Necessity for Reassessment of Patients with Serogroup 2 Hepatitis C Virus (HCV) and Undetectable Serum HCV RNA

We encountered a patient positive for anti-hepatitis C virus (HCV) whose serum HCV RNA was undetectable with the Roche AmpliPrep/Cobas TaqMan HCV assay (CAP/CTM) version 1 but showed a high viral load with the Abbott RealTime HCV assay (ART). Discrepancies in the detectability of serum HCV RNA were investigated among 891 consecutive patients who were positive for anti-HCV. Specific nucleotide variations causing the undetectability of HCV RNA were determined and confirmed by synthesizing RNA coding those variations. Serum samples with the discrepancies were also reassessed by CAP/CTM version 2. Among the 891 anti-HCV-positive patients, 4 patients had serum HCV RNA levels that were undetectable by CAP/CTM version 1 despite having levels of > 5 log IU/ml that were detected by ART. All four patients had HCV genotype 2a and high titers of anti-HCV. Sequencing of the HCV 5' noncoding regions revealed 2 common variations, A at nucleotide (nt) 145 and T at nt 151. Synthesized RNAs of the HCV 5' noncoding region with standard (NCR145G151C) and variant nucleotides at nt 145 and nt 151 were quantified with CAP/CTM. RNAs of NCR145G151C and NCR145G151T were quantifiable with CAP/CTM version 1, while those of NCR145A151T and NCR145A151C went undetected. The substitution from G to A at nt 145 specifically conferred this undetectability, while this undetectability was reverted in synthesized HCV RNA with correction of this variation. Reassessment of these samples by CAP/CTM version 2 resulted in similar levels of HCV RNA being detected by ART. We conclude that HCV patients with undetectable HCV RNA by CAP/CTM version 1 should be reassessed for viral quantification

Newly Identified CYP2C93 Is a Functional Enzyme in Rhesus Monkey, but Not in Cynomolgus Monkey

Cynomolgus monkey and rhesus monkey are used in drug metabolism studies due to their evolutionary closeness and physiological resemblance to human. In cynomolgus monkey, we previously identified cytochrome P450 (P450 or CYP) 2C76 that does not have a human ortholog and is partly responsible for species differences in drug metabolism between cynomolgus monkey and human. In this study, we report characterization of CYP2C93 cDNA newly identified in cynomolgus monkey and rhesus monkey. The CYP2C93 cDNA contained an open reading frame of 490 amino acids approximately 84–86% identical to human CYP2Cs. CYP2C93 was located in the genomic region, which corresponded to the intergenic region in the human genome, indicating that CYP2C93 does not correspond to any human genes. CYP2C93 mRNA was expressed predominantly in the liver among 10 tissues analyzed. The CYP2C93 proteins heterologously expressed in Escherichia coli metabolized human CYP2C substrates, diclofenac, flurbiprofen, paclitaxel, S-mephenytoin, and tolbutamide. In addition to a normal transcript (SV1), an aberrantly spliced transcript (SV2) lacking exon 2 was identified, which did not give rise to a functional protein due to frameshift and a premature termination codon. Mini gene assay revealed that the genetic variant IVS2-1G>T at the splice site of intron 1, at least partly, accounted for the exon-2 skipping; therefore, this genotype would influence CYP2C93-mediated drug metabolism. SV1 was expressed in 6 of 11 rhesus monkeys and 1 of 8 cynomolgus monkeys, but the SV1 in the cynomolgus monkey was nonfunctional due to a rare null genotype (c.102T>del). These results suggest that CYP2C93 can play roles as a drug-metabolizing enzyme in rhesus monkeys (not in cynomolgus monkeys), although its relative contribution to drug metabolism has yet to be validated

Hepatitis B virus core promoter mutations G1613A and C1653T are significantly associated with hepatocellular carcinoma in genotype C HBV-infected patients

<p>Abstract</p> <p>Background</p> <p>Hepatitis B virus (HBV) is a major cause of hepatocarcinogenesis.</p> <p>To identify mutations relevant to hepatocellular carcinoma (HCC) development, we compared the full genome sequences of HBV from the sera of patients with and without HCC.</p> <p>Methods</p> <p>We compared the full genome sequences of HBV isolates from 37 HCC patients (HCC group 1) and 38 patients without HCC (non-HCC group 1). We also investigated part of the core promoter region sequences from 40 HCC patients (HCC group 2) and 68 patients without HCC. Of the 68 patients who initially did not have HCC, 52 patients remained HCC-free during the follow-up period (non-HCC group 2), and 16 patients eventually developed HCC (pre-HCC group 2). Serum samples collected from patients were subjected to PCR, and the HBV DNA was directly sequenced.</p> <p>Results</p> <p>All patients had genotype C. A comparison of the nucleotide sequences of the HBV genome between HCC group 1 and non-HCC group 1 revealed that the prevalence of G1613A and C1653T mutations in the core promoter region was significantly higher in the HCC group. These mutations tended to occur simultaneously in HCC patients. Multivariate analysis with group 2 revealed that the presence of HCC was associated with aging and the double mutation. Future emergence of HCC was associated with aging and the presence of a single G1613A mutation.</p> <p>Conclusions</p> <p>G1613A and C1653T double mutations were frequently found in patients with HCC. A single G1613A mutation was associated with future emergence of HCC. These mutations may serve as useful markers in predicting HCC development.</p

Effectiveness of Extending Treatment Duration in Therapy with Pegylated Interferon and Ribavirin for Genotype 2 Hepatitis C Virus Infection

The effectiveness of extending treatment duration as response guided therapy was previously reported for chronic hepatitis C (CHC) genotype 1, but is still controversial for genotype 2. The present study is a retrospective cohort study to investigate the effectiveness of extending treatment duration in therapy with pegylated interferon and ribavirin for patients with CHC genotype 2 by focusing on the timing at which patients obtained undetectable HCV RNA. A total of 306 patients who obtained undetectable HCV RNA by week 24 of treatment and completed 24 weeks of treatment were enrolled. Rapid virological response (RVR) to standard therapy was achieved by 122 patients (51ｵ), and 89ｵ of them obtained sustained virological response (SVR), while 69ｵ of non-RVR patients achieved SVR. Non-RVR patients with undetectable HCV RNA at week 8, and insufficient adherence＜80ｵ pegylated interferon and ribavirin during the first 24 weeks, significantly improved their SVR rate by extended therapy. Among patients receiving extended therapy, drug adherences did not differ between SVR and non-SVR patients, indicating that extending treatment duration might compensate for insufficient antiviral effects due to insufficient drug adherences. This finding might be useful in creating a guideline for extending treatment duration for patients with CHC genotype 2

Nursing Support Increases the Efficacy of Interferon Therapy in Patients with Chronic Hepatitis C

Nursing support might help patients with chronic hepatitis C (CHC) remain in good mental and physical condition during interferon (IFN) therapy. However, the effects of nursing support have not been studied adequately in this context. This case-control study evaluated the effects of nursing support during IFN therapy. Twenty-four CHC patients who received pegylated IFN and ribavirin were enrolled. Nurses advised patients on the maintenance of their mental and physical condition at weekly visits, based on the results of written questionnaires. An additional 24 patients who received IFN therapy without nursing support and who were matched for age, sex, platelet count, viral serogroup and IFN regimen were selected with propensity score matching as controls. The patients with nursing support during IFN therapy achieved higher sustained virological responses (79%) than those without nursing support (58%). Adherence to the IFN and ribavirin regimens at 24 weeks of therapy were slightly higher in the patients with nursing support than those without it, but these differences were not statistically significant. Adherence to ribavirin after 24 weeks of therapy was significantly higher in those with nursing support than those without it (93% and 66%, p＝0.045). These results suggested that nursing support services could contribute to the virological responses of CHC patients by promoting drug-regimen adherence

Laparoscopic findings of reddish markings predict hepatocellular carcinoma in patients with hepatitis B virus-related liver disease

For patients with chronic hepatitis due to hepatitis B virus (HBV), factors predicting hepatocellular carcinoma (HCC) other than high levels of HBV-DNA and alanine aminotransferase (ALT) are needed to prevent HCC development, as many patients with chronic HBV infection fulfill these conditions. The purpose of this study was to clarify factors predictive of HCC development for those patients. The study was a systematic cohort analysis of 303 consecutive patients with hepatitis B e-antigen, receiving laparoscopic examination for assessment of liver disease. Laparoscopic, histological, and clinical characteristics were investigated as related to HCC development. HCC occurred in 27 patients during a mean follow-up of 8.0 +/- A 5.0 years, at the age of 37-72 years. Significant associations with HCC development were shown for liver cirrhosis, histological activity grade, reddish markings, and older age. Multivariate analysis revealed that HCC development was strongly associated with older age and male gender (P = 0.002 and P = 0.043, respectively). HCC occurred more frequently in patients of age a parts per thousand yen30 years even with early stage than in patients of age < 30 years (P = 0.031). Severe reddish markings, a laparoscopic finding of widespread parenchymal destruction, were highly associated with HCC development in patients of age a parts per thousand yen30 years at diagnosis (odds ratio = 1.67, P = 0.034), while histological activity grade and ALT level were not (P = 0.075 and P = 0.69, respectively). HCC development is associated with older age, male gender, and liver cirrhosis. Reddish markings, rather than histological activity or ALT level, can be useful to predict HCC for HBV patients of age a parts per thousand yen30 years

Aberrant Expression of Keratin 7 in Hepatocytes as a Predictive Marker of Rapid Progression to Hepatic Failure in Asymptomatic Primary Biliary Cirrhosis

A predictive marker of the rapid progression to hepatic failure is desired for patients with asymptomatic primary biliary cirrhosis (aPBC). We performed a systematic cohort analysis of 101 patients diagnosed as having aPBC and the rapid progression to liver failure in some, by focusing on cholestasis. Cholestasis was assessed by aberrant keratin7 (K-7) expressions in the patientsʼ hepatocytes. Intralobular expressions of K-7 were found in 9 of the 101 patients. The grades of K-7 expression were significantly associated with the levels of alanine aminotransferase, alkaline phosphatase, and total bilirubin at the time of diagnosis, but not with bile duct loss or cholestasis. Stepwise logistic regression analysis revealed that high grades of K-7 expression correlated positively with high levels of total bilirubin. During the follow-up period, 8 patients developed jaundice, and the mean period until the development of jaundice was 5.2 years. The proportional hazards models for the risk of developing jaundice identified a high grade of aberrant K-7 expression in hepatocytes as the only significant risk factor. Aberrant K-7 expression in hepatocytes can be used as an additional marker to predict rapid progression to liver failure in patients with aPBC at the time of diagnosis

The impact of patatin-like phospholipase domain-containing protein 3 polymorphism on hepatocellular carcinoma prognosis

The single nucleotide polymorphism (SNP) rs738409 in patatin-like phospholipase domain-containing protein 3 (PNPLA3) is associated with hepatic fat accumulation and disease progression in patients with non-alcoholic fatty liver disease and alcoholic liver disease (ALD). This study was conducted to determine whether PNPLA3 rs738409 SNPs affect development and prognosis of hepatocellular carcinoma (HCC) in patients with various liver diseases. We enrolled 638 consecutive Japanese patients newly diagnosed with HCC between 2001 and 2010: 72 patients with hepatitis B virus (HBV), 462 with hepatitis C virus (HCV), and 104 with non-B non-C (NBNC). NBNC patients exhibited large tumors of advanced TNM stages at HCC diagnosis, and had significantly poorer prognosis than HBV or HCV patients (P < 0.001 and < 0.001, respectively; log-rank test). The G/G genotype of PNPLA3 rs738409 SNP had significantly higher distribution in NBNC patients (P < 0.001) and was significantly associated with higher body mass index (BMI) and an increased aspartate aminotransferase to platelet ratio index. No significant differences were observed in survival with differences in PNPLA3 SNP genotypes among the patients, although ALD patients with the G/G genotype of PNPLA3 SNP and low BMI had significantly poorer survival than those with high BMI (P = 0.028). The G/G genotype of PNPLA3 rs738409 SNP was more frequently distributed, and associated with BMI and fibrosis among NBNC-HCC patients but not among HBV or HCV patients. These genotypes might affect HCC prognosis in ALD patients, but not in HBV, HCV, or NAFLD patients

Impact of Comorbid Hepatic Steatosis on Treatment of Chronic Hepatitis C in Japanese Patients and the Relationship with Genetic Polymorphism of IL28B, PNPLA3 and LDL Receptor

The impact of hepatic steatosis on interferon therapy for patients with chronic hepatitis C (CHC) has been associated with single-nucleotide polymorphisms (SNP) of IL28B, patatin-like phospholipase domain-containing protein 3 (PNPLA3), and low-density lipoprotein (LDL) receptor. Whether this holds true for Japanese patients, however, remains unresolved. The present study prospectively enrolled 226 Japanese patients with CHC, and investigated the impact of hepatic steatosis and its related SNPs, including rs8099917 of IL28B, rs738409 of PNPLA3, and rs14158 of LDL receptor, on outcomes of peg-interferon and ribavirin therapy. In multivariate logistic regression analysis, significant factors affecting the severity of hepatic steatosis were high body mass index and the minor alleles of IL28B SNP (p＝0.020 and 0.039, respectively). The risk alleles of PNPLA3 SNP also showed weak association (p＝0.059). Severe steatosis and the minor alleles of IL28B SNP were significantly associated with null or partial virological response in patients with HCV genotype 1, as were female gender, and low LDL cholesterol (p＝0.049, and ＜0.001, respectively). The SNP genotype of PNPLA3 and LDL receptor did not have a significant impact on therapeutic outcomes. With respect to the SNP sites examined, the SNP of PNPLA3 has a weak association with severe hepatic steatosis, but not with the outcome of interferon therapy

Stress relaxation arrested the mainshock rupture of the 2016 Central Tottori earthquake

地震の破壊はなぜ止まるのか? --2016年鳥取県中部地震の断層サイズを決めたもの--. 京都大学プレスリリース. 2021-08-12.After a large earthquake, many small earthquakes, called aftershocks, ensue. Additional large earthquakes typically do not occur, despite the fact that the large static stress near the edges of the fault is expected to trigger further large earthquakes at these locations. Here we analyse ~10, 000 highly accurate focal mechanism solutions of aftershocks of the 2016 Mw 6.2 Central Tottori earthquake in Japan. We determine the location of the horizontal edges of the mainshock fault relative to the aftershock hypocentres, with an accuracy of approximately 200 m. We find that aftershocks rarely occur near the horizontal edges and extensions of the fault. We propose that the mainshock rupture was arrested within areas characterised by substantial stress relaxation prior to the main earthquake. This stress relaxation along fault edges could explain why mainshocks are rarely followed by further large earthquakes