A multiplex PCR assay for the simultaneous detection of five potexviruses infecting cactus plants using dual-priming oligonucleotides (DPOs) primers.

Five potexviruses, namely, cactus virus X (CVX), opuntia virus X, pitaya virus X (PiVX), schlumbergera virus X (SchVX) and zygocactus virus X (ZyVX), have been reported in cactus plants. In this report, a multiplex RT-PCR assay, based on specific dual-priming oligonucleotide (DPO) primers, was developed to detect these five viruses simultaneously in field samples. Using 18 field plants comprising 16 cactus species, these viruses were detected among nine of the 18 plants, including the simultaneous detection of CVX, PiVX, SchVX and ZyVX co-infecting an Aporocactus flagelliformis and a Notocactus leninghausii f. cristatus plant. The multiplex PCR assay was thus applied successfully in the field plants and it would be useful in the diagnosis of viral infections in cactus plants.

Effect of antiviral therapy in reducing perinatal transmission of hepatitis B virus and maternal outcomes after discontinuing them.

BACKGROUND/AIMS: There have been numerous efforts to reduce mother-to-child transmission (MTCT) of hepatitis B virus (HBV) with antiviral agents during pregnancy. However, there are limited data regarding the outcomes of pregnant women after delivery. This study was performed to evaluate the efficacy of antiviral agents in preventing MTCT of HBV and maternal long-term outcomes. METHODS: The HBV-infected pregnant women treated with antiviral agents to prevent MTCT were retrospectively reviewed. Forty-one pregnant women who received telbivudine or tenofovir during late pregnancy (28-34 week) were analyzed. Hepatitis B virus surface antibody (HBsAb) positivity was tested in 43 infants after 7 months of birth. Eleven mothers were followed >1 year after delivery. RESULTS: The mean HBV DNA titer before antiviral therapy was 8.67 (6.60-9.49) log copies/mL, and the median age at delivery was 32 years (range, 22-40). Eleven patients were treated with tenofovir and 30 with telbivudine. The median duration was 57 days (range, 23-100), and the median HBV DNA titer at birth was 5.06 log copies/mL (range, 2.06-6.50). Antiviral treatments were associated with significant HBV DNA reduction (P<0.001). Among 43 infants (two cases of twins), HBsAb was not detected in two, subsequently confirmed to have HBV infection. Biochemical flare was observed in two of 11 mothers followed >12 months, and an antiviral agent was administered. CONCLUSION: Antiviral treatment during late pregnancy effectively reduced MTCT. Long-term follow-up should be required in such cases. In addition, given that maternal biochemical flare occurred in 18% of mothers, re-administration of antiviral agents might be required.

Detection of Co-Infection of Notocactus leninghausii f. cristatus with Six Virus Species in South Korea.

Co-infection with two virus species was previously reported in some cactus plants. Here, we showed that Notocactus leninghausii f. cristatus can be co-infected with six different viruses: cactus mild mottle virus (CMMoV)-Nl, cactus virus X (CVX)-Nl, pitaya virus X (PiVX)-Nl, rattail cactus necrosis-associated virus (RCNaV)-Nl, schlumbergera virus X (SchVX)-Nl, and zygocactus virus X (ZyVX)-Nl. The coat protein sequences of these viruses were compared with those of previously reported viruses. CMMoV-Nl, CVX-Nl, PiVX-Nl, RCNaV-Nl, SchVX-Nl, and ZyVX-Nl showed the greatest nucleotide sequence homology to CMMoV-Kr (99.8% identity, GenBank accession NC_011803), CVX-Jeju (77.5% identity, GenBank accession LC12841), PiVX-P37 (98.4% identity, GenBank accession NC_024458), RCNaV (99.4% identity, GenBank accession NC_016442), SchVX-K11 (95.7% identity, GenBank accession NC_011659), and ZyVX-B1 (97.9% identity, GenBank accession NC_006059), respectively. This study is the first report of co-infection with six virus species in N. leninghausii f. cristatus in South Korea.

Aronia melanocarpa Extract Ameliorates Hepatic Lipid Metabolism through PPARγ2 Downregulation.

Nonalcoholic fatty liver disease (NAFLD) is a hepatic manifestation of metabolic syndrome. Studies have demonstrated that anthocyanin-rich foods may improve hyperlipidemia and ameliorate hepatic steatosis. Here, effects of Aronia melanocarpa (AM), known to be rich of anthocyanins, on hepatic lipid metabolism and adipogenic genes were determined. AM was treated to C57BL/6N mice fed with high fat diet (HFD) or to FL83B cells treated with free fatty acid (FFA). Changes in levels of lipids, enzymes and hormones were observed, and expressions of adipogenic genes involved in hepatic lipid metabolism were detected by PCR, Western blotting and luciferase assay. In mice, AM significantly reduced the body and liver weight, lipid accumulation in the liver, and levels of biochemical markers such as fatty acid synthase, hepatic triglyceride and leptin. Serum transaminases, indicators for hepatocyte injury, were also suppressed, while superoxide dismutase activity and liver antioxidant capacity were significantly increased. In FL83B cells, AM significantly reduced FFA-induced lipid droplet accumulation. Protein synthesis of an adipogenic transcription factor, peroxisome proliferator-activated receptor γ2 (PPARγ2) was inhibited in vivo. Furthermore, transcriptional activity of PPARγ2 was down-regulated in vitro, and mRNA expression of PPARγ2 and its downstream target genes, adipocyte protein 2 and lipoprotein lipase were down-regulated by AM both in vitro and in vivo. These results show beneficial effects of AM against hepatic lipid accumulation through the inhibition of PPARγ2 expression along with improvements in body weight, liver functions, lipid profiles and antioxidant capacity suggesting the potential therapeutic efficacy of AM on NAFLD.

On-treatment and off-treatment efficacy of entecavir in a real-life cohort of chronic hepatitis B patients.

BACKGROUND AND AIMS: Entecavir (ETV) is a potent nucleoside analogue with high genetic barrier to resistance. In this study, real-life clinical experiences in the long-term use of ETV and the durability of its off-treatment effectiveness were analyzed. MATERIALS AND METHODS: This study was based on a large real-life cohort of 2240 chronic hepatitis B patients treated with ETV between January 2006 and December 2012 using a centralized electronic data repository. RESULTS: Among 2240 patients, 804 patients were treatment naive and underwent ETV monotherapy. Their mean treatment duration was 712±493 days, with a cumulative proportion of patients achieving HBV DNA less than 300 copies/ml in 85.8, 95.7, and 97.6% at years 1, 2, and 3, respectively. Predictors for earlier virologic response were female sex, lower HBV DNA, higher alanine transaminase, lower platelet count, and HBeAg negativity at baseline. In patients who achieved virologic response and HBeAg loss, the cumulative relapse rate was 91.3% in 2 years after the cessation of treatment. During the treatment, 34 patients developed hepatocellular carcinoma, among whom 30 patients had cirrhosis before treatment initiation. ETV treatment showed efficient virologic response as the treatment duration was extended, but off-treatment efficacy was not durable, and the antiviral treatment showed some limitation in preventing hepatocellular carcinoma among liver cirrhosis patients, implying that treatment cessation should be taken into consideration more carefully. CONCLUSION: This study from a real-life cohort may provide data on treating chronic hepatitis B patients more close to everyday clinical practice.

Low skeletal muscle mass is associated with non-alcoholic fatty liver disease in Korean adults: the Fifth Korea National Health and Nutrition Examination Survey.

BACKGROUND: Sarcopenia and non-alcoholic fatty liver disease (NAFLD) share similar pathophysiological mechanisms, and the relationship between sarcopenia and NAFLD has been recently investigated. The study investigated whether low skeletal muscle mass is differentially associated with NAFLD by gender in Korean adults. METHODS: We conducted a cross-sectional analysis of the data from the Fifth Korea National Health and Nutrition Examination Survey. The skeletal muscle index (SMI) was obtained by the appendicular skeletal muscle mass divided by the weight. NAFLD was defined as a fatty liver index (FLI) ≥60 in the absence of other chronic liver disease. RESULTS: Among the included subjects, 18.3% (SE: 1.4%) in men and 7.0% (SE: 0.7%) in women were classified as having FLI-defined NAFLD. Most of the risk factors for FLI-defined NAFLD showed a significant negative correlation with the SMI in both genders. Multiple logistic regression analysis showed that low SMI was associated with FLI-defined NAFLD, independent of other metabolic and lifestyle parameters in both genders [males: odds ratio (OR)=1.35; 95% confidence interval (CI): 1.17-1.54; females: OR=1.36; 95% CI: 1.18-1.55]. The magnitude of the association between FLI-defined NAFLD and low SMI was higher in middle aged to elderly males (OR=1.50; 95% CI: 1.22-1.84) than in males less than 45 years of age (OR=1.25; 95% CI: 1.02-1.52) and in premenopausal females (OR=1.50; 95% CI: 1.12-2.03) than in postmenopausal females (OR=1.36; 95% CI: 1.20-1.54). CONCLUSIONS: Low SMI is associated with the risk of FLI-defined NAFLD independent of other well-known metabolic risk factors in both genders. This association may differ according to age group or menopausal status. Further studies are warranted to confirm this relationship.

A Decade-old Change in the Screening Rate for Hepatocellular Carcinoma Among a Hepatitis B Virus-infected Population in Korea.

BACKGROUND: Evaluating a change in the screening rate for hepatocellular carcinoma (HCC) is critical for understanding screening implementation, and whether targeted population groups are receiving proper screening. This study examined recent nationwide changes in HCC screening use among hepatitis B virus (HBV)-infected populations after the introduction of the Korean National Cancer Screening Program and predictors of screening adherence. METHODS: We analyzed 165 and 276 participants ≥40 years of age who were hepatitis B surface antigen-positive from 2001 (14,936 participants) to 2010-2011 (9159 participants) Korea National Health and Nutrition Examination Surveys, respectively. Demographic data, socioeconomic factors, and HCC screening use were collected by means of self-reported questionnaires. RESULTS: The rate of HCC screening within the previous 2 years increased significantly from 17.5% in 2001 to 40.3% in 2010-2011 (P < 0.0001). The rate of HCC screening use increased from 2001 to 2010-2011 in all study populations. Subjects who had a higher income status and were aware of their infection were more likely to have undergone recent HCC screening. CONCLUSIONS: This study showed a substantial increase in HCC screening in high-risk HBV-infected subjects from 2001 to 2010-2011. However, the HCC screening participation rate remained suboptimal despite the introduction of the nationwide screening program. Efforts should be made to identify high-risk individuals and increase attendance at HCC screening events among high-risk groups.

[Recurrence of multiple focal nodular hyperplasia in a young male patient].

Focal nodular hyperplasia (FNH) is the second most common benign hepatic tumor that is usually found in women. Diagnosis of FNH mainly depends on imaging studies such as color Doppler flow imaging, computed tomography, and magnetic resonance imaging. It is characterized by the presence of stellate central scar and is nowadays incidentally diagnosed with increasing frequency due to advances in radiologic imaging technique. FNH typically presents as a single lesion in 70% of cases and generally does not progress to malignancy or recur after resection. Herein, we report a case of a young male patient with recurrent multiple FNH who underwent surgical resection for presumed hepatic adenoma on computed tomography.

Can "healthy" normal alanine aminotransferase levels identify the metabolically obese phenotype? Findings from the Korea national health and nutrition examination survey 2008-2010.

BACKGROUND: There is no established parameter with which to screen metabolically obese phenotypes. AIM: The aim of the study was to revise the upper limit of normal (ULN) of serum alanine aminotransferase (ALT) and to investigate the predictive value of updated ALT levels for metabolic obese phenotype stratified according to body mass index (BMI). METHODS: We analyzed a nationally representative data from the Fourth Korea National Health and Nutrition Examination Survey. This cross-sectional study included 2,416 healthy people aged 33.9 ± 0.3 years. The ULN of healthy ALT level was set at the 95th percentile of the healthy population. A metabolic obese phenotype was defined as having insulin resistance or metabolic syndrome. A logistic regression analysis was performed to assess the odds ratio for a metabolic obese phenotype according to the healthy ALT level. RESULTS: The revised ULN of serum ALT level in healthy participants were 30 IU/L and 22 IU/L for males and females, respectively. Serum ALT level was higher in individuals with metabolic obesity compared with those without metabolic obesity in both genders, stratified according to BMI. After adjusting for age, BMI, smoking, alcohol drinking, and regular physical activity, unhealthy normal ALT levels (males 30-40 IU/L, females 22-40 IU/L) were significantly associated with metabolic obesity, especially in both obese and non-obese women. CONCLUSIONS: A newly revised threshold for ALT is proposed as a simple clinical metabolic parameter that can identify a metabolic obese phenotype. We suggest that people with unhealthy normal ALT levels may need further investigation for the presence of metabolic obesity.

A pilot study of autologous CD34-depleted bone marrow mononuclear cell transplantation via the hepatic artery in five patients with liver failure.

BACKGROUND AIMS: Many rodent experiments and human studies on stem cell therapy have shown promising therapeutic approaches to liver diseases. We investigated the clinical outcomes of five patients with liver failure of various causes who received autologous CD34-depleted bone marrow-derived mononuclear cell (BM-MNC) transplantation, including mesenchymal stromal cells, through the hepatic artery. METHODS: CD34-depleted BM-MNCs were obtained from five patients waiting for liver transplantation by bone marrow aspiration and using the CliniMACS CD34 Reagent System (Miltenyi Biotech, Bergisch Gladbach, Germany), and autologous hepatic artery infusion was performed. The causes of hepatic decompensation were hepatitis B virus (HBV), hepatitis C virus (HCV), propylthiouracil-induced toxic hepatitis and Wilson disease. RESULTS: Serum albumin levels improved 1 week after transplantation from 2.8 g/dL, 2.4 g/dL, 2.7 g/dL and 1.9 g/dL to 3.3 g/dL, 3.1 g/dL, 2.8 g/dL and 2.6 g/dL. Transient liver elastography data showed some change from 65 kPa, 33 kPa, 34.8 kPa and undetectable to 46.4 kPa, 19.8 kPa, 29.1 kPa and 67.8 kPa at 4 weeks after transplantation in a patient with Wilson disease, a patient with HCV, and two patients with HBV. Ascites decreased in two patients. One of the patients with HBV underwent liver transplantation 4 months after the infusion, and the hepatic progenitor markers (cytokeratin [CD]-7, CD-8, CD-9, CD-18, CD-19, c-Kit and epithelial cell adhesion molecule [EpCAM]) were highly expressed in the explanted liver. CONCLUSIONS: Serum albumin levels, liver stiffness, liver volume, subjective healthiness and quality of life improved in the study patients. Although these findings were observed in a small population, the results may suggest a promising future for autologous CD34-depleted BM-MNC transplantation as a bridge to liver transplantation in patients with liver failure.

Outcome after discontinuing antiviral agents during pregnancy in women infected with hepatitis B virus.

BACKGROUND: Women who are taking antiviral agents and become pregnant have several options that include, continuing therapy, ceasing drugs, or switching to safer drugs. However, there are limited data on the outcome in pregnant women after withdrawal of antiviral agents. OBJECTIVES: We aimed to investigate the outcome of stopping antiviral agents in pregnant women with chronic hepatitis B virus (HBV) infection. STUDY DESIGN: In this single-center, retrospective cohort study, 12 pregnant patients who had received antiviral therapy for HBV and cease drugs after awareness of pregnancy between 2003 and 2010 were enrolled. We retrospectively studied virologic and biochemical flares during pregnancy and postpartum period. RESULTS: Median age at pregnancy was 30.5 (range, 24-35) years, median duration of antiviral drug before pregnancy was 15.3 (range, 3.0-131.3) months, and median HBV DNA at withdrawal of therapy was 4.8 (range, 1.7-8.0) log(10) copies/mL. Eight out of twelve patients (66.7%) had a viral rebound after stopping antiviral drugs during pregnancy. Severe hepatitis flares, defined as a 5-fold increase in serum alanine aminotransferase (ALT), were observed in six patients (50%) during pregnancy. However, all of these patients spontaneously recovered without an event of hepatic decompensation. High pretreatment ALT was associated with severe hepatitis flares after cessation of therapy during pregnancy. Five patients with at least 1-year treatment before pregnancy maintained low hepatitis activity after delivery. CONCLUSIONS: Pregnant women with high pretreatment ALT or those treated less than 1 year before pregnancy have high risk of severe hepatitis flares after cessation of antiviral agents.

Clinical factors predictive of insufficient liver enhancement on the hepatocyte-phase of Gd-EOB-DTPA-enhanced magnetic resonance imaging in patients with liver cirrhosis.

BACKGROUND: Estimating liver parenchymal enhancement prior to gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance (MR) imaging is crucial to accurate detection and characterization of focal hepatic lesions. We aimed to clarify the factors predictive of liver enhancement in a relatively large sample of patients. METHODS: Gd-EOB-DTPA-enhanced MR images of 328 patients with liver cirrhosis (Child-Pugh class A in 223 patients, class B in 71 patients, and class C in 34 patients) were analyzed retrospectively. The liver parenchymal signal intensity (SI) was measured in pre-contrast T1-weighted images and hepatocyte phase images. The relative enhancement (RE) was calculated: (hepatocyte phase SI-pre-contrast SI)/pre-contrast SI. We analyzed the correlation between hepatic function parameters and RE. RESULTS: RE of patients with Child-Pugh A cirrhosis was significantly higher than that of patients with Child-Pugh B or C cirrhosis (both P < 0.001). Among various clinical factors, platelet count, prothrombin activity, albumin, sodium, total bilirubin, aspartate aminotransferase, Model for End-stage Liver Disease (MELD) score, MELD-Na score, Child-Pugh score, and the presence of ascites were significantly correlated with RE. A multiple stepwise regression analysis revealed that MELD-Na, albumin, and the presence of ascites were the only factors that predicted liver parenchymal enhancement on hepatocyte-phase images. CONCLUSION: The degree of liver parenchymal enhancement after Gd-EOB-DTPA administration was correlated with liver function parameters. Gd-EOB-DTPA-enhanced MR images require careful interpretation, particularly in patients with cirrhosis and clinical factors such as high MELD-Na score, hypoalbuminemia, or ascites.

Should lamivudine monotherapy be stopped or continued in patients infected with hepatitis B with favorable responses after more than 5 years of treatment?

Regarding the limited evidence for determining the optimal duration of antiviral treatment for hepatitis B, the long-term outcome of patients with favorable responses to over 5 years of lamivudine monotherapy was investigated. Two hundred seventy-one patients who had received lamivudine for at least 5 years were enrolled. Ultimately, 72 patients without YMDD mutations and showing hepatitis B virus (HBV) DNA levels <2.5 pg/ml after 5 years of treatment were analyzed. Mean treatment duration with lamivudine was 9.1 ± 2.6 years. During the treatment, HBeAg and HBsAg loss/seroconversion rates were 95 and 6.9%, respectively. Decompensation and hepatocellular carcinoma (HCC) developed in 2.8 and 6.9% of patients, respectively. Old age and cirrhosis were risk factors for HCC development. Finally, 11.1% of patients developed YMDD mutations after 8.3 ± 2.4 years of treatment. There was no hepatic decompensation among the patients who developed delayed YMDD mutations. Sixteen patients who achieved a complete response stopped lamivudine and four patients showed relapses 10.3 ± 8.5 months after stopping lamivudine. Relapsed patients had more cirrhotic livers and higher rates of HBeAg positivity at 5 years than patients who maintained complete response. The present study suggests that patients who do not develop YMDD mutations over 5 years of treatment with lamivudine may continue lamivudine monotherapy until the loss of HBsAg. However, even for the patients showing favorable response over 5 years of treatment, those in older ages, with cirrhosis or who show poor HBeAg responses should be on careful monitoring to detect the development of viral mutations, relapse and even HCC.

Predictive value of ¹8F-fluorodeoxyglucose PET/CT for transarterial chemolipiodolization of hepatocellular carcinoma.

AIM: To investigate the correlation of ¹8F-fluorodeoxyglucose (¹8F-FDG) positron emission tomography (PET) with clinical features and the prediction of treatment response. METHODS: A total of 83 hepatocellular carcinoma (HCC) patients undergoing ¹8F-FDG PET before transarterial chemolipiodolization with systemic chemo-infusion between October, 2006 and May, 2009 were retrospectively enrolled. The patients included 68 men and 15 women (mean age, 60 ± 10.7 years). The effect of (18)F-FDG-monitored PET uptake on clinical features and on the evaluated treatment response was ascertained with modified Response Evaluation Criteria in Solid Tumors. The PET parameters of maximal standardized uptake value of the tumor (Tsuv(max)), the ratio of the tumor maximal standardized uptake value (SUV) to the liver maximal SUV (Tsuv(max)/Lsuv(max)) and the ratio of tumor maximal SUV to the liver mean SUV (Tsuv(max)/Lsuv(mean)) were tested as predictive factors. RESULTS: Among the 3 SUV parameters, the Tsuv(max)/Lsuv(mean) ratio (cutoff value of 1.90) was significantly associated with tumor burden including tumor size, tumor number, α-fetoprotein levels and tumor stage (P < 0.001, P = 0.008, P = 0.011, P < 0.001, respectively). The objective response rates in patients with a high SUV ratio (≥ 1.90) were significantly better than those with a low SUV ratio (< 1.90) (P = 0.020). The overall survival rates of patients exhibiting a low Tsuv(max)/Lsuv(mean) ratio (< 1.90) and those with a high SUV ratio (≥ 1.90) was 38.2 and 10.3 mo, respectively (P < 0.01). However, the time to progression showed no significant difference between the groups (P = 0.15). CONCLUSION: ¹8F-FDG PET can be an important predictor of HCC treatment. In particular, the Tsuv(max)/Lsuv(mean) ratio (cutoff value of 1.90) can provide useful information in treatment prognosis for HCC patients treated with locoregional therapy.

Comparative study between doxorubicin-eluting beads and conventional transarterial chemoembolization for treatment of hepatocellular carcinoma.

BACKGROUND & AIMS: Transarterial chemoembolization (TACE) is a widely used treatment for hepatocellular carcinoma. In order to maximize its therapeutic efficacy, doxorubicin-loaded drug-eluting beads have been developed to deliver higher doses of the chemotherapeutic agent and to prolong contact time with the tumor. The purpose of this study was to evaluate the efficacy and safety of drug-eluting bead (DC bead®) TACE in comparison with conventional TACE (cTACE). METHODS: A total of 129 patients who underwent TACE between August 2008 and February 2011 were enrolled. We compared HCC patients who underwent TACE with DC bead® (n=60) to controls who received cTACE (n=69). The primary end points were treatment response and treatment-related adverse events. The secondary end point was time to progression. RESULTS: The treatment response in the DC bead® group was significantly higher than that of the cTACE group (p<0.001). The time to progression was significantly better in the DC bead® group than in the cTACE group (11.7 and 7.6months, respectively, p=0.018). Subgroup analysis showed that in intermediate-stage HCC, DC bead® treatment resulted in a significantly better treatment response and longer time to progression than cTACE (p<0.001 and 0.038, respectively). However, there was no statistically significant difference in liver toxicity between the DC bead® and cTACE group (p>0.05). CONCLUSIONS: TACE with DC bead® showed better treatment response and delayed tumor progression compared with cTACE. There was no significant difference in hepatic treatment-related toxicities. DC bead® TACE thus appears to be a feasible and promising approach to the treatment of HCC.

Family history influences the early onset of hepatocellular carcinoma.

AIM: To evaluate the relationship between a positive family history of primary liver cancer and hepatocellular carcinoma (HCC) development in Korean HCC patients. METHODS: We studied a total of 2242 patients diagnosed with HCC between January 1990 and July 2008, whose family history of primary liver cancer was clearly described in the medical records. RESULTS: Of the 2242 patients, 165 (7.4%) had a positive family history of HCC and 2077 (92.6%) did not. The male to female ratio was 3.6:1, and the major causes of HCC were chronic hepatitis B virus (HBV) infection in 75.1%, chronic hepatitis C virus infection in 13.2% and alcohol in 3.1%. The median ages at diagnosis in the positive- and negative-history groups were 52 years (range: 29-79 years) and 57 years (range: 18-89 years), respectively (P < 0.0001). Furthermore, among 1713 HCC patients with HBV infection, the number of patients under 45 years of age out of 136 patients with positive family history was 26 (19.1%), whereas those out of 1577 patients with negative family history was 197 (12.5%), suggesting that a positive family history may be associated with earlier development of HCC in the Korean population (P = 0.0028). CONCLUSION: More intensive surveillance maybe recommended to those with a positive family history of HCC for earlier diagnosis and proper management especially when HBV infection is present.

Endoscopic submucosal dissection of gastric neoplasia involving the pyloric channel by retroflexion in the duodenum.

BACKGROUND: Tumors involving the pyloric channel have been considered as difficult lesions for successful endoscopic resection. We studied the feasibility of endoscopic submucosal dissection (ESD) using retroflexion in the duodenum to resect the gastric neoplasia involving the pyloric channel. AIM: To compare the treatment outcomes of a new ESD technique using retroflexion to those without retroflexion in the duodenum. METHODS: Twenty-four cases of gastric neoplasia involving the pyloric channel were resected by ESD. In 14 cases, ESDs were performed from both the antrum and duodenal bulb using retroflexion (retroflexion group). In ten cases, ESDs were performed conventionally only from the side of the antrum (conventional group). We compared the outcomes between the two methods. RESULTS: There was no complication regarding retroflexion in the duodenum. In the retroflexion group, the en bloc and complete resection rate was 100%, respectively. The rate of complete resection was significantly higher in the retroflexion group than in the conventional group (P = 0.01). In the conventional group, three patients with early gastric cancer underwent additional subtotal gastrectomy for positive lateral margin, and one patient with perforation was treated additionally by surgical repair. In the retroflexion group, microperforation and pyloric channel stenosis occurred in one patient, which resolved with conservative treatment. CONCLUSIONS: Tumors involving the pyloric channel could be successfully resected by ESD using retroflexion in the duodenum without severe complication. This technique appears to be a feasible and effective method for the treatment of tumors involving the pyloric channel.