Yoshikazu Murawaki

Genome-wide association of IL28B with response to pegylated interferon-α and ribavirin therapy for chronic hepatitis C

The recommended treatment for patients with chronic hepatitis C, pegylated interferon-α (PEG-IFN-α) plus ribavirin (RBV), does not provide sustained virologic response (SVR) in all patients. We report a genome-wide association study (GWAS) to null virological response (NVR) in the treatment of patients with hepatitis C virus (HCV) genotype 1 within a Japanese population. We found two SNPs near the gene IL28B on chromosome 19 to be strongly associated with NVR (rs12980275, P = 1.93 × 10−13, and rs8099917, 3.11 × 10−15). We replicated these associations in an independent cohort (combined P values, 2.84 × 10−27 (OR = 17.7; 95% CI = 10.0–31.3) and 2.68 × 10−32 (OR = 27.1; 95% CI = 14.6–50.3), respectively). Compared to NVR, these SNPs were also associated with SVR (rs12980275, P = 3.99 × 10−24, and rs8099917, P = 1.11 × 10−27). In further fine mapping of the region, seven SNPs (rs8105790, rs11881222, rs8103142, rs28416813, rs4803219, rs8099917 and rs7248668) located in the IL28B region showed the most significant associations (P = 5.52 × 10−28–2.68 × 10−32; OR = 22.3–27.1). Real-time quantitative PCR assays in peripheral blood mononuclear cells showed lower IL28B expression levels in individuals carrying the minor alleles (P = 0.015).

FibroIndex, a practical index for predicting significant fibrosis in patients with chronic hepatitis C

Diagnosis of the stage of liver fibrosis in chronic hepatitis C is essential for making a prognosis and deciding on antiviral therapy. In the present study a simple model consisting of routine laboratory tests was constructed and then validated in cross‐sectional and longitudinal investigations. Consecutive treatment‐naive patients with chronic hepatitis C who had undergone liver biopsy were divided into 2 cohorts: an estimation set (n = 240) and a validation set (n = 120). A longitudinal set consisted of 30 patients who had undergone a liver biopsy twice, before and after IFN treatment. The FibroIndex was derived from the platelet count, AST, and gamma globulin measurements in the estimation set. The areas under the ROC curves of the FibroIndex for predicting significant fibrosis were 0.83 and 0.82 for the validation set, better than those of the Forns index and the aminotransferase‐to‐platelet ratio index (APRI). Using the best cutoff values, whether significant fibrosis was present was diagnosed with high positive predictive values, and 35% of patients could avoid liver biopsy. In the longitudinal set, there was a significant decrease in the FibroIndex of 14 patients whose fibrosis stage improved, and a significant increase in that of 5 patients whose fibrosis stage deteriorated. Change in the FibroIndex correlated significantly with variation in fibrosis stage. There was no such correlation with the Forns index or the APRI. Conclusion: The FibroIndex is a simple and reliable index for predicting significant fibrosis in chronic hepatitis C and could also be used as a surrogate marker during antifibrotic treatment for chronic hepatitis C. (HEPATOLOGY 2007;45:297–306.)

Influence of genotypes and precore mutations on fulminant or chronic outcome of acute hepatitis B virus infection.

The outcome of acute hepatitis B virus (HBV) infection is variable, influenced by host and viral factors. From 1982 through 2004, 301 patients with acute HBV infection entered a multi‐center cross‐sectional study in Japan. Patients with fulminant hepatitis (n = 40) were older (44.7 ± 16.3 vs. 36.0 ± 14.3 years, P < .0017), less predominantly male (43% vs. 71%, P = .0005), less positive for hepatitis B e antigen (HBeAg) (23% vs. 60%, P < .0001), less infected with subgenotype Ae (0% vs. 13%, P < .05), and more frequently with Bj (30% vs. 4%, P < .0001) than those with acute self‐limited hepatitis (n = 261). Precore (G1896A) and core‐promoter (A1762T/G1764A) mutations were more frequent in patients with fulminant than acute self‐limited hepatitis (53% vs. 9% and 50% vs. 17%, P < .0001 for both). HBV infection persisted in only three (1%) patients, and they represented 2 of the 23 infected with Ae and 1 of the 187 with the other subgenotypes (9% vs. 0.5%, P = .032); none of them received antiviral therapy. In multivariate analysis, age 34 years or older, Bj, HBeAg‐negative, total bilirubin 10.0 mg/dL or greater, and G1896A mutation were independently associated with the fulminant outcome. In in vitro transfection experiments, the replication of Bj clone was markedly enhanced by introducing either G1896A or A1762T/G1764A mutation. In conclusion, persistence of HBV was rare (1%) and associated with Ae, whereas fulminant hepatitis was frequent (13%) and associated with Bj and lack of HBeAg as well as high replication due to precore mutation in patients with acute HBV infection. (HEPATOLOGY 2006;44:326–334.)

Genome-Wide Association Study Confirming Association of HLA-DP with Protection against Chronic Hepatitis B and Viral Clearance in Japanese and Korean

Hepatitis B virus (HBV) infection can lead to serious liver diseases, including liver cirrhosis (LC) and hepatocellular carcinoma (HCC); however, about 85–90% of infected individuals become inactive carriers with sustained biochemical remission and very low risk of LC or HCC. To identify host genetic factors contributing to HBV clearance, we conducted genome-wide association studies (GWAS) and replication analysis using samples from HBV carriers and spontaneously HBV-resolved Japanese and Korean individuals. Association analysis in the Japanese and Korean data identified the HLA-DPA1 and HLA-DPB1 genes with Pmeta = 1.89×10−12 for rs3077 and Pmeta = 9.69×10−10 for rs9277542. We also found that the HLA-DPA1 and HLA-DPB1 genes were significantly associated with protective effects against chronic hepatitis B (CHB) in Japanese, Korean and other Asian populations, including Chinese and Thai individuals (Pmeta = 4.40×10−19 for rs3077 and Pmeta = 1.28×10−15 for rs9277542). These results suggest that the associations between the HLA-DP locus and the protective effects against persistent HBV infection and with clearance of HBV were replicated widely in East Asian populations; however, there are no reports of GWAS in Caucasian or African populations. Based on the GWAS in this study, there were no significant SNPs associated with HCC development. To clarify the pathogenesis of CHB and the mechanisms of HBV clearance, further studies are necessary, including functional analyses of the HLA-DP molecule.

Distribution of Hepatitis B Virus Genotypes among Patients with Chronic Infection in Japan Shifting toward an Increase of Genotype A

ABSTRACT Acute hepatitis B virus (HBV) infection has been increasing through promiscuous sexual contacts, and HBV genotype A (HBV/A) is frequent in patients with acute hepatitis B (AHB) in Japan. To compare the geographic distribution of HBV genotypes in patients with chronic hepatitis B (CHB) in Japan between 2005 and 2006 and between 2000 and 2001, with special attention to changes in the proportion of HBV/A, a cohort study was performed to survey changes in genotypes of CHB patients at 16 hospitals throughout Japan. Furthermore, we investigated the clinical characteristics of each genotype and examined the genomic characteristics of HBV/A isolates by molecular evolutionary analyses. Of the 1,271 patients, 3.5%, 14.1%, and 82.3% were infected with HBV/A, -B, and -C, respectively. In comparison with our previous survey during 2000 and 2001, HBV/A was twice as frequent (3.5% versus 1.7%; P = 0.02). The mean age was lower in the patients with HBV/A than in those with HBV/B or -C. Based on phylogenetic analyses of 11 full-length genomes and 29 pre-S2/S region sequences from patients, HBV/A isolates were imported from Europe and the United States, as well as the Philippines and India. They clustered with HBV/A from AHB patients and have spread throughout Japan. HBV/A has been increasing in CHB patients in Japan as a consequence of AHB spreading in the younger generation through promiscuous sexual contacts, aided by a tendency of HBV/A to induce chronic hepatitis. The spread of HBV/A infection in Japan should be prevented by universal vaccination programs.

Combination therapy with transcatheter arterial chemoembolization and percutaneous ethanol injection compared with percutaneous ethanol injection alone for patients with small hepatocellular carcinoma

To assess whether the effectiveness of a combination of transcatheter arterial chemoembolization (TACE) and percutaneous ethanol injection (PEI) is superior to PEI alone in the treatment of patients with small hepatocellular carcinoma (HCC), a randomized controlled study was performed.

Diagnostic value of serum type IV collagen test in comparison with platelet count for predicting the fibrotic stage in patients with chronic hepatitis C

Background and Aim: The serum type IV collagen test is now used as a diagnostic aid for the detection of liver fibrosis and cirrhosis. Recently, a platelet count has been reported to be a useful marker for assessing the fibrotic stage in chronic hepatitis C. The aim of this study was to compare the usefulness of the serum type IV collagen test and platelet count for diagnosing the fibrotic stage in chronic hepatitis C patients.

Tissue inhibitor of metalloproteinase-1 in the liver of patients with chronic liver disease.

BACKGROUND/AIMS Tissue inhibitor of metalloproteinase (TIMP)-1 is an important regulator of matrix metalloproteinase activity. To clarify the changes in TIMP-1 in diseased livers, we measured TIMP-1 concentrations in liver tissue samples from patients with chronic liver disease. The relationship between serum and liver levels of TIMP-1 was also examined in some patients. METHODS The subjects were 68 patients who underwent liver biopsy. The liver TIMP-1 concentration was measured using an enzyme immunoassay after the extraction of TIMP-1 with 2 M guanidine. RESULTS As compared with the controls (n=10), the liver TIMP-1 level was increased 2.2-fold in the 24 chronic active hepatitis 2A patients, 2.9-fold in the 10 chronic active hepatitis 2B patients and 4.1-fold in the six liver cirrhosis patients, but no significant increase was observed among the 18 chronic persistent hepatitis patients. The liver TIMP-1 levels were closely correlated with the histological degrees of periportal necrosis, portal inflammation, and liver fibrosis. When the localization of TIMP-1 was examined immunohistochemically, TIMP-1 was stained mainly in hepatocytes, and the intensity was stronger in the livers of chronic active hepatitis and liver cirrhosis patients than in those of the chronic persistent hepatitis patients. The serum TIMP-1 and liver TIMP-1 levels were significantly correlated, indicating that serum TIMP-1 could reflect the change of liver TIMP-1 in patients with chronic liver disease. CONCLUSION Liver TIMP-1 concentration increases with progression of the liver disease, when the degradation of extracellular matrix proteins is decreased, resulting in the development of liver fibrosis.

Diagnostic value of serum markers of connective tissue turnover for predicting histological staging and grading in patients with chronic hepatitis C.

Purpose. Chronic hepatitis C is an insidiously progressive disease, in which repeated assessment of liver histology is required. Various serum fibrotic markers have now been introduced. Our present aim was to assess, by receiver operating characteristic analysis, the usefulness of serum fibrotic markers for diagnosing fibrotic staging and necroinflammatory grading in chronic hepatitis C. Methods. Serum levels of procollagen type III N-terminal peptide (PIIINP), 7S fragment of type IV collagen (PIVNP), hyaluronan (HA), matrix metalloproteinase (MMP)-1, MMP-2, and tissue inhibitor of metalloproteinases (TIMP)-1 were measured in 169 patients with chronic hepatitis C. Results. The accuracy of these tests for discriminating stages greater than F2 from stages less than F1 was superior to that for discriminating stage F3 from stages less than F2. The most useful test for predicting stages greater than F2 was the serum HA test (cutoff value, 50 ng/ml; sensitivity, 75%; specificity, 80%), and the next-most useful was the serum MMP-2 test (cutoff value, 550 ng/ml; sensitivity, 75%; specificity, 70%). The usefulness of these tests for discriminating moderate grade from grades less than mild was superior to that for discriminating grades more than mild from minimal grade. The most useful test for predicting moderate grade was the serum HA test (cutoff value, 60 ng/ml; sensitivity, 77%; specificity, 74%), and the second-most useful was the serum PIVNP test (cutoff value, 6.5 ng/ml; sensitivity, 74%; specificity, 75%). The combination of the most useful and next-most useful test results increased the accuracy of the diagnosis of staging and grading. Conclusions. These serum fibrotic markers, especially the serum HA test, would be clinically useful for assessing staging and grading in patients with chronic hepatitis C.

Clinical significance of serum hyaluronan in patients with chronic viral liver disease

In order to elucidate the clinical significance of serum hyaluronan in chronic viral hepatitis, serum hyaluronan concentrations were measured using a sandwich enzyme binding assay in 115 patients with chronic viral hepatitis. These findings were examined in relation to the results of laboratory liver tests, levels of serum markers for fibrosis and liver histological findings. Serum hyaluronan levels increased with the progress of liver disease, particularly in liver cirrhosis. There were no significant differences in serum hyaluronan levels among the cirrhotic patients according to Childs grade. Multivariate analysis showed that the significant independent predictors of serum hyaluronan were serum aspartate aminotransferase (P= 0.020), serum alanine aminotransferase (P= 0.008), serum cholinesterase (P< 0.001), particularly serum type IV collagen 7S domain (P< 0.0001), and the histological degree of liver fibrosis (P< 0.0001). These findings suggest that elevated serum hyaluronan levels are closely related to the severity of liver fibrosis. We assessed the predictive value of serum hyaluronan in differentiating cirrhosis from chronic hepatitis, constructing receiver operating curves; we found that serum hyaluronan was a better test for diagnosing cirrhosis than serum type IV collagen 7S domain and laboratory liver tests.