Satoru Joshita

Genome-wide Association Study Identifies TNFSF15 and POU2AF1 as Susceptibility Loci for Primary Biliary Cirrhosis in the Japanese Population

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 = 2.84xa0× 10(-14) for rs4979462, and combined OR = 1.39, p = 2.38xa0× 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 pxa0= 3.66xa0× 10(-8), 3.66xa0× 10(-9), and 3.04xa0× 10(-9), respectively) and STAT4 and NFKB1 loci showed suggestive association with PBC (combined p = 1.11xa0× 10(-6) and 1.42xa0× 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.

Pretreatment prediction of virological response to peginterferon plus ribavirin therapy in chronic hepatitis C patients using viral and host factors

The interferon sensitivity determining region (ISDR) of the hepatitis C virus (HCV) and T‐helper type 1 and type 2 (Th1/Th2) ratio were analyzed along with other host and viral factors for their ability to predict the response of patients with chronic hepatitis C to pegylated interferon alpha‐2b (Peg‐IFN) and ribavirin (RBV) combination therapy. A total of 120 chronic hepatitis C patients with genotype 1 HCV and high baseline viral loads who were to undergo combination therapy scheduled for 48 weeks were enrolled. Sustained virologic response (SVR) was achieved in 54 (45%) of the 120 patients. The pretreatment factors significantly associated with SVR by logistic regression analysis were ISDR mutant [odds ratio (OR) = 86.0, P = 0.0008], Th1/Th2 ratio ≤ 15.5 (OR = 9.6, P = 0.0021), body weight 59 kg, and neutrophil count 2,300/μL. A logistic regression model to estimate SVR before combination therapy was constructed using these four factors. Patients fell into three groups when plotted according to estimated and actual SVR rates: actual SVR rate was 91% (32/35) in the high sensitivity group, 41% (15/37) in the intermediate sensitivity group, and 15% (7/48) in the low sensitivity group. Rapid or early virological responses were seen in 80% of patients with high sensitivity and who achieved SVR but were found in only 40% of patients with intermediate or low sensitivity. Null‐ and very late virological responses were quite rare in the high sensitivity group. In conclusion, a logistic regression model that includes the sequence of ISDR of the HCV, Th1/Th2 ratio, body weight, and neutrophil count can be useful for accurately predicting actual SVR rate before combination therapy. (HEPATOLOGY 2008;48:1753‐1760.)

Super high resolution for single molecule‐sequence‐based typing of classical HLA loci at the 8‐digit level using next generation sequencers

Current human leukocyte antigen (HLA) DNA typing methods such as the sequence-based typing (SBT) and sequence-specific oligonucleotide (SSO) methods generally yield ambiguous typing results because of oligonucleotide probe design limitations or phase ambiguity for HLA allele assignment. Here we describe the development and application of the super high-resolution single-molecule sequence-based typing (SS-SBT) of HLA loci at the 8-digit level using next generation sequencing (NGS). NGS which can determine an HLA allele sequence derived from a single DNA molecule is expected to solve the phase ambiguity problem. Eight classical HLA loci-specific polymerase chain reaction (PCR) primers were designed to amplify the entire gene sequences from the enhancer-promoter region to the 3 untranslated region. Phase ambiguities of HLA-A, -B, -C, -DRB1 and -DQB1 were completely resolved and unequivocally assigned without ambiguity to single HLA alleles. Therefore, the SS-SBT method described here is a superior and effective HLA DNA typing method to efficiently detect new HLA alleles and null alleles without ambiguity.

Clinical significance of immunoglobulin G4-associated autoimmune hepatitis

BackgroundImmunoglobulin (Ig) G4-associated autoimmune hepatitis (AIH) is a recently identified and possibly new disease entity. However, the epidemiology and clinical features of IgG4-associated AIH remain uncertain. The aim of this study was to determine the prevalence and the clinical, serological, and histological characteristics of IgG4-associated AIH.MethodsWe examined the clinical features, serum IgG4 concentration, liver biopsy histology, and IgG4-bearing plasma cell infiltration of 60 patients with type 1 AIH and 22 patients with autoimmune pancreatitis.ResultsHigh serum IgG4 concentration (≥135xa0mg/dL) and IgG4-bearing plasma cell infiltration in the liver (≥10/high-power fields [HPFs]) were found in 2 of the 60 (3.3%) patients with type 1 AIH. These patients had high serum levels of IgE, giant cell change, and rosette formation in the liver. Although corticosteroid therapy reduced the serum IgG4 concentration and normalized liver enzymes and histology, one patient developed IgG4-related sclerosing cholangitis after 5xa0years of follow-up.ConclusionsBecause IgG4-associated AIH was found in over 3% of Japanese patients with type 1 AIH in our cohort, further studies are needed on this possible new disease entity and its impact on the diagnostic guidelines of AIH.

Down-regulation of SREBP-1c is associated with the development of burned-out NASH.

BACKGROUND & AIMSnIt is well-known that hepatic triglycerides (TG) diminish with the progression of non-alcoholic steatohepatitis (NASH), which has been designated as burned-out NASH, but its mechanism remains unclear. We aimed to explore the changes in hepatic fatty acid (FA) and TG metabolism with disease progression.nnnMETHODSnHepatic expression of key genes in healthy individuals (n=6) and patients with simple steatosis (SS, n=10), mild NASH (fibrosis stage 1-2, n=20), and advanced NASH (fibrosis stage 3-4, n=20) were assessed by quantitative polymerase chain reaction.nnnRESULTSnHepatic expression of genes related to FA uptake and oxidation and very-low-density lipoprotein synthesis/export did not differ among the groups. However, the mRNA levels of sterol regulatory element-binding protein (SREBP)-1c and its downstream genes FA synthase, acetyl-coenzyme A carboxylase 1, and diacylglycerol acyltransferase 1 were inversely correlated with fibrosis stage. Immunoblot analysis revealed a remarkable reduction in mature SREBP-1c levels in advanced NASH. Furthermore, hepatic expression of tumor necrosis factor-alpha increased in accordance with fibrosis progression, which was possibly related to the decrease in hepatic SREBP-1c expression.nnnCONCLUSIONSnDown-regulation of SREBP-1c and lipogenic enzymes may be associated with the development of burned-out NASH.

Serum Wisteria floribunda Agglutinin-Positive Mac-2-Binding Protein Level Predicts Liver Fibrosis and Prognosis in Primary Biliary Cirrhosis

OBJECTIVES:Noninvasive markers of liver fibrosis in patients with primary biliary cirrhosis (PBC) are needed for predicting disease progression. As the Wisteria floribunda agglutinin-positive Mac-2-binding protein (WFA+-M2BP) was recently established as a liver fibrosis glycobiomarker in chronic hepatitis C, we assessed its efficacy in evaluating liver fibrosis stage and disease progression in PBC.METHODS:A total of 137 patients with PBC who underwent liver biopsy and serological tests for WFA+-M2BP were enrolled. All patients were treated with ursodeoxycholic acid. Clinical data were compared with those for other noninvasive markers (aspartate aminotransferase-to-platelet ratio, FIB-4 index, aspartate aminotransferase/alanine aminotransferase ratio, Forn’s index, and Mayo score) for estimating liver fibrosis using receiver operating characteristic analysis. The association between WFA+-M2BP and clinical outcome (liver decompensation, liver transplantation, or death) was evaluated using the Cox proportional hazards model with stepwise method.RESULTS:WFA+-M2BP was independently associated with liver fibrosis stage as determined by liver biopsy. The cutoff values of WFA+-M2BP for fibrosis stages ≥F1, ≥F2, ≥F3, and F4 were 0.7, 1.0, 1.4, and 2.0, respectively. The area under the receiver operating characteristic curve values for significant fibrosis, severe fibrosis, and cirrhosis were 0.979, 0.933, and 0.965, respectively. WFA+-M2BP was significantly superior to the other indices for the determination of significant and severe fibrosis stages. Furthermore, the WFA+-M2BP level at enrollment was strongly and independently associated with clinical outcome (hazard ratio 18.59, P=0.021).CONCLUSIONS:Baseline measurements of WFA+-M2BP represent a simple and reliable noninvasive surrogate marker of liver fibrosis and prognosis in patients with PBC.

Long‐term outcome of Japanese patients with type 1 autoimmune hepatitis

The long‐term outcome of patients with autoimmune hepatitis (AIH) in Japan has not been well‐defined. The aim of this study was to clarify the outcome of this disease over a long follow‐up period compared with that of the general Japanese population as well as that among patients. A total of 203 AIH patients were enrolled for a mean follow‐up period of 131 months. All patients were treated with corticosteroids with or without azathioprine. The overall survival of AIH patients was similar to that of the general population in Japan. The prognosis of AIH subgroups divided according to disease severity, sex, incidence of relapse, liver histology, presence of cirrhosis, probable or definite AIH score, antibody to hepatitis B core antigen antibody positivity, or human leukocyte antigen DR4–positivity did not differ greatly among patients. However, the prognosis of patients experiencing two or more relapses was significantly poorer than that of patients with remission or a single relapse both in univariate (P < 0.001) and multivariate (P = 0.020) analyses. The development of liver malignancy was also a possibility among AIH patients with multiple relapses. Severe adverse effects of corticosteroids were rare, even in patients who underwent long‐term treatment. Conclusion: Repeated relapses of AIH are significantly associated with a poorer long‐term prognosis in Japan. AIH patients can expect a similar prognosis to that of the general population, provided they are adequately managed with continuous low doses of immunosuppressive therapy, especially after the first relapse. (HEPATOLOGY 2012)

Human leukocyte antigen class II molecules confer both susceptibility and progression in Japanese patients with primary biliary cirrhosis

Along with twin and family studies, recent genome‐wide association studies suggest that genetic factors contribute to the susceptibility and severity of primary biliary cirrhosis (PBC). Although several reports have demonstrated that the human leukocyte antigen (HLA) DRB1*08:03 allele is associated with disease susceptibility in Japan, the precise analysis of HLA haplotypes and the role of amino acid alignment have not been fully clarified. We investigated HLA class I A, B, and C and HLA class II DRB1 and DQB1 alleles and haplotypes in 229 Japanese patients with PBC and compared them with the published data of 523 healthy subjects. Significant associations were found with PBC susceptibility for the DRB1*08:03‐DQB1*06:01 (13% versus 6%; P = 0.000025; odds ratio [OR] = 2.22) and DRB1*04:05‐DQB1*04:01 haplotypes (17% versus 13%; P = 0.044; OR = 1.38). Conversely, there were significant protective associations with the DRB1*13:02‐DQB1*06:04 (2% versus 5%; P = 0.00093; OR = 0.27) and DRB1*11:01‐DQB1*03:01 haplotypes (1% versus 4%; P = 0.03; OR = 0.37). The frequency of the DRB1*09:01‐DQB1*03:03 haplotype was significantly higher in patients who had received orthotopic liver transplantation (33% versus 11%; P = 0.0012; OR = 3.96). Furthermore, the frequency of serine at position 57 (P = 0.0000015; OR = 1.83) of the DRβchain differed the most in patients with PBC, compared with healthy subjects. Conclusion: This study established the role of HLA haplotypes in determining PBC susceptibility and progression in the Japanese population. Further resequencing of the HLA region is required to more precisely identify the genetic components of PBC. (HEPATOLOGY 2012)

Serum fragmented cytokeratin 18 levels reflect the histologic activity score of nonalcoholic fatty liver disease more accurately than serum alanine aminotransferase levels.

Background and Goals Reliable noninvasive biomarkers to assess the histologic activity of nonalcoholic fatty liver disease (NAFLD) have not been established. As the frequency of Mallory bodies is known to be closely associated with the disease severity, we hypothesized that serum levels of Mallory body-related proteins were correlated with NAFLD histologic activity and evaluated this possibility. Study Serum levels of total and fragmented cytokeratin (CK) 18, heat shock protein (Hsp) 70, Hsp90α, ubiquitin+1, and p38α at the time of liver biopsy were measured in 118 NAFLD patients and their association with histologic findings and NAFLD histologic activity score (NAS) was investigated. Results Serum levels of both forms of CK18 and Hsp90α were markedly higher in patients having nonalcoholic steatohepatitis (NASH) compared with non-NASH ones. Both forms of CK18 significantly correlated with degree of steatosis, lobular inflammation, and ballooning, and showed stronger positive correlations with NAS than serum aspartate and alanine aminotransferase (AST and ALT). Multiple regression analysis further revealed that fragmented CK18 and AST were effective predictors of NAS, with the former being the more definitive of the two (P<0.001 vs. 0.005). In 20 NAFLD patients who received a follow-up biopsy, changes in fragmented CK18 levels, but not AST or ALT levels, closely paralleled those in NAS. Conclusions These results establish the usefulness of fragmented CK18 measurement for assessing and monitoring the histologic activity of NAFLD.

Association of serum cytokine levels with treatment response to pegylated interferon and ribavirin therapy in genotype 1 chronic hepatitis C patients.

BACKGROUNDnWe sought to clarify the associations among serum cytokines, amino acid substitutions in the interferon sensitivity-determining region (ISDR) and core region, and treatment outcome of pegylated interferon and ribavirin therapy in genotype 1 hepatitis C virus (HCV)-infected patients.nnnMETHODSnWe quantified a total of 8 serum cytokines before, during, and after treatment in 79 genotype 1 chronic HCV patients. Viral ISDR and core region variants were determined by direct sequencing.nnnRESULTSnHigh levels of interleukin (IL)-12 and IL-18 and more than 2 mutations in the ISDR were associated with a sustained virological response (SVR). Conversely, high baseline IL-10 levels and glutamine at amino acid 70 of the HCV core protein (Gln70) were significantly associated with a nonresponse to treatment, and patients with Gln70 had significantly higher IL-10 levels. In multivariate analysis, low IL-10, high IL-12, and high IL-18 levels were independently associated with an SVR. These 3 cytokine levels were decreased from baseline levels 4 weeks into treatment and remained low in patients with an SVR.nnnCONCLUSIONnSerum IL-10, IL-12, and IL-18 levels are predictive of the response to HCV treatment with pegylated interferon and ribavirin and are associated with amino acid substitutions in the ISDR and core region.