A possible causative role for the recently discovered hepatitis C virus (HCV) in the development of hepatocellular carcinoma (HCC) was investigated by assay of sera from HCC patients in Japan for antibodies to a recombinant HCV antigen and to hepatitis B virus (HBV) antigens. Among the 253 HCC patients examined, 156 (61.7%) had no serum markers of either a previous or a current HBV infection (group I), 46 (18.2%) were negative for HBV surface antigen but positive for anti-HBV surface and/or anti-HBV core antibody, indicating the occurrence of a previous, transient HBV infection (group II), and 51 (20.2%) were chronically infected HBV carriers as evidenced by positivity for HBV surface antigen (group Ill). The prevalence of HCV antibody in group I (68.6%) and II (58.7%) patients was significantly higher than for group m1 (3.9%) or in 148 additional patients with other (non-HCC) cancers (10.1%) (P < 0.01). Thus, there appears to be a strong association between HCV infection and the development of HCC, particularly in patients for which HBV infection cannot be implicated as a causative factor. The data also suggest an additional mode of transmission for HCV other than blood transfusion, since a history of blood transfusion was shown in only about 30% of the HCV antibodypositive HCC patients in groups I and 11. A high prevalence of HCV antibody was also shown among patients with HCC whose disease was originally thought to be due to very high ethanol consumption.The development of specific serological tests for infection by hepatitis A virus (HAV) and hepatitis B virus (HBV) has revealed that a large proportion of hepatitis cases are not caused by either ofthese agents (1-3). The resultant diagnosis of exclusion, non-A, non-B hepatitis (NANBH), now accounts for 95% of all posttransfusion hepatitis and over one-third of sporadic, acute hepatitis cases in Japan. Although symptoms in the acute phase of this disease are generally less severe than with HAV or HBV infection, NANBH is much more likely to develop into a persistent, chronic state. Over 50% of posttransfusion NANBH cases become chronically infected versus less than 10% in the case of HBV infections; typically, no chronicity results from infection by HAV. It is also clearly established that chronic NANBH can develop into hepatic cirrhosis (4-6). Accumulated serological, pathological, epidemiological, and clinical evidence suggests a significant association ofthe HBV carrier state with hepatocellular carcinoma (HCC) (7,8). In Japan, however, less than one-third ofHCC patients are also chronic HBV carriers, and the number of surgically treated HCC cases with no serological markers of prior or current HBV infection has increased steadily in Japan during the last 10 years (9). This suggests another causative factor(s). It has been hypothesized that NANBH virus(es) might be the missing causative agent in HCC development (10)(11)(12)(13)(14).The etiological agent(s) of NANBH has long been sought by many research groups (15,16), and recently a NANBH agent, ter...

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.

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General rules for recording endoscopic findings of esophageal varices were initially proposed in 1980 and revised in 1991. These rules have widely been used in Japan and other countries. Recently, portal hypertensive gastropathy has been recognized as a distinct histological and functional entity. Endoscopic ultrasonography can clearly depict vascular structures around the esophageal wall in patients with portal hypertension. Owing to progress in medicine, we have updated and slightly modified the former rules. The revised rules are simpler and more straightforward than the former rules and include newly recognized findings of portal hypertensive gastropathy and a new classification for endoscopic ultrasonographic findings.

For the identification of susceptibility loci for primary biliary cirrhosis (PBC), a genome-wide association study (GWAS) was performed in 963 Japanese individuals (487 PBC cases and 476 healthy controls) and in a subsequent replication study that included 1,402 other Japanese individuals (787 cases and 615 controls). In addition to the most significant susceptibility region, human leukocyte antigen (HLA), we identified two significant susceptibility loci, TNFSF15 (rs4979462) and POU2AF1 (rs4938534) (combined odds ratio [OR] = 1.56, p = 2.84 × 10(-14) for rs4979462, and combined OR = 1.39, p = 2.38 × 10(-8) for rs4938534). Among 21 non-HLA susceptibility loci for PBC identified in GWASs of individuals of European descent, three loci (IL7R, IKZF3, and CD80) showed significant associations (combined p = 3.66 × 10(-8), 3.66 × 10(-9), and 3.04 × 10(-9), respectively) and STAT4 and NFKB1 loci showed suggestive association with PBC (combined p = 1.11 × 10(-6) and 1.42 × 10(-7), respectively) in the Japanese population. These observations indicated the existence of ethnic differences in genetic susceptibility loci to PBC and the importance of TNF signaling and B cell differentiation for the development of PBC in individuals of European descent and Japanese individuals.