Byung Min Ahn

MRP2 haplotypes confer differential susceptibility to toxic liver injury

Objectives Multidrug resistance protein 2 (MRP2, ABCC2) plays an important role in the biliary clearance of a wide variety of endogenous and exogenous toxic compounds. Therefore, polymorphisms and mutations in the MRP2 gene may affect individual susceptibility to hepatotoxic reactions. Methods Associations between genetic variations of MRP2 and toxic hepatitis were investigated using integrated population genetic analysis and functional molecular studies. Results Using a gene scanning method, 12 polymorphisms and mutations were found in the MRP2 gene in a Korean population. Individual variation at these sites was analyzed by conventional DNA screening in 110 control subjects and 94 patients with toxic hepatitis induced mostly by herbal remedies. When haplotypes were identified, over 85% of haploid genes belonged to the five most common haplotypes. Among these, a haplotype containing the g.−1774delG polymorphism showed a strong association with cholestatic or mixed-type hepatitis, and a haplotype containing the g.−1549G>A, g.−24C>T, c.334−49C>T, and c.3972C>T variations was associated with hepatocellular-type hepatitis. A comprehensive functional study of these sites revealed that genetic variations in the promoter of this gene are primarily responsible for the susceptibility to toxic liver injuries. The g.−1774delG variation and the combined variation of g.−1549G>A and g.−24C>T decreased MRP2 promoter activity by 36 and 39%, respectively. In addition, the promoter carrying the g.−1774delG allele showed a defect in the bile acid-induced induction of promoter activity. Conclusions These results suggest that genetic variations of MRP2 are an important predisposing factor for herbal-induced or drug-induced toxic liver injuries.

A prospective nationwide study of drug-induced liver injury in Korea.

OBJECTIVES:To address a growing concern about drug-induced liver injury (DILI), a nationwide study was performed to investigate the significance of DILI in Korea.METHODS:From May 2005 to May 2007, cases of DILI (alanine transferase >3 × upper normal limit or total bilirubin >2 × upper normal limit) from 17 referral university hospitals were prospectively enrolled. Adjudication by the seven review boards was considered for the confirmation of causality and the Roussel Uclaf Causality Assessment Method (RUCAM) scale was used.RESULTS:A total of 371 cases were diagnosed with DILI. The extrapolated incidence of hospitalization at university hospital in Korea was 12/100,000 persons/year. The causes included “herbal medications” (102, 27.5%), “prescription or non-prescription medications” (101, 27.3%), “health foods or dietary supplements” (51, 13.7%), “medicinal herbs or plants” (35, 9.4%), “folk remedies” (32, 8.6%), “combined” (30, 8.2%), “herbal preparations” (12, 3.2%), and others (8, 2.2%). Nine cases were linked to acetaminophen. The frequencies of hepatocellular, mixed, and cholestatic types were 76.3, 14.8, and 8.9%, respectively. A total of 234 cases met the criteria for Hys law. Five patients died or underwent transplantation. Twenty-five cases (21 herbs and 4 medications) did not meet the time-to-onset criteria of the RUCAM.CONCLUSIONS:DILI appears to be a highly relevant health problem in Korea. “Herbal medications” are the principal cause of DILI. A more objective and reproducible causality assessment tool is strongly desired as the RUCAM scale frequently undercounts the cases caused by herbs owing to a lack of previous information and incompatible time criteria.

A case of acute cholestatic hepatitis associated with the seeds of Psoralea corylifolia (Boh-Gol-Zhee).

The potential hepatotoxicity of herbal remedies is usually ignored in daily life. One such compound, Boh-Gol-Zhee (in Chinese, Bu Ku Zi), appeared to be associated with the occurrence of acute cholestatic hepatic injury in the following case. Some alternative medicine therapists claim that Psoralea corylifolia is effective for the treatment of osteoporosis. We observed a case of acute cholestatic hepatitis associated with the use of the seeds of Psoralea corylifolia in amounts over 10 times the usual dose in a postmenopausal woman. Liver biopsy showed zone three necroses, degenerating cells, cholestasis, and infiltrations with inflammatory cells. This case stresses the need to warn of the potential hepatotoxicity of the seed of Psoralea corylifolia, especially in a large dose.

Elevation of serum asialo-α1 acid glycoprotein concentration in patients with hepatic cirrhosis and hepatocellular carcinoma as measured by antibody-lectin sandwich assay

Serum asialoglycoproteins (desialylated glycoproteins) concentration was reported to be elevated in patients with hepatic disease as compared with that of normal subjects. In this study, we measured serum asialo-alpha(1) acid glycoprotein (AsAGP) level by a solid-phase sandwich assay in which monoclonal antibody (mAb) to alpha(1)-acid glycoprotein and galactose-binding lectin, ricinus communis (RCA), have been employed as capture protein and probe protein, respectively. The mAb-RCA sandwich assay was sensitive (0.02 μg/ml) and specific for AsAGP. We have determined AsAGP concentration of 869 serum specimens and analyzed the results using l.38 and 2.24 μg/ml (AsAGP) as cut-off values, respectively. AsAGP level was 0.80+/-0.29 μg/ml (mean+/-S.D.) with 97 normal serum specimens and elevated primarily in patients with liver cirrhosis (LC) or hepatocellular carcinoma (HCC). Using 1.38 μg/ml as a cutoff, 4/97 normal subjects, 11/39 acute hepatitis and 26/159 non-hepatic disease exhibited a slight elevation, whereas, AsAGP level was significantly elevated in 182/230 LC and 63/72 HCC. Meanwhile, a cutoff of 2.24 μg/ml allowed significant differentiation of LC or HCC from chronic hepatitis. Serum AsAGP level appeared to increase progressively with increasing severity of liver disease in cirrhotic patients. Thus, serum AsAGP concentration, as measured by the new mAb-RCA sandwich assay, may be a useful differential marker as a diagnostic aid for LC or HCC.

A Case of Pancreatic Endometrial Cyst

Pancreatic endometrial cyst is an extremely rare instance of ectopic endometriosis that was first described by Marchevsky in 19841). A 21-yr-old woman with a history of epigastric pain and weight loss was found to have a cystic lesion in the pancreas on CT-scan. Under the tentative diagnosis of a pancreatic cystic neoplasm, partial pancreatectomy was performed. Histopathological examination of the specimen revealed cystic endometriosis. The clinicopathological features of the lesion are discussed and literature concerning this extremely rare lesion is reviewed.

Microsatellite instability and mutations of E2F-4 in hepatocellular carcinoma from Korea

It has been suggested that genetic changes in cancers are related to genomic instability. To evaluate a possible correlation between growth-regulatory genes and genomic instability in HCC, we investigated microsatellite instability and mutations of TGF-beta type II receptor (TGF-beta RII) and E2F-4 genes in each pair of tumor and surrounding nontumor liver tissues, collected from 19 patients with HCC. By the identification of mutations in six different genetic loci (D1S170, D2S123, D4S395, D13S126, D13S260, and D16S402), one or more alterations in microsatellite markers were identified in 13/19 (68%) hepatocellular carcinoma specimens. When two repeated sequences of TGF-beta RII gene, poly(A)(10) tract in exon 8 and poly(GT)(3) tract in exon 9, were analyzed by polymerase chain reaction-single strand conformational polymorphism, none of the 19 hepatocellular carcinoma specimens showed mutations. When amplicons of poly(AGC)(13) tract of E2F-4 were analyzed by cloning and automated sequencing, 5/19 (36%) hepatocellular carcinomas showed deletion mutation in one or two AGC repeats and such mutations were identified only among cases with microsatellite instability. These results suggest that both microsatellite instability and mutations of E2F-4 occur commonly in hepatocellular carcinoma and play an important role in hepatocarcinogenesis.

Anxiety and depression propensities in patients with acute toxic liver injury

AIM To investigate anxiety and depression propensities in patients with toxic liver injury. METHODS The subjects were divided into three groups: a healthy control group (Group 1, n = 125), an acute non-toxic liver injury group (Group 2, n = 124), and a group with acute toxic liver injury group caused by non-commercial herbal preparations (Group 3, n = 126). These three groups were compared and evaluated through questionnaire surveys and using the Hospital Anxiety-Depression Scale (HADS), Beck Anxiety Inventory (BAI), Beck Depression Inventory (BDI), and the hypochondriasis scale. RESULTS The HADS anxiety subscale was 4.9 ± 2.7, 5.0 ± 3.0 and 5.6 ± 3.4, in Groups 1, 2, and 3, respectively. The HADS depression subscale in Group 3 showed the most significant score (5.2 ± 3.2, 6.4 ± 3.4 and 7.2 ± 3.4 in Groups 1, 2, and 3, respectively) (P < 0.01 vs Group 1, P < 0.05 vs Group 2). The BAI and BDI in Group 3 showed the most significant score (7.0 ± 6.3 and 6.9 ± 6.9, 9.5 ± 8.6 and 8.8 ± 7.3, 10.7 ± 7.2 and 11.6 ± 8.5 in Groups 1, 2, and 3, respectively) (BAI: P < 0.01 vs Group 1, P < 0.05 vs Group 2) (BDI: P < 0.01 vs Group 1 and 2). Group 3 showed a significantly higher hypochondriasis score (8.2 ± 6.0, 11.6 ± 7.5 and 13.1 ± 6.5 in Groups 1, 2, and 3, respectively) (P < 0.01 vs Group 1, P < 0.05 vs Group 2). CONCLUSION Psychological factors that present vulnerability to the temptation to use alternative medicines, such as herbs and plant preparations, are important for understanding toxic liver injury.

Ultrastructural Changes of Hepatic Stellate Cells in the Space of Disse in Alcoholic Fatty Liver

Background : Hepatic stellate cell (HSC) has been suggested to play a role in fibrogenesis in alcoholic liver disease. We evaluate the correlation with fibrogenesis and ultrastructure of hepatic stellate cells in alcoholic fatty liver. Methods : We studied 6 patients with alcoholic fatty liver and 5 non-alcoholic fatty liver. The numbers of fat droplets in hepatic stellate cell was determined by electron microscopy. We also studied the grading of deposition of collagen fibers in the space of Disse. We were to evaluate the structure of hepatic stellate cells in the space of Disse by light and electron microscopy. Results : Wider distribution of fat droplets in hepatic stellate cells in alcoholic fatty liver than in normal liver. The hypertrophied endoplasmic reticulum in hepatic stellate cells is a prominent findings in alcoholic fatty liver. We observed basement membrane-like materials in patients with alcoholic fatty liver with hepatic fibrosis. Conclusion : The results demonstrate that, in patients with alcoholic fatty liver by alcoholic liver injury, the hepatic stellate cells may play an important role in the fibrogenesis of perisinusoidal spaces in the liver.

The Relationship between Virological Characteristics of Hepatitis C Virus (HCV) and Reactivity to the Regional Specific Proteins of HCV

Background Although the polyproteins of hepatitis C virus(HCV) are processed and formed in nearly equimolar amounts, individual functional proteins have a discrepancy in their time of appearance following HCV infection and eliciting immune response. This study was conducted to compare the reactivity toward regional specific HCV protein in relation to virological characteristics, including HCV genotype and HCV replication. Methods Sera from forty-five patients with chronic HCV infection were analyzed through the experiments of the recombinant immunoblot assay(RIBA-2), HCV genotyping and HCV RNA quantitation. Results The frequencies of seropositivity to C22-3, C33C, C100-3 and 5-1-1 proteins were 91.1%, 91.1%, 64.4% and 53.3%, respectively, of all the patients, and thus the antibodies to C22-3 and C33C proteins were found more frequently (p <0.05). The antibody responses between core or NS3 proteins and NS4 proteins showed more discrepancy in the HCC group than that in the CH group, implying a possibility of oncogenic potential of core or NS3 gene in hepatocarcinogenesis. The detection rate of antibodies to C22-3 and C33C, in accordance with serum HCV RNA levels, was significantly higher in highly viremic patients than that in low viremic patients (p <0.05). Antibodies to C22-3, C33C, C100-3 and 5-1-1 were also found more frequently in patients with HCV genotype 1b, compared to those with HCV genotype 2a (p <0.05). Conclusion These results suggest that antibody detection of HCV may depend on the virological characteristics of HCV, the levels of HCV replication and HCV genotype and, therefore, HCV RNA detection using RT-PCR technique is essential for confirmatory diagnosis for HCV infection. Furthermore, the HCV core or NS3 Protein may play important role in hepatocarcinogenesis.

PCNA Expression and Electron Microscopic Study of Acinus-Forming Hepatocytes in Chronic Hepatitis B

Background One of the major morphologic characteristics of hepatitis B is a hepatocellular regeneration which is induced by massive hepatocyte necrosis and associated with proliferative activity of hepatocytes. The purpose of this study is to document the proliferative activity of hepatocytes in various types of hepatitis B by immunohistochemical staining for proliferative cell nuclear antigen-labelling index (PCNA-LI) and electron microscopy. Methods We studied 83 patients with hepatitis B; 11 cases of acute viral hepatitis, 24 cases of mild chronic hepatitis, 34 cases of severe chronic hepatitis with early cirrhosis and 14 cases of severe chronic hepatitis. The PCNA was tested by immunohistochemical staining using anti-PCNA antibody. Furthermore we evaluated the ultrastructure of acinus-forming hepatocytes (AFH) by electron microscopy. Results The expression rate and labelling index of PCNA were 27.3% and 5.3±0.9% in acute viral hepatitis, 62.5% and 22.9±31.7% in mild chronic hepatits, and then 47.1% and 14.7±24.2% in severe chronic hepatitis with early cirrhosis, respectively (Figure 1). By contrast, no detectable PCNA expression was noted in AFH. Electron microscopic findings showed that hepatocytes forming a rosette underwent marked degenerative changes with sinusoidal capillarization and increased fine strands of collagen fiber in portal area. Conclusion The proliferative acitivity of hepatitis B was significantly decreased in severe chronic hepatitis containing AFH. This result suggested that differences in proliferative activity was associated with hepatic cell necrosis and AFH.