Yoshiyuki Yamagishi

Evaluation of liver fibrosis by transient elastography using acoustic radiation force impulse: comparison with Fibroscan ®

BackgroundAccurate evaluation of liver fibrosis in patients with chronic liver damage is required to determine the appropriate treatment. Various approaches, including laboratory tests and transient elastography, have been used to evaluate liver fibrosis. Recently, transient elastography with acoustic radiation force impulse (ARFI) has been developed and applied with conventional ultrasonography. The aim of this study was to evaluate the clinical utility of transient elastography with ARFI and to compare the results with this method and those of the Fibroscan® procedure.MethodsOne hundred and thirty-one patients with liver damage, who underwent liver biopsy at our department, were enrolled prospectively in this study. Elastography with ARFI (applied with ACUSON S2000®), and Fibroscan® was performed at the same time as liver biopsy. These measurements were compared with histological findings in liver biopsy specimens, and measurement accuracy was evaluated by receiver-operating characteristic analysis.ResultsElastography values with both procedures were significantly correlated with the stages of liver fibrosis and there was little difference in the results obtained using the 2 procedures. The accuracy of differential diagnosis between no fibrosis at F0 and more than F1 stage was insufficient with ARFI, but this procedure was sufficient for diagnosing advanced fibrosis. The accuracy of ARFI was almost equivalent to that of the Fibroscan® method. Moreover, both ARFI and Fibroscan® values increased in proportion to the severity of hepatic inflammation when fibrosis stage is low, but not in proportion to the severity of steatosis.ConclusionsTransient elastography with ARFI is simple, non-invasive and useful for diagnosing the stage of fibrosis in chronic liver disease. The utility of ARFI was almost equivalent to that of the Fibroscan® method.

Etiology and prognosis of fulminant hepatitis and late-onset hepatic failure in Japan : Summary of the annual nationwide survey between 2004 and 2009

To summarize the annual nationwide survey on fulminant hepatitis (FH) and late‐onset hepatic failure (LOHF) between 2004 and 2009 in Japan.

Diagnostic criteria of acute liver failure: A report by the Intractable Hepato-Biliary Diseases Study Group of Japan

The diagnostic criteria of fulminant hepatitis in Japan are different from those of acute liver failure in Europe and the United States, both in regard to the histological features in the liver and the cutoff values of the prothrombin time. Thus, the Intractable Hepato‐Biliary Disease Study Group established novel diagnostic criteria for “acute liver failure” in Japan based on the demographic and clinical features of the patients. Patients showing prothrombin time values of 40% or less of the standardized values or international normalized ratios of 1.5 or more caused by severe liver damage within 8 weeks of onset of the symptoms are diagnosed as having “acute liver failure”, where the liver function prior to the current onset of liver damage is estimated to be normal. Acute liver failure is classified into “acute liver failure without hepatic coma” and “acute liver failure with hepatic coma,” depending on the severity of the hepatic encephalopathy; the latter is further classified into two types, the “acute type” and the “subacute type”, in which grade II or more severe hepatic coma develops within 10 days and between 11 and 56 days, respectively, after the onset of disease symptoms. Patients without histological findings of hepatitis, such as those with liver damage caused by drug toxicity, circulatory disturbance or metabolic disease, are also included in the disease entity of “acute liver failure”, while acute‐on‐chronic liver injuries, such as liver injury caused by alcohol, are excluded. A nationwide survey of “acute liver failure” in Japan based on the novel criteria is proposed.

CCL2-induced migration and SOCS3-mediated activation of macrophages are involved in cerulein-induced pancreatitis in mice

BACKGROUND & AIMS Acute pancreatitis is a common inflammatory disease mediated by damage to acinar cells and subsequent pancreatic inflammation with recruitment of leukocytes. We investigated the pathologic roles of innate immune cells, especially macrophages, in cerulein- and L-arginine-induced acute pancreatitis in mice. METHODS Acute pancreatitis was induced by sequential peritoneal administration of cerulein to mice. We determined serum concentrations of amylase and lipase, pancreatic pathology, and features of infiltrating mononuclear cells. We performed parabiosis surgery to assess the hemodynamics of pancreatic macrophages. RESULTS Almost all types of immune cells, except for CD11b(high)CD11c(-) cells, were detected in the pancreas of healthy mice. However, activated CD11b(high)CD11c(-) cells, including Gr-1(low) macrophages and Gr-1(high) cells (granulocytes and myeloid-derived suppressor cells), were detected in damaged pancreas after cerulein administration. CCL2(-/-) mice given cerulein injections developed significantly less severe pancreatitis, with less infiltration of CD11b(high)CD11c(-)Gr-1(low) macrophages, but comparable infiltration of myeloid-derived suppressor cells, compared with cerulein-injected wild-type mice. Parabiosis and bone marrow analyses of these mice revealed that the CD11b(high)CD11c(-)Gr-1(low) macrophages had moved out of the bone marrow. Furthermore, mice with macrophage-specific deletion of suppressor of cytokine signaling 3 given injections of cerulein developed less severe pancreatitis and Gr-1(low) macrophage produced less tumor necrosis factor-α than wild-type mice given cerulein, although the absolute number of CD11b(high)CD11c(-)Gr-1(low) macrophages was comparable between strains. Induction of acute pancreatitis by L-arginine required induction of macrophage migration by CCL2, via the receptor CCR2. CONCLUSIONS Cerulein induction of pancreatitis in mice involves migration of CD11b(high)CD11c(-)Gr-1(low) macrophage from the bone marrow (mediated by CCL2 via CCR2) and suppressor of cytokine signaling 3-dependent activation of macrophage. These findings might lead to new therapeutic strategies for acute pancreatitis.

Treatment of hepatitis C virus with peg-interferon and ribavirin combination therapy significantly affects lipid metabolism.

Aim:  We investigated lipid metabolism in patients with chronic hepatitis C virus (HCV), serotype 1, undergoing combination therapy with PEG‐IFN α‐2b (PEG‐IFN) and ribavirin (RBV).

Value of computed tomography-derived estimated liver volume/standard liver volume ratio for predicting the prognosis of adult fulminant hepatic failure in Japan

Background and Aims:  The prognosis of fulminant hepatic failure (FHF) has been improved but is still unsatisfactory, and liver atrophy has been reported as a poor prognostic factor for this disease. The aim of this study was to assess the clinical value of the estimated liver volume (ELV) compared to the standard liver volume (SLV) in patients with FHF.

MyD88-dependent pathway accelerates the liver damage of Concanavalin A-induced hepatitis

We have explored the pathological role of the MyD88 signaling pathway via Toll-like receptors (TLRs) that mediate the recognition of pathogen-associated molecular patterns (PAMPs) in a murine model of autoimmune hepatitis induced by administering Concanavalin A (ConA). We first found that various TLRs and MyD88 molecules were expressed in liver of Con A-treated and untreated wild-type (WT) mice including liver macrophages. Flowcytometric analysis revealed that liver CD11b(+)CD11c(-) and CD11b(+)CD11c(+) antigen-presenting cells express TLR2, although NK and NKT cells did not. When WT and MyD88(-/-) mice were intravenously administered with Con A, the severity of hepatitis was significantly lower in Con A-injected MyD88(-/-) mice than in WT mice in terms of the histopathology, the levels of serum transaminase and pro-inflammatory cytokines (TNF-alpha, IFN-gamma, and IL-6), and upregulation of CD80/CD86 and TNF-alpha on/in liver macrophages. The results provide evidence of a possible contribution of the TLRs-MyD88 signaling pathway in activating TLR-expressing liver macrophages in the autoimmune hepatitis model, and thus indicate that the strategy of blockade of pathological pathogens via the intestinal lumen may be feasible for the treatment of the disease.

Low-dose ethanol attenuates gut ischemia/reperfusion-induced liver injury in rats via nitric oxide production

Background and Aims:  The acute administration of low‐dose ethanol was demonstrated to attenuate liver injury elicited by gut ischemia/reperfusion (I/R). Nitric oxide (NO) has been found to be a modulator of adhesive interactions between leukocytes, platelets, and endothelial cells, but there has been much controversy about the effects of ethanol on NO regulation. The objective of this study was to investigate the role of NO in ethanol‐reduced hepatic microvascular dysfunction elicited by gut I/R.

Classification of the etiologies of acute liver failure in Japan: A report by the Intractable Hepato-Biliary Diseases Study Group of Japan

The Intractable Liver Diseases Study Group of Japan, supported by the Ministry of Health, Labor and Welfare, established novel diagnostic criteria for “acute liver failure” in 2011. In these criteria, patients without histological findings of hepatitis are included in the disease entity of “acute liver failure”, as in Europe and the USA. In this report, classification criteria for the etiologies of “acute liver failure” in Japan are proposed.

Prominent Steatosis with Hypermetabolism of the Cell Line Permissive for Years of Infection with Hepatitis C Virus

Most of experiments for HCV infection have been done using lytic infection systems, in which HCV-infected cells inevitably die. Here, to elucidate metabolic alteration in HCV-infected cells in a more stable condition, we established an HCV-persistently-infected cell line, designated as HPI cells. This cell line has displayed prominent steatosis and supported HCV infection for more than 2 years, which is the longest ever reported. It enabled us to analyze metabolism in the HCV-infected cells integrally combining metabolomics and expression arrays. It revealed that rate-limiting enzymes for biosynthesis of cholesterol and fatty acids were up-regulated with actual increase in cholesterol, desmosterol (cholesterol precursor) and pool of fatty acids. Notably, the pentose phosphate pathway was facilitated with marked up-regulation of glucose-6-phosphate dehydrogenase, a rete-limiting enzyme, with actual increase in NADPH. In its downstream, enzymes for purine synthesis were also up-regulated resulting in increase of purine. Contrary to common cancers, the TCA cycle was preferentially facilitated comparing to glycolysis pathway with a marked increase of most of amino acids. Interestingly, some genes controlled by nuclear factor (erythroid-derived 2)-like 2 (Nrf2), a master regulator of antioxidation and metabolism, were constitutively up-regulated in HPI cells. Knockdown of Nrf2 markedly reduced steatosis and HCV infection, indicating that Nrf2 and its target genes play important roles in metabolic alteration and HCV infection. In conclusion, HPI cell is a bona fide HCV-persistently-infected cell line supporting HCV infection for years. This cell line sustained prominent steatosis in a hypermetabolic status producing various metabolites. Therefore, HPI cell is a potent research tool not only for persistent HCV infection but also for liver metabolism, overcoming drawbacks of the lytic infection systems.