Jae-Jun Shim

Recent trends in hepatitis B virus infection in the general Korean population

Background/Aims Hepatitis B virus (HBV) is the major cause of chronic liver disease in Korea, but viral prevalence has decreased because of hepatitis B vaccination programs. In this study, we investigated longitudinal changes in HBV in fection in the general Korean population. Methods HBV surface antigen (hepatitis B surface antigen, HBsAg) seropositivity was assessed from the Korea National Health and Nutrition Examination Survey (I to V). In total, 50,140 subjects were tested for serum HBsAg positivity over a period of 12 years (1998 to 2010). Results The prevalence of HBsAg seropositivity decreased over the study period. The rates of HBsAg carriers were 4.61% in 1998, 4.60% in 2001, 3.69% in 2005, 3.01% in 2008, and 2.98% in 2010 (p < 0.0001). The reduction in HBV infection rates was more prominent in younger age groups. Among teenagers (10 to 19 years), the percentage of HBsAg carriers decreased from 2.2% in 1998 to 0.12% in 2010 (p < 0.0001). Among those aged 10 to 39 years, the percentage of HBV infection decreased from 4.72% in 1998 to 2.29% in 2010 (p < 0.0001). However, no decreasing trend in HBsAg positivity was observed among those aged 50 or older (p > 0.05). Neither gender nor socioeconomic status were associated with the decreased prevalence of HBsAg carriers. Conclusions HBV infection has decreased in the Korean population since the advent of vaccination programs. However, the decrease is limited to the younger population, and viral persistence remains in the middle-aged and older population.

Prevalence of Proximal Serrated Polyps and Conventional Adenomas in an Asymptomatic Average-Risk Screening Population

Background/Aims Detection of proximal serrated polyps (PSPs) is increasingly recognized as a new qualitative target for colonoscopy. The aims of this study were to assess the detected prevalence of PSPs and synchronous adenomas in an asymptomatic average-risk screening cohort and to evaluate potential factors associated with detection of PSPs. Methods The study included 1,375 asymptomatic average-risk Korean patients (aged 50 years or older) who underwent screening colonoscopy. In total, 1,710 polyps were evaluated pathologically. Results The overall PSP detection rate (PSPDR) was low at 3.1%, despite high polyp (54.0%) and adenoma detection rates (ADRs, 43.5%). ADR did not correlate with PSPDR, but it was strongly correlated with PDR (r=0.810; p<0.001). Patients with PSPs were more likely to have longer withdrawal time and more proximal colon adenomas than patients without PSPs (adjusted odds ratio [OR], 1.19; 95% confidence interval [CI], 1.09 to 1.31; p<0.001) (adjusted OR, 2.03; 95% CI, 1.06 to 3.88; p=0.031, respectively). Conclusions The detected prevalence of PSPs was low (<5%) in an asymptomatic average-risk screening Korean population, despite the high prevalence of conventional adenomas. A longer mucosal inspection of the proximal colon may serve as a practical method to enhance detection of PSPs.

Sacroiliitis Is Common in Crohn's Disease Patients with Perianal or Upper Gastrointestinal Involvement

BACKGROUND/AIMS Sacroiliitis (SI) is one of the most frequent extraintestinal manifestations in inflammatory bowel disease (IBD) patients, but the exact prevalence has not been evaluated in Asia. There are few data on the association between SI and other clinical features of IBD. The prevalence of SI was evaluated using computed tomography (CT) and the phenotypic parameters associated with SI in Korean IBD patients were determined. METHODS Eighty-two patients with ulcerative colitis (UC) and 81 patients with Crohns disease (CD) were evaluated clinically. The presence of SI was evaluated using bone window setting of abdomino-pelvic CT images by two radiologists. RESULTS The prevalence rates of SI were 12.2% and 21.0% in the UC and CD groups, respectively. There was no relationship between the localization or extent of intestinal inflammation and the presence of SI in the UC group. Multivariate analyses confirmed that perianal and upper-gastrointestinal (from the mouth through to the jejunum) diseases were associated with the occurrence of SI in the CD group (p=0.026 and p=0.047, respectively). CONCLUSIONS SI was as common among Korean IBD patients as among Western patients. Perianal or upper-gastrointestinal involvement is associated with SI in CD patients.

The prevalence of elevated alanine transaminase and its possible causes in the general Korean population.

Goals: The goal of the study was to investigate the current prevalence and causes of elevated alanine transaminase (ALT) in the general Korean population. Background: Incidentally elevated ALT is frequently found because of increasing access to hospitals and blood tests. Study: A population-based cross-sectional study was carried out based on the Fourth Korean National Health and Nutrition Examination Survey (K-NHANES). Eligible subjects included 7894 men and 10,197 women. We defined elevated ALT as >43 U/L. Among the subjects with elevated ALT, those who consumed alcohol, had the hepatitis B surface antigen (HBsAg), were obese (body mass index ≥25 kg/m2), were insulin resistant (the homeostasis model assessment—insulin resistance), or had metabolic syndrome (MetS) were investigated. Results: The prevalence of elevated ALT was 7.4% in the Korean population. Increased ALT was more common in men (11.6%) than in women (3.1%) (P<0.001). Subjects with hypertension, diabetes, dyslipidemia (cholesterol ≥240 mg/dL or triglycerides ≥150 mg/dL), obesity, significant consumption of alcohol, HBsAg positive, or MetS were associated with elevated ALT (all P<0.001). The most common potential cause of elevated ALT was metabolic disorder (MetS, obesity, and/or insulin resistance), which comprised 74.9% of cases. MetS was found in 42.7% of men and 49.7% of women (P=0.031). Excess alcohol drinking was found in 29.6% of men and 7.5% of women with elevated ALT (P<0.001). HBsAg positivity was found in only 6% of subjects. Conclusions: Incidentally elevated ALT is common in the Korean population. It is associated with metabolic disorders (obesity, insulin resistance, or MetS) in the majority of patients. This finding suggests that nonalcoholic fatty liver disease might be the most common cause of elevated ALT in the general Korean population.

Effect of interlayer exchange coupling on magnetic chiral structures

We numerically investigated the effect of interlayer exchange coupling on magnetic chiral structures, such as a helical/cycloidal spin structure and magnetic skyrmion crystal (SkX), which are produced in a magnetic system involving the Dzyaloshinskii-Moriya interaction (DMI). We report the existence of a phase transition where the length scale of magnetic structure discontinuously changes, and that there can be a novel magnetic structure around the phase boundary that exhibits double-ordering lengths of magnetic structure. Therefore, the system has multiple ground phases determined by the ratio of interlayer exchange coupling strength and DMI strength. Furthermore, we investigated the critical condition of the external perpendicular field required for the SkX. The critical field is significantly reduced under the effect of interlayer exchange coupling, which can stabilize the SkX without the external field.

Clinical parameters including serum pepsinogen level and management strategy in patients with premalignant gastric dysplasia.

Objective Surgical or endoscopic resection is recommended for the management of gastric high-grade dysplasia (HGD). However, there are no proper guidelines for the management of gastric low-grade dysplasia (LGD). We evaluated clinical parameters, histological results, and endoscopic follow-up to find a management strategy of LGD. Methods A total of 590 patients with LGD, HGD, functional dyspepsia (FD), and early or advanced gastric cancer (EGC or AGC, respectively) were consecutively enrolled. We examined the association of clinical parameters including low serum pepsinogen (PG) I/II ratio of 3.0 or less with the disease phenotypes. Histological results between initial forceps biopsy and final endoscopic mucosal resection (EMR) or endoscopic submucosal dissection (ESD) specimens were compared. Complications and recurrence were evaluated after EMR or ESD. Results The PG I/II ratio in FD was 4.2±1.7 (mean±SD), but was significantly lower in LGD (2.8±1.6, P<0.0001). The PG I/II ratio was not any lower in the HGD, EGC, and AGC groups. In patients with FD having a PG I/II ratio of 3.0 or less, multiple logistic regression analysis showed smoking habits and high salt intake were independent risk factors for gastric dysplasia or gastric cancer. About 11% (n=8/70) of LGD lesions were upgraded to HGD (6/70) or EGC (2/70) after EMR or ESD. Neither serious complications nor recurrence at the primary site after EMR or ESD were found in LGD. Conclusion It is proposed that endoscopic resection followed by endoscopic surveillance might be a beneficial strategy for patients with LGD having a PG I/II ratio of 3.0 or less.

Liver cirrhosis stages and the incidence of hepatocellular carcinoma in chronic hepatitis B patients receiving antiviral therapy

Abstract Objectives: Long-term antiviral therapy decreases the risk of hepatocellular carcinoma (HCC) in patients with chronic hepatitis B (CHB), however, it cannot eliminate the risk. We investigated the incidence of HCC at different stages of liver cirrhosis (LC) and identified clinical predictors for HCC development during antiviral therapy. Methods: The data from 356 treatment-naïve patients aged 40 to 69 years without a history of HCC who had received entecavir for ≥6 months were collected retrospectively. The incidence of HCC was evaluated in patients with CHB only, with LC without varices (stage 1), with varices (stage 2), and with ascites (stage 3). Results: The median follow-up period was 3.6 years. In total, 45 patients (12.6%) developed HCC. The annual incidence rates of HCC in patients with CHB only or LC in stages 1, 2, and 3 were 0.4%, 2.6%, 9.8%, and 6.7%, respectively. In multivariate analyzes, LC at stage 2 (hazard ratio [HR] 17.16, 95% confidence interval [C.I.] 3.93–75.01, p < .001), alcohol consumption (HR 3.84, 95% C.I. 1.99–7.39, p < .001), and older age (HR 1.06, 95% C.I. 1.01–1.11, p = .010) were significantly associated with HCC development. The risk decreased in those who stopped drinking after 2 years of abstinence (p = .0314). Conclusions: LC with significant portal hypertension (varices or ascites), alcohol consumption, and older age at the time of starting antiviral therapy are independent predictors for future HCC development.

Serum alanine aminotransferase level and liver-related mortality in patients with chronic hepatitis B: A large national cohort study

The serum alanine aminotransferase (ALT) level has been used to identify at‐risk patients with chronic hepatitis B (CHB) who need antiviral therapy. However, the level associated with increased liver‐related mortality requiring active treatment is still unclear.

Trends in healthcare costs and utilization for inflammatory bowel disease from 2010 to 2014 in Korea: A nationwide population-based study

Data regarding health‐care costs and utilization for inflammatory bowel disease (IBD) at the population level are limited in Asia. We aimed to investigate the nationwide prevalence and health‐care cost and utilization of IBD in Korea.

Abstract 2588: Prediction of the 5-year risk of hepatocellular carcinoma during long-term antiviral therapy in the general Korean population

Proceedings: AACR 107th Annual Meeting 2016; April 16-20, 2016; New Orleans, LA Oral antiviral therapy using nucleos(t)ide analogues can decrease risk for hepatocellular carcinoma (HCC) in patients with chronic hepatitis B. However, wide use of antiviral therapy is limited by stringent treatment indications in many countries. We compared preventive effect of antiviral therapy on HCC development between current and new extended indication for the treatment. We established Korean cohort with chronic hepatitis B virus (HBV) infection using the fifth National Health and Nutrition Examination Survey (KNHANES). The cohort represented 993,872 subjects with chronic HBV infection more than 40 years in Korea. We estimated five-year risk of HCC before and after antiviral therapy using a HCC prediction score (REACH-B). The National Health Insurance (NHI) in Korea, the European Association for the Study of the Liver (EASL) guideline, and a new extended indication were compared. During a 5-year period, predicted HCC cases were 2,725 per 100,000 individuals (0.55% / year). When the cohort was treated under the Korean NHI indication, EASL, and new extended indication, HCC risk decreased to 2,531 (-7.1%), 2,089 (-23.3%), and 1,122 (-58.8%) cases per 100,000 individuals, respectively (P < 0.0001). As participation rate in antiviral therapy among eligible patients increased every 10%, HCC risk decreased to -0.74%, -2.39%, and -5.87%, respectively. New extended indication could decrease HCC risk eight times more than the current Korean NHI indication. Prediction of HCC development among chronic HBV infection is feasible in the virtual population level. Considering the large preventive effect of antiviral therapy, the treatment indications should be revised to increase eligible patients. View this table: Indications for antiviral treatment used in this study and predicted reduction of HCC risk Citation Format: Jae-Jun Shim, In Hwan Oh, Jung Wook Kim, Chang Kyun Lee, Jae Young Jang, Ju-Seog Lee, Byung-Ho Kim. Prediction of the 5-year risk of hepatocellular carcinoma during long-term antiviral therapy in the general Korean population. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2588.