Jong In Yang

Hepatic steatosis index: A simple screening tool reflecting nonalcoholic fatty liver disease

BACKGROUND/AIMS To optimize management of nonalcoholic fatty liver disease (NAFLD), a simple screening tool is necessary. In this study, we aimed to devise a simple index of NAFLD. STUDY A cross-sectional study with 10,724 health check-up subjects (5362 cases with NAFLD versus age- and sex-matched controls) was conducted. Study subjects were randomly assigned to a derivation cohort or a validation cohort. RESULTS Multivariate analysis indicated that high serum alanine aminotransferase (ALT) to serum aspartate aminotransferase (AST) ratio, high body mass index (BMI), and diabetes mellitus were independent risk factors of NAFLD (all P<0.001). Using these variables, a formula was derived by a logistic regression model: hepatic steatosis index (HSI)= 8 x(ALT/AST ratio)+BMI (+2, if female; +2, if diabetes mellitus). HSI had an area under receiver-operating curve of 0.812 (95% confidence interval, 0.801-0.824). At values of <30.0 or >36.0, HSI ruled out NAFLD with a sensitivity of 93.1%, or detected NAFLD with a specificity of 92.4%, respectively. Of 2692 subjects with HSI <30.0 or >36.0 in the derivation cohort, 2305 (85.6%) were correctly classified. HSI was validated in the subsequent validation cohort. CONCLUSION HSI is a simple, efficient screening tool for NAFLD that may be utilized for selecting individuals for liver ultrasonography and for determining the need for lifestyle modifications.

Prospective evaluation of a new stool antigen test for the detection of Helicobacter pylori, in comparison with histology, rapid urease test, 13C-urea breath test, and serology

Background and Aims:  This study aimed to evaluate the efficacy of a new polyclonal enzyme immunoassay for the detection of Helicobacter pylori (H. pylori) antigen in stool by determination of the optimal cut‐off value in the screening population.

Clinical features and prognosis of early colorectal cancer treated by endoscopic mucosal resection.

Background and Aims:  The incidence of early colorectal cancer (ECC) has been increasing. The aim of this study was to evaluate the clinical outcome and prognosis of ECC treated by endoscopic mucosal resection (EMR).

The serum vitamin D level is inversely correlated with nonalcoholic fatty liver disease

Background/Aims: A low vitamin D level has been associated with metabolic syndrome and diabetes. However, an association between a low vitamin D level and nonalcoholic fatty liver disease (NAFLD) has not yet been definitively established. This study aimed to characterize the relationship between a vitamin D level and NAFLD in Korea. Methods: A cross-sectional study involving 6,055 health check-up subjects was conducted. NAFLD was diagnosed on the basis of typical ultrasonographic findings and a history of alcohol consumption. Results: The subjects were aged 51.7±10.3 years (mean±SD) and 54.7% were female. NAFLD showed a significant inverse correlation with the vitamin D level after adjusting for age and sex [odds ratio (OR)=0.85, 95% confidence interval (CI)=0.75–0.96]. The age- and sex-adjusted prevalence of NAFLD decreased steadily with increasing vitamin D level [OR=0.74, 95% CI=0.60–0.90, lowest quintile (≤14.4 ng/mL) vs highest quintile (≥28.9 ng/mL), p for trend <0.001]. Multivariate regression analysis after adjusting for other metabolic factors revealed that NAFLD showed a significant inverse correlation with both the vitamin D level (>20 ng/mL) [OR=0.86, 95% CI=0.75-0.99] and the quintiles of the vitamin D level in a dose-dependent manner (p for trend=0.001). Conclusions: The serum level of vitamin D, even when within the normal range, was found to be inversely correlated with NAFLD in a dose-dependent manner. Vitamin D was found to be inversely correlated with NAFLD independent of known metabolic risk factors. These findings suggest that vitamin D exerts protective effects against NAFLD.

Initial Report of the Korean Organ Transplant Registry: The First Report of National Kidney Transplantation Data

PURPOSE A national organ transplant registry is an indispensable organizational requirement for patient care, research, and planning. Even though the Korean Network for Organ Sharing (KONOS) has established a database for a waiting list, organ allocation, and incidence of organ transplantation since 2000, an integrated registry including post-transplantation data is needed for better understanding of organ transplantation. Recently, the Korean Society for Transplantation (KST) and the Korean Center for Disease Control (KCDC) designed a web-based organ transplant registry, named the Korean Organ Transplant Registry (KOTRY). As an initial project of KOTRY, we retrospectively analyzed kidney transplantations (KTs) performed in 2009 and 2010. METHODS A total of 2292 KTs (91.9%) from 46 hospitals (80.7%) were collected and analyzed. Ninety-five elements related to KT were selected and analyzed. RESULTS Proportions of male recipients and retransplantations were 58.4% and 7.1%, respectively. Even though glomerulonephritis was the most common cause of end-stage renal disease (ESRD) (28.4%), the number of diabetic nephropathy cases was increasing. The living donor (LD) to deceased donor (DD) ratio was 1.69:1. Because of a serious organ shortage in Korea, DD kidneys with a low initial estimated glomerular filtration rate (eGFR) of <45 mL/min/1.73 m(2) (21.2%) and expanded criteria donors (ECDs; 18.3%) are frequently used. Other noticeable findings are the increasing number of wife donors and ABO-incompatible (ABOi) transplants for O(+) recipients. CONCLUSIONS The epidemiological profile of transplantation is different from country to country. The number of organ transplantations in East Asian countries is rapidly growing, however, there are few epidemiological data about this region in the literature. With the establishment of KOTRY, it was possible to present the first nationwide epidemiological data of Korean KTs.

Seroprevalence of Hepatitis A and Associated Socioeconomic Factors in Young Healthy Korean Adults

BACKGROUND/AIMS An epidemiologic shift of hepatitis A virus (HAV) seroprevalence is expected due to an improvement in socioeconomic status in young adults in Korea. We investigated the age-specific seroprevalence and socioeconomic factors associated with HAV seropositivity in young, healthy Korean adults. METHODS Between March 2009 and February 2010, a total of 5,051 persons from 20 to 49 years of age presenting for a health check-up were included and responded to a questionaire. The seroprevalence of HAV was investigated by measuring immunoglobulin G (IgG) anti-HAV. A total of 984 pairs of cases and age- and sex-matched controls were analyzed for associated socioeconomic factors. RESULTS The prevalence of seropositive HAV was 6.2% in the 20 to 29 age range, 33.1% in the 30 to 39 range and 82.4% in the 40 to 49 range (p<0.001). There were no significant differences in any group according to gender. A multivariate analysis for paired cases indicated that HAV seropositivity was significantly higher in the low monthly income (below five million won, approximately 4,300 dollars) group and the Helicobacter pylori (H. pylori)-positive group (odds ratio [OR], 1.65; 95% confidence interval [CI], 1.27-2.14; p<0.001; OR, 1.45; 95% CI, 1.19-1.76; p<0.001, respectively). CONCLUSIONS HAV seropositivity in young adults presenting for a health checkup appears to be decreasing, and the prevalence was significantly higher in the low monthly income group and the H. pylori-positive group.

Utility of QuantiFERON-TB Assay for Prediction of Tuberculosis Development in Kidney Transplant Patients in an Intermediate- Tuberculosis-Burden Country: Lack of Evidence for Enhanced Prediction for Short-Term Tuberculosis Development

INTRODUCTION Although a latent tuberculosis (TB) infection is a risk factor for active TB, the diagnosis of latent TB infection is difficult in end-stage renal disease patients. PATIENTS AND METHODS We retrospectively compared the results of the QuantiFERON-TB (QFT) test and the tuberculin skin test in patients on the waiting list for kidney transplantation (KT), and investigated whether the QFT test can predict TB development in KT recipients in an intermediate-TB-burden country. RESULTS The incidence of post-KT TB was 283 cases/100,000 patient-years among 1274 KT recipients at the Seoul National University Hospital. The overall standardized incidence ratio of TB was 4.358 compared with the general population. A past history of TB infection, smoking history, myocardial infarction after KT, and pneumocystis infection were significant predictors of subsequent TB development (adjusted odds ratios were 3.618, 2.959, 9.993, and 5.708, respectively). Among the 129 recipients who had the QFT test, 42 patients (32.5%) had positive a QFT. At a median follow-up of 8.4 ± 6.8 months, 1 patient with positive QFT results developed TB after KT, and 1 of the 87 patients with negative QFT results developed TB after KT. In both of these 2 cases, active TB developed despite isoniazid prophylaxis. Among 272 patients on the waiting list for KT, the tuberculin skin test and QFT were positive in 22.8% and 35.3%, respectively. The degree of agreement between the 2 tests was poor (κ = 0.352). CONCLUSIONS The QFT test did not predict subsequent short-term TB development. Furthermore, a long-term and larger-scale study is needed to confirm our results.

Kidney Transplantation Using Expanded Criteria Donors in Korea

BACKGROUND Use of expanded criteria donor (ECD) grafts seeks to solve the organ shortage. We investigated the current status of donor selection and transplantation outcomes. METHODS We retrospectively analyzed 791 kidney transplantations performed between 1997 and 2009. An expanded criteria deceased donor (ECDD) was defined as an individual who fulfilled the United Network for Organ Sharing criteria or, the Nyberg criteria. An expanded criteria living donor (ECLD) was determined by fulfillment of 1 or more of 5 criteria. RESULTS Deceased and living donor kidney transplantations were performed in 228 (28.8%) and 563 (71.2%) cases, respectively. Forty-three cases (18.9%) belonged to the ECDDs. The ECDD group showed a lower posttransplantation 1-year estimated glomerular filtration rate (eGFR) than that of the standard criteria deceased donor (SCDD) group (70.7 ± 19.2 vs 48.6 ± 11.5; P < .001). The ECDDs were allocated to older recipients or recipients with more HLA mismatches than SCDDs. The number of ECLD cases was 173 (30.7%). The proportions of each medical abnormality of living donors were as follows: age older than 60 years (0.5%), hypertension (2.5%), obesity (2.1%), low eGFR (25.9%), proteinuria (0%), and microscopic hematuria (1.4%). The ECLD group showed a lower posttransplantation 1-year eGFR than that of the standard criteria living donor (SCLD) group (66.9 ± 16.0 vs 58.3 ± 11.2; P < .001). Graft survival was not different among the donor types (P = .518). CONCLUSIONS eCDs were 27.3% of the total kidney donors. Posttransplantation 1-year eGFR was lower in the ECD group. However, there was no difference in the graft survival among the different donor types.

Guggulsterone attenuates activation and survival of hepatic stellate cell by inhibiting nuclear factor kappa B activation and inducing apoptosis

Liver fibrosis is associated with the deposition of the extracellular matrix, and hepatic stellate cells (HSCs) are the major source of these matrix proteins. Guggulsterone has recently been shown to induce apoptosis in several cell lines. Thus, the aim of this study was to evaluate whether guggulsterone has antifibrotic activities by reducing the activation and survival of HSCs.

The Influence of Metabolic Factors for Nonalcoholic Fatty Liver Disease in Women

Background/Aims. Women after menopause have increased insulin resistance and visceral fat, which may increase the prevalence of nonalcoholic fatty liver disease (NAFLD). However, the pathogenesis of NAFLD in women has not been clearly defined. In this study, we aimed to determine the risk factors for NAFLD in women. Methods. A retrospective cohort study was conducted. Women who underwent abdominal ultrasonography and blood sampling for routine health check-ups were recruited. Results. Among 1,423 subjects, 695 women (48.9%) were in a menopausal state. The prevalence of NAFLD was higher in postmenopausal women than in premenopausal women (27.2% versus 14.4%, P < 0.001). In premenopausal women, low HDL-cholesterol, central obesity, and homeostasis model assessment-estimated insulin resistance showed a significant association with the increased risk of NAFLD in multivariate analysis. In postmenopausal women, the presence of diabetes, triglyceridemia, and central obesity showed a significant association with the risk of NAFLD. The presence of menopause and hormone replacement therapy in postmenopausal women were not risk factors for NAFLD. Conclusions. Our findings showed different metabolic factors for NAFLD in pre- and postmenopausal women. However, the key issues are the same: central obesity and insulin resistance. These results reemphasize the importance of metabolic factors irrespective of menopausal status in the pathogenesis of NAFLD in women.