Spontaneous Resolution of Hemorrhagic Pseudocyst-Associated Pseudoaneurysm in Groove Pancreatitis.

Hemorrhagic pseudocyst (HP) and pseudocyst-associated pseudoaneurysms (PPs) are complications of pseudocyst. Angiography with embolization has been advocated as the first-line intervention for HP. A 47-year-old man with groove pancreatitis combined with HP near the pancreatic head was treated conservatively. He had relapsed pancreatitis with a newly identified pseudoaneurysm; however, the pseudocyst size was reduced. Although pseudoaneurysm was identified, angiography was not performed because there was no evidence of ongoing bleeding, and he was in a stable condition. Sphincterotomy and stent insertion in the pancreatic duct was applied to prevent relapsed pancreatitis with facilitation of the flow of pancreatic juice. He has done well during the 10-month follow-up, without recurrent pancreatitis. Angiography as an initial approach in HP and PPs may need to be more selective depending on the clinical presentation of the patient. A lysed clot within the strictured pancreatic duct during the healing process has been thought to be the cause of relapsed pancreatitis, and pancreatic sphincterotomy and stent insertion should be the preferred treatment methods.

Full-dose sofosbuvir plus low-dose ribavirin for hepatitis C virus genotype 2-infected patients on hemodialysis.

BACKGROUND/AIMS: New direct-acting antivirals have shown surprising success in the treatment of hepatitis C, not only in the general population, but also in difficult-to-treat cohorts. However, there is still limited data regarding direct-acting antivirals, including sofosbuvir (SOF), in the context of hemodialysis. The aim of this study was to investigate the safety and outcome of administering full-dose SOF (400 mg/day) plus low-dose ribavirin (RBV, 100 to 200 mg/day) in hemodialysis patients with hepatitis C virus (HCV) genotype 2 (GT2) infection. METHODS: Patients with chronic HCV GT2 infection and end-stage renal disease on maintenance hemodialysis treated with full-dose SOF plus low-dose RBV were retrospectively identified from a database of patients with HCV GT2 who were treated in Konkuk University Chungju Hospital between February 2017 and February 2018. Medical records were reviewed for demographics, medical history, laboratory data, and radiologic and electrocardiographic findings. RESULTS: All nine patients completed a full course of 12 weeks of treatment with a full-dose SOF plus low-dose RBV regimen. Two had compensated cirrhosis. Seven patients were treatment-naïve, and two had a relapse following previous interferon-based therapy. All patients had a sustained viral response at 12 weeks post-treatment. There was no discontinuation of treatment because of side effects. CONCLUSION: In hemodialysis patients with HCV GT2 infection, the full-dose SOF plus low-dose RBV regimen appears to be safe and well tolerated, and yields high rates of sustained virologic response.

Efficacy and Safety of Daclatasvir and Asunaprevir in Patients with Hepatitis C Virus Genotype 1b Infection on Hemodialysis.

Background/Aims: We evaluated the efficacy and safety of daclatasvir (DCV) and asunaprevir (ASV) in patients with chronic hepatitis C virus (HCV) infection on hemodialysis. Methods;: We performed a single-arm, multicenter prospective study. Twenty-one chronic hemodialysis patients with HCV infection were prospectively enrolled from February 2016 to April 2017. We evaluated the virological responses at weeks 4, 12, and 24 (end of treatment [EOT]) and the sustained virological response at 12 weeks after the EOT (SVR12). The tolerability and safety of the drugs were also assessed. Results: None of the 20 patients had the NS5A resistance-associated variant (NS5A RAV), and one patient was indeterminate for the NS5A RAV. Seventeen patients (80%) completed the 24 weeks of treatment with DCV and ASV. Four patients discontinued the study prior to week 12. In an intention-to-treat analysis, the SVR12 was 76.1%. In a per-protocol analysis, patients who completed DCV and ASV treatment achieved an SVR12 of 100%. DCV and ASV were well tolerated by the majority of patients. Three patients discontinued treatment due to adverse events (AEs) including dizziness, dyspnea, and neutropenia. The patient with indeterminate NS5A RAV showed viral breakthrough and discontinued treatment. Conclusions: DCV and ASV combination therapy in chronic hemodialysis patients with HCV infection achieved a high SVR12 rate with few AEs. To maximize the SVR12 rate, it is important to identify candidates by baseline RAV testing. Close monitoring of the safety and tolerability of DCV and ASV may be necessary in HCV-infected patients on hemodialysis. (ClinicalTrials.gov ID NCT02580474).

Efficacy and safety of sofosbuvir plus ribavirin for Korean patients with hepatitis C virus genotype 2 infection: A retrospective multi-institutional study.

BACKGROUND/AIMS: Sofosbuvir plus ribavirin is a standard treatment for patients infected with chronic hepatitis C virus (HCV) genotype 2 in Korea. The purpose of this study was to examine the efficacy and safety of this treatment in Korean patients with chronic HCV genotype 2 infection. METHODS: We retrospectively analyzed clinical data of patients treated with sofosbuvir plus ribavirin for chronic HCV genotype 2 from May 2016 to December 2017 at eight hospitals located in the Daejeon-Chungcheong area. RESULTS: A total of 172 patients were treated with sofosbuvir plus ribavirin. Of them, 163 patients completed the treatment, and 162 patients were tested for sustained virologic response 12 weeks after treatment discontinuation (SVR12). Mean age was 59.6±12.3 years (27-96), and 105 (64.4%) patients were female. Of the total patients, 49 (30.1%) were diagnosed with cirrhosis, and 31 of them were treated for 16 weeks. Sofosbuvir plus ribavirin was the first-line treatment for 144 (88.3%) patients. Eleven (6.7%) patients were intolerant to previous interferon-based treatment. Eight (5.0%) patients relapsed after interferon-based treatment. HCV RNA non-detection rate at 4, 8, and 12 weeks was 97.5%, 99.1%, and 99.3%, respectively, and SVR12 was 98.8% (161/163). During treatment, 18 (11.0%) patients had to reduce their administrated dose of ribavirin because of anemia. One patient stopped the treatment because of severe anemia. Other adverse events, including dizziness, indigestion, and headache, were found in 26 (16.0%) patients. CONCLUSION: A 12-16 week treatment with sofosbuvir plus ribavirin is remarkably effective and well tolerated in Korean patients with chronic HCV genotype 2 infection.

Management of hepatitis C viral infection in chronic kidney disease patients on hemodialysis in the era of direct-acting antivirals.

The advent of novel, direct-acting antiviral (DAA) regimens for hepatitis C viral (HCV) infection has revolutionized its treatment by producing a sustained virologic response of more than 95% with few side effects and no comorbidities in the general population. Until recently, ideal DAA regimens have not been available to patients with severe renal impairment and end-stage renal disease because there are limited data on the pharmacokinetics, safety, and efficacy of treatment in this unique population. In a hemodialysis context, identifying patients in need of treatment and preventing HCV transmission may also be a matter of concern. Recently published studies suggest that a combination of paritaprevir/ ritonavir/ombitasvir and dasabuvir, elbasvir/grazoprevir, or glecaprevir/pibrentasir successfully treats HCV infection in chronic kidney disease stage 4 or 5 patients with or without hemodialysis.

Clinical impact of the early alanine amininotransferase flare during tenofovir monotherapy in treatment-naïve patients with chronic hepatitis B.

BACKGROUND/AIMS: Little is known about the effect of early flares on response during first-line tenofovir disoproxil fumarate (TDF) treatment for chronic hepatitis B (CHB). The aim of this study was to investigate the incidence and outcome of early alanine aminotransferase (ALT) flare in treatment-naive patients with CHB during long-term TDF monotherapy. METHODS: One hundred eighty-one treatment-naive CHB patients were treated with a 300-mg once-daily dose of TDF for more than 12 weeks. Virological markers of hepatitis B virus (HBV) and biochemical data were measured at baseline and every 4-12 weeks during the therapy. The proportion of patients with undetectable HBV DNA level (< 100 copies/mL) was noted. RESULTS: The median age was 48.3 years and 122 patients (67.4%) were men. Hepatitis B envelope antigen (HBeAg) was positive in 101 patients (55.8%). No patient had cirrhosis. The median follow-up duration was 45 weeks (12-155 weeks). ALT flare (>5 × upper limit of the normal range) occurred in seven patients (3%) without viral breakthrough within the first 8 weeks after the start of TDF monotherapy. Among them, six patients were HBeAg-positive and one patient was HBeAg-negative. All cases of early ALT flares resolved within 4 weeks and virologic response was observed in all patients without interruption or discontinuation of treatment. CONCLUSIONS: Continuous TDF monotherapy was effective and safe in treatment-naive patients with CHB who experienced early ALT flares followed by a decrease in HBV DNA level.

Safety and efficacy of tenofovir in chronic hepatitis B-related decompensated cirrhosis.

AIM: To evaluate the safety and efficacy of tenofovir disoproxil fumarate (TDF) as a first-line therapy in decompensated liver disease. METHODS: We enrolled 174 chronic hepatitis B-related liver cirrhosis patients treated with 300 mg/d TDF at six Korean centers. Of the 174 cirrhosis patients, 57 were assigned to the decompensated cirrhosis group and 117 were assigned to the compensated cirrhosis group. We followed the patients for 12 mo and evaluated clinical outcomes, including biochemical, virological, and serological responses. We also evaluated changes in hepatic and renal function and compared the decompensated and compensated cirrhosis groups. RESULTS: The 1-year complete virological response (CVR) and Hepatitis B e antigen (HBeAg) seroconversion were seen in 70.2% and 14.2% in the decompensated cirrhosis group, respectively. The rates of HBeAg seroconversion/loss and ALT normalization at month 12 were similar in both groups. TDF treatment was also effective for decreasing the level of hepatitis B virus (HBV) DNA in both groups, but CVR was higher in the compensated group (88.9% vs 70.2%, P = 0.005). Tenofovir treatment for 12 mo resulted in improved Child-Turcotte-Pugh (CTP) and model for end-stage liver disease (MELD) scores in decompensated group (P < 0.001). Of the 57 decompensated patients, 39 (68.4%) achieved CTP class A and 27 (49.1%) showed improvement in the CTP score of 2 points after 12 mo of TDF. The observed rate of confirmed 0.5 mg/dL increases in serum levels of creatinine in the decompensated and compensated cirrhosis group were 7.0% and 2.5%, respectively (P < 1.000). CONCLUSION: TDF therapy in decompensated cirrhosis patients was effective for decreasing HBV DNA levels and improving hepatic function with relatively lower CVR than in compensated cirrhosis. Thus, physicians should carefully monitor not only renal function but also treatment responses when using TDF in decompensated cirrhosis patients.

Endoscopic Nasobiliary Drainage for Bile Leak Caused by Injury to the Ducts of Luschka.

A 51-year-old man underwent laparoscopic cholecystectomy for gallbladder stones. He had developed fever, chills, and abdominal pain four days after the procedure. In the drain tube, bile was persistently observed. An endoscopic retrograde cholangiopancreatography (ERCP) showed a leakage from the small duct into the right intrahepatic duct. We determined that the bile leak was caused by an injury to the ducts of Luschka. An endoscopic sphincterotomy (ES) using a 5-F nasobiliary tube (NBT) was performed, and the leak was resolved in five days. Herein, we report a bile leak caused by an injury to the ducts of Luschka after laparoscopic cholecystectomy. The leak was treated with ES using 5-F NBT, and the resolution of the leak was confirmed without repeated endoscopy.

The efficacy of tenofovir-based therapy in patients showing suboptimal response to entecavir-adefovir combination therapy.

BACKGROUND/AIMS: Before tenofovir (TDF) become available in South Korea, combination therapy with entecavir (ETV) and adefovir (ADV) was the most potent regimen for chronic hepatitis B (CHB) patients who fail to respond to rescue therapy for drug resistance. We analyzed the efficacy of ETV-ADV combination therapy and investigated the clinical and clonal results of TDF-based rescue therapy in CHB patients refractory to this combination. METHODS: We retrospectively reviewed the medical records of CHB patients treated for up to 3 years with ETV-ADV combination therapy as a rescue therapy for drug resistance. In cases refractory to this combination, clinical and clonal analyses were performed for TDF-based rescue therapy. RESULTS: The analysis was performed on 48 patients. Twelve patients achieved a virological response (VR) within 3 years. A VR was subsequently achieved in nine of the ten patients without a VR who switched to TDF monotherapy. A VR was also achieved in six of the seven patients who switched to lamivudine-TDF combination therapy, and in two of the two patients who switched to ETV-TDF combination therapy. In an in vitro susceptibility test, viral replication was detected with TDF monotherapy but not with ETV-TDF combination therapy. CONCLUSIONS: The efficacy of ETV-ADV combination therapy was insufficient in CHB patients who were refractory to rescue therapy. A more potent regimen such as ETV-TDF combination therapy may be considered in such refractory cases.

Noninvasive fibrosis marker can predict recurrence of hepatocellular carcinoma after radiofrequency ablation.

BACKGROUND/AIMS: Tumor recurrence after curative therapy is common for patients with hepatocellular carcinoma (HCC). As fibrosis and chronic inflammation contribute to the progression of HCC, we aimed to identify the predictive value of inflammatory and fibrosis markers for HCC recurrence after curative therapy using radiofrequency ablation (RFA). MATERIALS AND METHODS: We retrospectively reviewed the records of patients with HCC treated with RFA between October 2005 and September 2013. The median duration of follow-up was 40 months (4-95 months). Inflammatory and fibrosis markers and demographic and clinical data were analyzed by Cox proportional hazards model using univariate and multivariate analyses and longitudinal analysis. RESULTS: A total of 98 patients were included for analysis. There were 54 cases of HCC recurrence (55.1%). The aspartate aminotransferase-to-platelet ratio index (APRI; 2.3 ± 1.8 vs. 1.3 ± 1.4, P = 0.018) was significantly higher in the recurrence group than in the recurrence-free group. In multivariate analysis, APRI (hazard ratio, 2.64; confidence interval, 1.488-4.714; P = 0.001) was an independent risk factor for tumor recurrence. In particular, patients with APRI >1.38 showed a higher recurrence rate than patients with APRI ≤ 1.38 (P < 0.001). Longitudinal analysis showed persistently higher APRI values when assessed 12 months after RFA in patients who developed recurrence during follow-up than those who remained recurrence-free. CONCLUSIONS: These findings show that a high APRI value is associated with HCC recurrence after RFA. Therefore, APRI could play an important role in predicting HCC recurrence after RFA.

Primary anorectal malignant melanoma treated with endoscopic mucosal resection.

Anorectal melanoma is a rare neoplasm that accounts for less than 1-4% of anorectal malignant tumors. The main therapeutic modality for anorectal melanoma is surgical treatment, with abdominoperineal resection or wide local excision being the most common approaches. A 77-year-old male with a history of cerebral infarction and hypertension presented with anal bleeding. Here, we report a case of anorectal melanoma treated by endoscopic mucosal resection with adjuvant interferon therapy rather than surgical resection. The patient has been disease-free for 5 years after endoscopic treatment.

Clinical outcomes of patients with advanced hepatocellular carcinoma treated with sorafenib: a retrospective study of routine clinical practice in multi-institutions.

BACKGROUND: Sorafenib is an orally administered multikinase inhibitor with antiangiogenic and antiproliferative properties. The results of large clinical trials demonstrate that sorafenib prolongs survival and the time to progression of patients with advanced hepatocellular carcinoma (HCC). The aim of the present study was to determine the outcomes of such patients who were routinely treated with sorafenib at multi-institutions in Korea, in contrast to formal clinical trials. METHODS: Between August 2007 and March 2012, patients with advanced HCC in seven referral medical centers in Daejeon-Chungcheong Province of Korea were retrospectively enrolled to evaluate treatment response, survival, and tolerability following administration of sorafenib. The treatment response was assessed in accordance with the Response Evaluation Criteria in Solid Tumor 1.1 guidelines. RESULTS: Among 116 patients, 66 (57%) had undergone treatment for HCC, and 77 (66%) were accompanied with Child-Pugh A cirrhosis. The median duration of sorafenib treatment was 67 days (range 14-452 days). Median overall survival and median time to progression were 141 days and 90 days, respectively. Complete response, partial response, and stable disease were achieved for 0%, 2%, and 29% of patients, respectively. Overall median survival, but not the median time to progression, was significantly shorter for patients with Child-Pugh B cirrhosis compared with those with Child-Pugh A cirrhosis (64 days vs 168 days, P = 0.004). Child-Pugh B cirrhosis (P = 0.024) and a high level of serum alpha-fetoprotein (P = 0.039) were independent risk factors for poor overall survival. Thirty-nine (34%) patients experienced grade 3/4 adverse events such as hand-foot skin reactions and diarrhea that required dose adjustment. CONCLUSIONS: The clinical outcomes of sorafenib-treated patients with advanced HCC were comparable to those reported by formal clinical trial conducted in the Asia-Pacific region. Underlying hepatic dysfunction was the most important risk factor for shorter survival.

Reversible splenial lesion on the corpus callosum in nonfulminant hepatitis A presenting as encephalopathy.

Reversible focal lesions on the splenium of the corpus callosum (SCC) have been reported in patients with mild encephalitis/encephalopathy caused by various infectious agents, such as influenza, mumps, adenovirus, Varicella zoster, Escherichia coli, Legionella pneumophila, and Staphylococcus aureus. We report a case of a reversible SCC lesion causing reversible encephalopathy in nonfulminant hepatitis A. A 30-year-old healthy male with dysarthria and fever was admitted to our hospital. After admission his mental status became confused, and so we performed electroencephalography (EEG) and magnetic resonance imaging (MRI) of the brain, which revealed an intensified signal on diffusion-weighted imaging (DWI) at the SCC. His mental status improved 5 days after admission, and the SCC lesion had completely disappeared 15 days after admission.

Hepatitis B surface antigen levels at 6 months after treatment can predict the efficacy of lamivudine-adefovir combination therapy in patients with lamivudine-resistant chronic hepatitis B.

BACKGROUND/AIMS: Quantitation of hepatitis B surface antigen (HBsAg) is an increasingly popular method to determine the treatment response in chronic hepatitis B (CHB) patients. The clinical value of HBsAg level measurement during rescue therapy for lamivudine (LMV)-resistant CHB patients have not been evaluated to date. Therefore, this study investigated the correlation between HBsAg level and treatment response in LMV-resistant CHB patients treated with adefovir (ADV) add-on therapy. METHODS: LMV-resistant CHB patients treated with LMV-ADV combination therapy for over 2 years were included. HBsAg levels were measured at 6 month intervals until 1 year, and annually thereafter. Treatment response was assessed by determining the virological response (VR, undetectable HBV DNA levels) during treatment. RESULTS: Fifty patients were included, of which 40 showed a VR. HBsAg levels were not different significantly at baseline (4.0 vs. 3.6 Log10 IU/mL, P=0.072). However, the HBsAg level decreased after 6 months of treatment in patients with a VR and became different significantly between the groups thereafter (3.9 vs. 3.3 at 6 months, P=0.002; 3.8 vs. 3.2 at 1 year, P=0.004; 3.9 vs. 3.2 at 2 years, P=0.008; 3.7 vs. 3.1 at 3 years, P =0.020). CONCLUSIONS: The HBsAg level at 6 months after treatment can help predict treatment response.

Prevalence of renal dysfunction in patients with cirrhosis according to ADQI-IAC working party proposal.

BACKGROUND/AIMS: A revised classification system for renal dysfunction in patients with cirrhosis was proposed by the Acute Dialysis Quality Initiative and the International Ascites Club Working Group in 2011. The aim of this study was to determine the prevalence of renal dysfunction according to the criteria in this proposal. METHODS: The medical records of cirrhotic patients who were admitted to Konkuk University Hospital between 2006 and 2010 were reviewed retrospectively. The data obtained at first admission were collected. Acute kidney injury (AKI) and chronic kidney disease (CKD) were defined using the proposed diagnostic criteria of kidney dysfunction in cirrhosis. RESULTS: Six hundred and forty-three patients were admitted, of whom 190 (29.5%), 273 (42.5%), and 180 (28.0%) were Child-Pugh class A, B, and C, respectively. Eighty-three patients (12.9%) were diagnosed with AKI, the most common cause for which was dehydration (30 patients). Three patients had hepatorenal syndrome type 1 and 26 patients had prerenal-type AKI caused by volume deficiency after variceal bleeding. In addition, 22 patients (3.4%) were diagnosed with CKD, 1 patient with hepatorenal syndrome type 2, and 3 patients (0.5%) with AKI on CKD. CONCLUSIONS: Both AKI and CKD are common among hospitalized cirrhotic patients, and often occur simultaneously (16.8%). The most common type of renal dysfunction was AKI (12.9%). Diagnosis of type 2 hepatorenal syndrome remains difficult. A prospective cohort study is warranted to evaluate the clinical course in cirrhotic patients with renal dysfunction.

The Refit model for end-stage liver disease-Na is not a better predictor of mortality than the Refit model for end-stage liver disease in patients with cirrhosis and ascites.

BACKGROUND/AIMS: The modification of the Model for End-Stage Liver Disease (MELD) scoring system (Refit MELD) and the modification of MELD-Na (Refit MELDNa), which optimized the MELD coefficients, were published in 2011. We aimed to validate the superiority of the Refit MELDNa over the Refit MELD for the prediction of 3-month mortality in Korean patients with cirrhosis and ascites. METHODS: We reviewed the medical records of patients admitted with hepatic cirrhosis and ascites to the Konkuk University Hospital between January 2006 and December 2011. The Refit MELD and Refit MELDNa were compared using the predictive value of the 3-month mortality, as assessed by the Child-Pugh score. RESULTS: In total, 530 patients were enrolled, 87 of whom died within 3 months. Alcohol was the most common etiology of their cirrhosis (n=271, 51.1%), and the most common cause of death was variceal bleeding (n=20, 23%). The areas under the receiver operating curve (AUROCs) for the Child-Pugh, Refit MELD, and Refit MELDNa scores were 0.754, 0.791, and 0.764 respectively; the corresponding values when the analysis was performed only in patients with persistent ascites (n=115) were 0.725, 0.804, and 0.796, respectively. The significant difference found among the Child-Pugh, Refit MELD, and Refit MELDNa scores was between the Child-Pugh score and Refit MELD in patients with persistent ascites (P=0.039). CONCLUSIONS: Refit MELD and Refit MELDNa exhibited good predictability for 3-month mortality in patients with cirrhosis and ascites. However, Refit MELDNa was not found to be a better predictor than Refit MELD, despite the known relationship between hyponatremia and mortality in cirrhotic patients with ascites.

The impact of the hepatitis B virus polymerase rtA181T mutation on replication and drug resistance is potentially affected by overlapping changes in surface gene.

UNLABELLED: The emergence of drug-resistant hepatitis B virus (HBV) is a major problem for antiviral treatment in chronic hepatitis B infection. In this study, we analyzed the evolution of drug-resistant mutations and characterized the effects of the rtA181T and rtI233V mutations on viral replication and drug resistance. We performed a clonal analysis of the HBV polymerase gene from serum samples during viral breakthrough treated with antiviral agents. A series of mutant clones containing rtA181T and/or rtI233V mutations were constructed and determined the effect of these mutations on the replication ability and drug resistance. An in vitro study revealed that the effect of the rtA181T mutation on viral replication and drug resistance is dependent on the mutations in the overlapping surface gene. Compared to the rtA181T surface missense mutation (rtA181T/sW172S), the introduction of rtA181T surface nonsense mutation (rtA181T/sW172*) resulted in decreased viral replication and increased drug resistance. Complementation assay revealed that the truncated PreS1 is responsible for reduced replication of rtA181T/sW172* mutant. Moreover, the rtA181T/sW172* mutant exhibited a defect in viral particle secretion. The rtI233V mutation that emerged during adefovir therapy reduced viral replication and conferred resistance to adefovir. Our data suggest that the impact of the rtA181T mutation on replication and drug resistance differs based on the mutation status of the corresponding surface gene. The rtI233V mutation also affects replication ability and drug resistance. This observation suggests the need for genotypic analysis of overlapping surface genes to manage antiviral drug resistance if clinical isolates harbor the rtA181T mutation. IMPORTANCE: The emergence of drug-resistant HBV that are no longer susceptible to nucleos(t)ide analogues is a major problem for antiviral treatment in chronic hepatitis B infection. Among drug-resistant mutations, the single rtA181T mutation is known to confer cross-resistance to antiviral drugs. This mutation causes intermediate or reduced susceptibility to tenofovir. Moreover, the clinical occurrence of the rtA181T mutation during antiviral therapy is also high. Our study revealed that the effect of the rtA181T mutation on viral replication and drug resistance is dependent on the mutations in the overlapping surface gene. This observation suggests the need for genotypic analysis of overlapping surface genes to manage antiviral drug resistance if clinical isolates harbor the rtA181T mutation. We believe that our study will not only extend the understanding of the drug resistance mechanism, but it will also ultimately provide new treatment options for patients with multidrug resistant HBV.