trap for injuring the remnant bile duct of donor. METHODS: Before living/related-donor liver transplantation (LRLT), cholangiogram with magnetic resonance images of each donor was performed as a routine. After exploration of the donor before hilar dissection, intraoperative chloangiography (IOC) was routinely performed. Among the supraportal right bile duct variants, if the preoperative cholangiography showed a suspected trifurcation of the bile duct, we then performed 3 sessions of IOC during liver graft procurement, including prior to hilar dissection, before the division of bile ducts and after the division. We reviewed the cholangiogram and the postoperative laboratory data of a consecutive series of 25 donors of LRLT. RESULTS: There was no division injury of the remnant bile duct of all of the donors. CONCLUSIONS: Repeated IOC is suggested as a routine for variants of supraportal right bile ducts especially trifurcation pattern in graft procurement to avoid the injury of donor remnant bile ducts.

Loss of speech after living-related donor liver transplantation: detection of the lesion by diffusion tensor image.

INTRODUCTION: Loss of speech after living-related liver transplantation is uncommon. Either immunosuppressive agents, related sequelae, or a neurological event may cause it. CASE REPORT: A 46-year-old man developed dysarthria and dysphagia on the 10th day after living-related donor liver transplantation for alcoholic cirrhosis with Child-Pugh class C. Brain magnetic resonance images and electroencephalograms could not detect any lesion, but the diffusion tensor image showed a subacute lacunar infarction at right midbrain. The patient's speech improved 1 month after rehabilitation. CONCLUSIONS: Some unexpected neurological events, such as loss of speech, may occur after liver transplantation. The differential diagnosis becomes very important before active treatment. Magnetic resonance imaging supplemented with diffusion tensor imaging is an effective imaging study in establishing the diagnosis.

Case report: maximum-intensity projection and minimum-intensity projection of computed tomography are helpful in the diagnosis of Budd-Chiari syndrome in complicated liver cirrhosis.

BACKGROUND: Early detection of Budd-Chiari syndrome (BCS) to give the appropriate therapy in time is crucial. Angiography remains the golden standard to diagnose BCS. However, to establish the diagnosis of BCS in complicated cirrhotic patients remains a challenge. We used maximum intensity projection (Max IP) and minimum intensity projection (Min IP) from computed tomographic (CT) images to detect this syndrome in such a patient. CASE REPORT: A 55-year-old man with a history of chronic hepatitis B infection and alcoholism had undergone previously a left lateral segmentectomy for hepatic epitheloid angiomyolipoma (4.6 × 3.5 × 3.3 cm) with a concomitant splenectomy. Liver decompensation with intractable ascites and jaundice occurred 4 months later. The reformed images of the venous phase of enhanced CT images with Max IP and Min IP showed middle hepatic vein thrombosis. He then underwent a living-related donor liver transplantation with a right liver graft from his daughter. Intraoperatively, we noted thrombosis of his middle hepatic vein protruding into inferior vena cava. The postoperative course was unevenful. Microscopic findings revealed micronodular cirrhosis with mixed inflammation in the portal areas. Some liver lobules exhibited congestion and sinusoidal dilation compatible with venous occlusion clinically. CONCLUSIONS: We recommend Max IP and Min IP of CT images as simple and effective techniques to establish the diagnosis of BCS, especially in complicated cirrhotic patients, thereby avoiding invasive interventional procedures.

Long-term inhibition of hepatitis B virus in transgenic mice by double-stranded adeno-associated virus 8-delivered short hairpin RNA.

RNA interference (RNAi) was reported to block hepatitis B virus (HBV) gene expression and replication in vitro and in vivo. However, it remains a technical challenge for RNAi-based therapy to achieve long-term and complete inhibition effects in chronic HBV infection, which presumably requires more extensive and uniform transduction of the whole infected hepatocytes. To increase the in vivo transfection efficiency in liver, we used a double-stranded adeno-associated virus 8-pseudotyped vector (dsAAV2/8) to deliver shRNA. HBV transgenic mice were used as an animal model to evaluate the inhibition effects of the RNAi-based gene therapy. A single administration of dsAAV2/8 vector, carrying HBV-specific shRNA, effectively suppressed the steady level of HBV protein, mRNA and replicative DNA in liver of HBV transgenic mice, leading to up to 2-3 log(10) decrease in HBV load in the circulation. Significant HBV suppression sustained for at least 120 days after vector administration. The therapeutic effect of shRNA was target sequence dependent and did not involve activation of interferon. These results underscore the potential for developing RNAi-based therapy by dsAAV2/8 vector to treat HBV chronic infection, and possibly other persistent liver infections as well.