Hepatitis C virus may infect extrahepatic tissues in patients with hepatitis C

Whole blood as an alternative to plasma for detection of hepatitis C virus RNA

Peripheral blood mononuclear cells are reported to be one of the extrahepatic replication sites contributing to the persistence of hepatitis C virus (HCV) infection. Whole-blood and plasma samples from 61 individuals were compared as sources for the detection of HCV RNA. Forty-four of the individuals were receiving antiviral therapy, while 17 were treatment naïve. The quantitation of HCV RNA was done by a sensitive in-house real-time reverse transcription-PCR. When the viral loads in the two types of samples were compared, a correlation coefficient of 0.858 (P < 0.001) was found, indicating that plasma and whole blood are equally acceptable sources for testing for HCV RNA.

Exaggerated immune reactions predict the outcome of interferon therapy in patients with chronic hepatitis C

HCV plays a key role as chronic antigenic driver in inducing a clonal expansion of B-lymphocytes. The hypothesis that previous immunological pattern, when expression of an exaggerated immune reaction, could affect the response to IFN therapy was tested. Using a longitudinal database, the outcomes of 124 HCV-positive patients, genotype 1b only, with circulating HCV RNA, were analyzed by a retrospective cohort design. Immunological disorder-related clinical features and visceral organ involvement were thoroughly investigated in addition to laboratory data focusing on the presence of cryoglobulins, rheumatoid factor, antinuclear antibody, complement, circulating immunocomplexes and mono-oligoclonal gamma-globulin expansion. Eighty-four patients with and forty patients without abnormal immunological status, presenting a low fibrosis score, were identified. The whole naive population was treated by IFN monotherapy at the classical schedule for six or, alternatively, up to twelve months. Of the 124 patients, 28 showed a sustained response while 50 were non-responders and 46 were relapsers. Particularly, among the 84 patients with abnormalities of the immunological status, skin involvement was detected in 71 patients and hypocomplementemia was found in 69 patients, emerging as independent predictors for the lack of response. Conclusively, a peculiar immunological phenotype, ascertained by clinical and/or laboratory findings, is associated to a lack of IFN response and could be considered a further predictive factor.

Altered expression of glucagon-like peptide-1 and dipeptidyl peptidase IV in patients with HCV-related glucose intolerance

BACKGROUND AND AIM

The pathogenesis of hepatitis C virus (HCV)-associated glucose intolerance remains unclear. Glucagon-like peptide-1 (GLP-1), a gut hormone, synthesizes hepatic glycogen and is inactivated by dipeptidyl peptidase IV (DPPIV). The aims of this study were to investigate the alterations in the expression of GLP-1 and DPPIV in HCV-associated glucose intolerance.

METHODS

We enrolled patients with HCV- or hepatitis B virus (HBV)-related liver disease (n = 94 and 37, respectively), patients with inflammatory bowel disease (IBD; n = 14) as disease controls, and healthy controls (n = 48). The serum or tissue GLP-1 and DPPIV expression levels were determined by enzyme immunoassay, immunoblotting, or immunostaining. The hepatic glycogen content was assayed by periodic acid-Schiff staining.

RESULTS

The serum GLP-1 levels were significantly decreased in the HCV group (4.9 +/- 0.3 ng/mL) than those in the controls (7.5 +/- 0.6 ng/mL), the HBV group (7.0 +/- 0.5 ng/mL), or the IBD group (10.8 +/- 1.0 ng/mL, P < 0.01). Although the ileum GLP-1 expression was not significantly different between the controls and the HCV group, the DPPIV expression was significantly increased in the ileum, liver, and serum in the HCV group. Hepatic glycogen content was decreased to a greater extent in the HCV group than that in the HBV group (127.5 +/- 5.3 vs 187.7 +/- 6.6 arbitrary units; n = 19, P < 0.01).

CONCLUSION

We demonstrated the altered expressions of GLP-1 and DPPIV in patients with HCV-associated glucose intolerance. Since hepatic glycogen synthesis, a GLP-1 action, was impaired, the altered expressions of GLP-1 and DPPIV may be involved in the development of HCV-associated glucose intolerance.

Hepatitis C virus does not infect muscle, the intervertebral disk, or the meniscus in patients with chronic hepatitis C

Chronic infection with hepatitis C virus (HCV) is associated with several extrahepatic manifestations, including neuromuscular and joint disorders, and HCV RNA has been detected in muscle fibers of patients with myosistis and chronic hepatitis C. However, whether HCV infects muscle cells in patients without myosistis is unknown. The presence of HCV in other sites of the musculoskeletal system has not been investigated. In the present study the presence of HCV RNA was sought in muscle (2 cases), intervertebral disk (1 case) and meniscus (1 case) samples from patients with chronic hepatitis C. HCV RNA was not detected by reverse transcription and real-time polymerase chain reaction in any of the samples tested. In conclusion, the results do not support a direct role of HCV in musculoskeletal disorders associated with chronic hepatitis C.

Reliance of host cholesterol metabolic pathways for the life cycle of hepatitis C virus

Hepatitis C virus (HCV), a single-stranded positive-sense RNA virus of the Flaviviridae family, infects more than 170 million people worldwide and is the leading cause of liver failure in the United States. A unique feature of HCV is that the viral life cycle depends on cholesterol metabolism in host cells. This review summarizes the cholesterol metabolic pathways that are required for the replication, secretion, and entry of HCV. The potential application of drugs that alter host cholesterol metabolism in treating HCV infection is also discussed.

Association between chronic hepatitis B virus infection and diabetes among Asian Americans and Pacific Islanders

BACKGROUND

Asians have a higher prevalence of both diabetes (diabetes mellitus) and chronic hepatitis B virus infection compared to Caucasians. The aim of this study was to investigate whether hepatitis B virus infection was associated with diabetes mellitus among Asian Americans and Pacific Islanders.

METHODS

We reviewed the electronic medical records of 411 Asian and 424 Pacific Islanders seen at our medical centre over a 5-year period. Diabetes mellitus was defined by the presence of two or more random blood glucose levels > or =200mg/dL, an ICD-9 diagnostic code of diabetes mellitus, or use of medications for diabetes mellitus. Hepatitis B virus infection was defined by a positive HBsAg test.

RESULTS

Diabetes mellitus was diagnosed in 223 of the 835 subjects (26.7%), whereas hepatitis B virus infection was diagnosed in 56 (13.8%) of the 407 subjects tested for HBsAg. Overall, the prevalence of diabetes mellitus was significantly higher in patients with hepatitis B virus than in those without hepatitis B virus (58.9% vs. 33.3%, P<0.001), and this remained significant after adjustment for potential confounding variables (OR=3.17; 95% CI, 1.58-6.35). When Asians and Pacific Islanders were analysed separately, the prevalence of diabetes mellitus in patients with hepatitis B virus was significantly higher than in those without hepatitis B virus among Asians (65.0% vs. 27.5%, P<0.001) but not in Pacific Islanders (43.8% vs. 37.1%, P=0.60). Among the 390 subjects who were tested for both hepatitis B virus and hepatitis C virus, the prevalence of diabetes mellitus was 29.4% in uninfected subjects, 44.4% in patients with hepatitis B virus monoinfection, 47.2% in patients with hepatitis C virus monoinfection and 85.0% in patients with hepatitis B virus and hepatitis C virus coinfection (P<0.001).

CONCLUSIONS

Hepatitis B virus infection is strongly associated with diabetes mellitus among Asian Americans, but not in Pacific Islanders, whereas hepatitis C virus infection was associated with diabetes mellitus in both ethnic groups.

Clearance of HCV improves insulin resistance, beta-cell function, and hepatic expression of insulin receptor substrate 1 and 2

OBJECTIVES

Hepatitis C virus (HCV) infection is linked to greater insulin resistance. Although HCV itself is a candidate for the development of insulin resistance, the effects of antiviral treatment on impaired glucose metabolism remain unclear. The aim of this study is to examine the effects of clearance of HCV on insulin resistance, beta-cell function, and hepatic expression of insulin receptor substrate (IRS)1/2, central molecules for insulin signaling.

METHODS

We analyzed 89 biopsy-proven patients with chronic HCV infection. Patients received interferon-alpha or interferon-alpha plus ribavirin for 6 months and were classified into three groups at 6 months after the conclusion of antiviral therapy according to their response to antiviral therapy: sustained responders (N = 29), relapsers (N = 12), and nonresponders (N = 48). Insulin resistance and beta-cell function were assessed by the homeostasis model assessment method (HOMA-IR and HOMA-%B, respectively). Hepatic expression of IRS1/2 was evaluated by immunoblotting and immunostaining in 14 sustained responders.

RESULTS

In nonresponders and relapsers, there were no significant changes in HOMA-IR and HOMA-%B values after antiviral therapy. On the other hand, in sustained responders, HOMA-IR values significantly decreased to 1.7 +/- 0.8 from 3.1 +/- 1.1 (P < 0.05) after antiviral therapy. Similarly, HOMA-%B values significantly decreased to 90.6 +/- 10.0 from 113.7 +/- 15.3 (P < 0.05). Immunoblotting showed a threefold increase in IRS1/2 expression after clearance of HCV. Immunostaining revealed that greater IRS1/2 expression was seen in hepatocytes.

CONCLUSIONS

We showed that clearance of HCV improves insulin resistance, beta-cell function, and hepatic IRS1/2 expression.

Acute onset of type 1 diabetes accompanied by acute hepatitis C: the potential role of proinflammatory cytokine in the pathogenesis of autoimmune diabetes

A 22-year-old Japanese woman presented with general fatigue. Five days later, she demonstrated a body temperature of 39 degrees C and a loss in weight of 5kg. She thereafter became unconscious and was taken to Tomakomai City General Hospital. Urinary ketone body was positive, and plasma glucose was 1063mg/dl. The serum asparate aminotransferase and alanine aminotransferase levels were 158 and 1220IU/l, respectively. An arterial blood gas analysis showed metabolic acidosis. Glycated hemoglobin was 10.9%. Urinary C-peptide immnoreactivity was 11microg/day. Anti-glutamic acid decarboxylase antibody was 12.4U/ml. In general, islet-associated autoantibodies are detectable several years before the development of overt autoimmune diabetes, thus suggesting that an autoimmune reaction against beta-cells had already started in this case. On viral examinations, hepatitis C virus (HCV) antibody was negative, while HCV-RNA was positive. Based on these findings, she was diagnosed to have autoimmune diabetes and acute hepatitis C. In addition, her serum interleukin-18 level was elevated to 506pg/ml. The duration of diabetic characteristic symptoms before diagnosis is usually several weeks in most cases of autoimmune diabetes. However, it was extremely short in this case. Taken together, these findings suggested that the progression of autoimmune diabetes might have been accelerated due to the infection of HCV.

Evaluating the impact of hepatitis C virus (HCV) on highly active antiretroviral therapy-mediated immune responses in HCV/HIV-coinfected women: role of HCV on expression of primed/memory T cells

OBJECTIVE

To evaluate the impact of hepatitis C virus (HCV) on the immune system before receipt of highly active antiretroviral therapy (HAART) and on immune recovery after receipt of HAART among human immunodeficiency virus (HIV)/HCV-coinfected women enrolled in the Women's Interagency HIV Study.

METHODS

The study included 294 HIV-infected women who initiated HAART and attended 2 follow-up visits. The women were grouped on the basis of positive HCV antibody and HCV RNA tests. There were 148 women who were HCV antibody negative, 34 who were HCV antibody positive but RNA negative, and 112 who were HCV antibody and RNA positive. Immune recovery was measured by flow-cytometric assessment for markers of activation and maturation on CD4+ and CD8+ T cells. Data analysis used repeated measures of variance.Results. HIV/HCV coinfection is associated with an increased number of CD4+ and CD8+ primed/memory T cells. HIV/HCV coinfection, however, did not affect any further decreases in CD4+ or CD4+ and CD8+ naive/memory T cell counts or enhanced T cell activation. HIV/HCV coinfection also did not affect HAART responses in the CD4+ and CD8+ T cell compartment.

CONCLUSIONS

HCV does not affect immune responses to HAART in HIV/HCV-coinfected individuals but is associated with an expansion of CD4+ and CD8+ memory T cell subsets. Functional impairment in the CD4+ and CD8+ T cell compartments still needs to be assessed in coinfected patients.

Cyclosporine versus tacrolimus in patients with HCV infection after liver transplantation: Effects on virus replication and recurrent hepatitis

AIM: To determine the effects of the calcineurin inhibitors, cyclosporine and tacrolimus, on hepatitis C virus (HCV) replication and activity of recurrent hepatitis C in patients post liver transplantation.

METHODS: The data of a cohort of 107 patients who received liver transplantation for HCV-associated liver cirrhosis between 1999 and 2003 in our center were retrospectively analyzed. The level of serum HCV-RNA and the activity of recurrent hepatitis were compared between 47 patients who received either cyclosporine or tacrolimus as the primary immunosuppressive agent and an otherwise similar immunosuppressive regimen which did not lead to biliary complications within the first 12 mo after transplantation.

RESULTS: HCV-RNA increased within 3 mo after transplantation but the differences between the cyclosporine group and the tacrolimus group were insignificant (P = 0.49 at 12 mo). In addition, recurrent hepatitis as determined by serum transaminases and histological grading of portal inflammation and fibrosis showed no significant difference after 12 mo (P = 0.34).

CONCLUSION: Cyclosporine or tacrolimus as a primary immunosuppressive agent does not influence the induction or severity of recurrent hepatitis in HCV-infected patients after liver transplantation.

The haplotype block, NFKBIL1-ATP6V1G2-BAT1-MICB-MICA, within the class III-class I boundary region of the human major histocompatibility complex may control susceptibility to hepatitis C virus-associated dilated cardiomyopathy

Cardiomyopathy is a heart muscle disease with impaired stretch response that can result in severe heart failure and sudden death. A small proportion of hepatitis C virus (HCV)-infected patients may be predisposed to develop dilated cardiomyopathy (DCM) and hypertrophic cardiomyopathy (HCM). The molecular mechanisms involved in the predisposition remain unknown due in part to the lack of information on their genetic background. Because the human leukocyte antigen (HLA) region has a pivotal role in controlling the susceptibility to HCV-induced liver disease, we hypothesized that particular HLA alleles and/or non-HLA gene alleles within the human major histocompatibility complex (MHC) genomic region might control the predisposition to HCV-associated DCM (HCV-DCM) and/or HCV-associated HCM (HCV-HCM). Here, we present mapping results of the MHC-related susceptibility gene locus for HCV-associated cardiomyopathy by analyzing microsatellite and single nucleotide polymorphism markers. To delineate the susceptibility locus, we genotyped 44 polymorphic markers scattered across the entire MHC region in a total of 59 patients (21 HCV-DCM and 38 HCV-HCM) and 120 controls. We mapped HCV-DCM susceptibility to a non-HLA gene locus spanning from NFKBIL1 to MICA gene loci within the MHC class III-class I boundary region. Our results showed that HCV-DCM was more strongly associated with alleles of the non-HLA genes rather than the HLA genes themselves. In addition, no significant association was found between the MHC markers and HCV-HCM. This marked difference in the MHC-related disease susceptibility for HCV- associated cardiomyopathy strongly suggests that the development of HCV- DCM and HCV-HCM is under the control of different pathogenic mechanisms.

Importance of hepatitis C coinfection in the development of QT prolongation in HIV-infected patients

BACKGROUND

Case reports and unblinded studies suggest that human immunodeficiency virus (HIV) disease is associated with QT prolongation and torsade de pointes ventricular tachycardia. Hepatitis C coinfection is common in patients with HIV disease, and cirrhosis is also associated with QT prolongation. We therefore undertook a systematic analysis of the role of liver injury, nutritional state, and coinfection with hepatitis C in the etiology of QT prolongation in HIV disease.

METHODS

We performed a blinded, controlled retrospective cohort study of 1648 patients over a 3-year period at a university-affiliated municipal hospital. All electrocardiograms were included if patients with HIV disease had measurements of CD4 count and viral load within 3 months and serum electrolytes within 30 days (n = 816). Control subjects were chosen randomly from the general medicine service (n = 832). QT interval was measured in lead II and corrected for heart rate by Bazett's formula (QTc).

RESULTS

QTc was slightly but significantly longer in patients with HIV disease than in controls (443 +/- 37 vs 436 +/- 36 milliseconds, P < .001). Patients with hepatitis C had more pronounced QTc prolongation (452 +/- 41 vs 437 +/- 35 milliseconds, P < .001). CD4 count, HIV viral load, and HIV medications had no effect on QTc. When patients with hepatitis C were excluded from the analysis, there was no statistical difference between patients with HIV disease and controls (438 +/- 34 vs 436 +/- 36 milliseconds, P = .336). Multiple linear regression revealed that both HIV and hepatitis C infection predicted QTc prolongation, as did age, female sex, history of hypertension, use of opiates, low serum K+ and albumin, and high AST. Hepatitis C coinfection nearly doubled the risk of QTc of 470 milliseconds or greater in patients with HIV disease (29.6% vs 15.8%, P < .001).

CONCLUSIONS

Human immunodeficiency virus and hepatitis C infections both independently prolong QTc. Coinfection with hepatitis C greatly increases the likelihood of clinically significant QTc prolongation in patients with HIV disease.

HCV core protein localizes in the nuclei of nonparenchymal liver cells from chronically HCV-infected patients

Understanding the mechanism of hepatitis C virus (HCV) pathogenesis is an important part of HCV research. Recent experimental evidence suggests that the HCV core protein (HCcAg) has numerous functional activities. These properties suggest that HCcAg, in concert with cellular factors, may contribute to pathogenesis during persistent HCV infection. HCV is capable of infecting cells other than hepatocytes. Although the extrahepatic cellular tropism of HCV may play a role in the pathophysiology of this infection, the precise biological significance of the presence of HCV components in different liver cell types presently remains to be established. In this study, HCcAg was detected in nonparenchymal liver cells of six patients out of eight positive for serum HCV RNA. Immunostaining with anti-HCcAg mAbs revealed the presence of this protein in different liver cell types such as lymphocytes, Kupffer, polymorphonuclear, pit, endothelial, stellate, and fibroblast-like cells. Interestingly, HCcAg was immunolabeled not only in the cytoplasm but also in the nucleus of these cells. Remarkably, HCcAg co-localized with large lipid droplets present in stellate cells and with collagen fibers in the extracellular matrix. Moreover, HCcAg was immunolabeled in bile canaliculus suggesting the involvement of the biliary system in the pathobiology of HCV. Data suggest that nonparenchymal liver cells may constitute a reservoir for HCV replication. Besides, HCcAg may contribute to modulate immune function and fibrosis in the liver as well as steatosis.

Prevalence of gallbladder disease among persons with hepatitis C virus infection in the United States

Although cirrhosis is a known risk factor for gallstones, little is known about gallbladder disease (GBD) in individuals with hepatitis C virus (HCV) infection. We determined the association between chronic HCV infection and GBD in a representative sample of adults in the United States. Data on HCV infection and GBD were available for 13,465 persons 20 to 74 years of age who participated in the Third National Health and Nutrition Examination Survey. The presence of GBD (gallstones or cholecystectomy) was determined using abdominal ultrasonography, and HCV infection was assessed via a positive HCV antibody test and a positive HCV RNA test. Overall, 1.6% of adults (95% CI, 1.1-2.1) had chronic HCV infection and 12.5% (95% CI, 11.3-13.7) had GBD. After adjusting for potential confounding variables, the odds of gallstones (OR = 3.20; 95% CI, 1.08-9.45) and cholecystectomy (OR = 4.57; 95% CI, 1.57-13.27) among HCV-positive men was significantly higher compared with HCV-negative men. In contrast, the adjusted odds of gallstones (OR = 2.55; 95% CI, 0.58-11.25) and cholecystectomy (OR = 0.70; 95% CI, 0.21-2.37) among HCV-positive women was not significantly higher. The odds of GBD increased significantly with the severity of liver disease as assessed via elevated serum bilirubin levels and low levels of serum albumin and platelets. In conclusion, chronic HCV infection was strongly associated with GBD among men but not women in the United States, and GBD was more common in adults with severe liver disease.

Viral kinetics in hepatitis C or hepatitis C/human immunodeficiency virus-infected patients

BACKGROUND AND AIMS

Kinetic modeling of hepatitis C virus (HCV) response to interferon (IFN)-based therapy provides insights into factors associated with treatment outcomes. HCV/human immunodeficiency virus (HIV)-co-infected patients show lower response rates vs. HCV-monoinfected patients. Reasons for this remain unclear. This study evaluated kinetic parameters and treatment responses in co-infected vs monoinfected patients.

METHODS

Co-infected patients were randomized within a US multicenter trial (ACTG 5071) to receive pegylated-interferon (PEG-IFN) alfa-2a + ribavirin vs. IFN alfa-2a + ribavirin. Monoinfected controls were matched prospectively for treatment, genotype, age, sex, race, and histology. Quantitative HCV-RNA testing was performed at hours 0, 6, 12, 24, 48, and 72; days 7, 10, 14, 28, and 56; and weeks 12, 24, 48, and 72.

RESULTS

Twelve HCV/HIV-co-infected and 15 HCV-monoinfected patients underwent viral kinetic sampling. Among HIV-positive patients the mean CD4(+) count was 325 cells/mm(3). Seventy-five percent of patients were genotype 1. The HCV-RNA level was undetectable at 72 weeks in 25% and 40% of co-infected and monoinfected patients, respectively. Phase 1/2 declines, free virus clearance rate, and infected hepatocyte death rate were not affected by co-infection status but differed by treatment. Efficiency (epsilon) > or = 90% at 60 hours was associated with viral clearance ( P = .02). Modeling with pooled parameters suggests baseline viral load is a key factor in time to response in this cohort. Predicted clearance time increased by 28% in co-infected patients.

CONCLUSIONS

Co-infection status did not affect key kinetic parameters. Among kinetic parameters, efficiency was associated significantly with viral clearance. Co-infected patients may require longer treatment duration than monoinfected patients given their generally higher baseline viral loads.

Pathophysiological Characteristics and Responsiveness to Neurohormonal Antagonism in Idiopathic Dilated Cardiomyopathy Patients With Antihepatitis C Virus Antibody

A high prevalence of hepatitis C virus (HCV) infection has been reported among idiopathic dilated cardiomyopathy (DCM) patients. We examined the prevalence of DCM patients with HCV antibody, and the pathophysiological characteristics and responsiveness to neurohormonal antagonism in DCM with HCV. HCV antibodies were determined in 540 patients with cardiac diseases. In 117 DCM patients, clinicopathologic data were evaluated before and 1 year after angiotensin converting enzyme inhibitor and/or beta-blocker (ACE-inhibitor/BB) administration and their prognosis was followed-up for a mean of 72 +/- 41 months. HCV antibodies were found in 12 of 135 DCM patients (8.9%) and in 37 of 405 patients without DCM (9.1%) (P = NS). At baseline, contrary to DCM without HCV, DCM with HCV was associated (P < 0.05) with greater left ventricular (LV) end-diastolic and end-systolic dimension, LV mass, and myocardial diameter in endomyocardial biopsy, and lower % fractional shortening. By multivariate analysis, HCV infection was independently associated with larger LV end-systolic dimension among DCM patients (P = 0.005). The advanced LV dilatation and hypertrophy in DCM with HCV decreased more in response to the ACE-inhibitor/BB therapy compared to DCM without HCV. There were no differences between DCM patients with and without HCV in survival and cardiac event-free rates. In summary, although HCV infection appears not to be the specific cause of DCM, HCV may enhance ventricular remodeling leading to heart failure among DCM patients. Nevertheless, the advanced ventricular remodeling with HCV was adequately reversed by neurohormonal antagonism, and did not lead to an unfavorable outcome.

Pharmacokinetics of pegylated interferons: what is misleading?

Available pegylated interferon (PEG-IFN) products confer enhanced therapeutic efficacy when compared with their IFN counterparts, and the added convenience of once-weekly dosing with no novel toxicities. PEG optimises the action of the IFNs by decreasing clearance rates, thereby allowing serum concentrations to remain constant over the dosing period. The length and shape of each PEG moiety are crucial in determining the effect on pharmacokinetic and pharmacodynamic properties. In vitro activity decreases with increasing PEG size, therefore the reduction of potency at the molecular receptor should be compensated by the prolonged residence in blood, or by the higher total drug exposure. Moreover, in hepatitis C, viral suppression in blood alone may not be enough, HCV reservoirs outside the blood may play a role in HCV persistence, therefore drugs with a low volume of distribution offer much less chance for infiltrating extravascular tissue and may explain its higher relapse rate. The case of PEG-IFNs for use in the treatment of chronic hepatitis C clearly demonstrates the potential for different characteristics among PEG conjugates.

Expression of hepatitis C virus proteins in epithelial intestinal cells in vivo

Previous work on hepatitis C virus (HCV) led to the discovery of a new form of virus particle associating virus and lipoprotein elements. These hybrid particles (LVP for lipo-viro-particles) are enriched in triglycerides and contain at least apolipoprotein B (apoB), HCV RNA and core protein. These findings suggest that LVP synthesis could occur in liver and intestine, the two main organs specialized in the production of apoB-containing lipoprotein. To identify the site of LVP production, the genetic diversity and phylogenetic relationship of HCV quasispecies from purified LVP, whole serum and liver biopsies from chronically infected patients were studied. HCV quasispecies from LVP and liver differed significantly, suggesting that LVP were not predominantly synthesized in the liver but might also originate in the intestine. The authors therefore searched for the presence of HCV in the small intestine. Paraffin-embedded intestinal biopsies from 10 chronically HCV-infected patients and from 12 HCV RNA-negative controls (10 anti-HCV antibody-negative and two anti-HCV antibody-positive patients) were tested for HCV protein expression. HCV NS3 and NS5A proteins were stained in small intestine epithelial cells in four of the 10 chronically infected patients, and not in controls. Cells expressing HCV proteins were apoB-producing enterocytes but not mucus-secreting cells. These data indicate that the small intestine can be infected by HCV, and identify this organ as a potential reservoir and replication site. This further emphasizes the interaction between lipoprotein metabolism and HCV, and offers new insights into hepatitis C infection and pathophysiology.

Association of diabetes and hepatitis C infection: epidemiologic evidence and pathophysiologic insights

Up to one third of patients with chronic hepatitis C virus (HCV) develop type 2 diabetes mellitus (DM). This prevalence is much higher than that observed in the general population, and in patients with other chronic liver diseases such as hepatitis B virus, alcoholic liver disease, and primary biliary cirrhosis. Further, HCV seropositivity in patients with DM appears to be higher than in the general population. Post- liver transplantation DM also appears to be higher among patients with HCV. In this article, we review the epidemiologic association between HCV and DM, highlighting the most recent pathophysiologic insights into the mechanisms underlying this association.

Development and application of a mixed microarray in detection of genes of HBV and HCV

AIM: To develop a DNA microarray to detect hepatitis virus B (HBV) DNA, hepatitis virus C (HCV) RNA, HBV YMDD mutant and HCV genotype simultaneously. At the same time, the chip was compared with other techniques to evaluate its prospect in clinical application.

METHODS: A set of probes was designed to detect HBV DNA, HCV RNA, HBV YMDD mutant and HCV genotype. The probes were synthesized by DNA synthesizer. The microarray was prepared by spotting the probes onto the specially treated glass sliders. Serum samples were collected from inpatients and outpatients at the Department of Infectious Diseases, the Third Affiliated Hospital of Zhongshan University. Among the samples, 20 were comfirmed HBV DNA positive by fluorescent quantitation PCR, 20 were HCV RNA positive, 20 were comfirmed YMDD mutant by mismatched PCR, 10 were HBV DNA and HCV RNA negative. HBV DNA and HCV RNA were extracted from the serum, then amplified by asymmetric PCR or RT-PCR in the presence of sense fluorescein labeled primers. The products of HBV YMDD and HCV NS-5 were purified and sequenced. Following the hybridization of amplified products on the microarrays, detection was carried out by the fluorescence scanner. The detection results were obtained by analyzing the intensity and ratio of the fluorescence signals using image analysis software.

RESULTS: For the HBV DNA positive samples and HCV RNA positive samples, an intensive signal was observed at the point of corresponding probes on the microarrays. In detection of YMDD mutant, the coincident rate of the microarray and the mismatched PCR was 75%, the coincident rate of microarray and sequencing was 95%. In detection of HCV genotype, the coincident rate of microarray and sequencing was 75%.

CONCLUSION: The technology of microarray appears to be versatile, with a great sensitivity and specifity in detection of HBV and HCV. Furthermore, it can find co-infection of different virus strains. But it has some false negative rate and false positive rate in HCV genotyping.

Liver fibrosis in chronic viral hepatitis: An ultrasonographic study

AIM: To select valuable ultrasonographic predictors for the evaluation of hepatic inflammation and fibrosis degree in chronic hepatitis, and to study the value of ultrasonography in the evaluation of liver fibrosis and compensated liver cirrhosis in comparison with serology and histology.

METHODS: Forty-four ultrasonographic variables were analyzed and screened using color Doppler ultrasound system in 225 patients with chronic viral hepatitis and compensated liver cirrhosis. The valuable ultrasonographic predictors were selected on the basis of a comparison with histopathological findings. The value of ultrasonography and serology in the evaluation of liver fibrosis degree and the diagnosis of compensated liver cirrhosis was also studied and compared. Meanwhile, the influencing factors on ultrasonographic diagnosis of compensated liver cirrhosis were also analyzed.

RESULTS: By statistical analysis, the maximum velocity of portal vein and the degree of gall-bladder wall smoothness were selected as the valuable predictors for the inflammation grade (G), while liver surface, hepatic parenchymal echo pattern, and the wall thickness of gall-bladder were selected as the valuable predictors for the fibrosis stage (S). Three S-related independent ultrasonographyic predictors and three routine serum fibrosis markers (HA, HPCIII and CIV) were used to discriminate variables for the comparison of ultrasonography with serology. The diagnostic accuracy of ultrasonography in moderate fibrosis was higher than that of serology (P < 0.01), while there were no significant differences in the general diagnostic accuracy of fibrosis as well as between mild and severe fibrosis (P < 0.05). There were no significant differences between ultrasonography and serology in the diagnosis of compensated liver cirrhosis. However, the diagnostic accuracy of ultrasonography was higher in inactive liver cirrhosis and lower in active cirrhosis than that of serology (both P < 0.05). False positive and false negative results where found when the diagnosis of compensated liver cirrhosis was made by ultrasonography.

CONCLUSION: There are different ultrasonographic predictors for the evaluation of hepatic inflammation grade and fibrosis stage of chronic hepatitis. Both ultrasonography and serology have their own advantages and disadvantages in the evaluation of liver fibrosis and compensated liver cirrhosis. Combined application of the two methods is hopeful to improve the diagnostic accuracy.

Allograft transmission of hepatitis C virus infection from infected donors in cardiac transplantation

BACKGROUND

The frequency and outcome of hepatitis C virus (HCV) infection in recipients of hearts from HCV-infected donors remains poorly characterized.

METHODS

Between 1991 and 1999, 10 anti-HCV-negative patients received hearts from donors who were anti-HCV and HCV RNA-positive. Each recipient was tested for anti-HCV and HCV RNA and serially evaluated for liver dysfunction. Recipient records were reviewed for cumulative steroid boluses in the first posttransplant year and other components of the immune suppression regimen. We analyzed recipient outcome in relation to the virologic status of the donor, including the level of HCV RNA and genotype and the type of antirejection therapy.

RESULTS

All 10 recipients became HCV RNA positive. Donor-recipient pairs expressed identical genotypes in each instance. Six of nine evaluable recipients developed biochemical evidence of hepatitis. Recipients with genotype 1 (1a, 1b) accounted for five of the six cases, and all patients with genotype 1 developed hepatitis. Severe liver injury occurred in two patients. Two deaths occurred, both of which were genotype 1 patients who had been given multiple boluses of corticosteroids in the first posttransplant year. No definite relationship between viral load in the donor and recipient outcome was found.

CONCLUSION

Transmission of HCV infection from cardiac donors who are viremic at the time of organ donation occurs with high frequency and can cause severe hepatitis. Hearts from infected patients should probably be restricted to those recipients who already have evidence for hepatitis C or are in need of emergent transplantation.

RNA interference: Antiviral weapon and beyond

RNA interference (RNAi) is a remarkable type of gene regulation based on sequence-specific targeting and degradation of RNA. The term encompasses related pathways found in a broad range of eukaryotic organisms, including fungi, plants, and animals. RNA interference is part of a sophisticated network of interconnected pathways for cellular defense, RNA surveillance, and development and it may become a powerful tool to manipulate gene expression experimentally. RNAi technology is currently being evaluated not only as an extremely powerful instrument for functional genomic analyses, but also as a potentially useful method to develop specific dsRNA based gene-silencing therapeutics. Several laboratories have been interested in using RNAi to control viral infection and many reports in Nature and in Cell show that short interfering (si) RNAs can inhibit infection by HIV-1, polio and hepatitis C viruses in a sequence-specific manner. RNA-based strategies for gene inhibition in mammalian cells have recently been described, which offer the promise of antiviral therapy.

Mutations in nonstructural 5A gene of hepatitis C virus and its response to interferon alfa

AIM

To investigate the relationship between NS5A_2209-2248 sequences and response to interferon therapy, and whether there is an IFN sensitivity determining region(ISDR) in the region of NS5A_2209-2248.

METHODS

We analyzed 11 patients with chronic HCV 1b infection who had received interferon alfa therapy for six months. Pretreatment serum samples were analyzed. The amino acid sequence of NS5A_2209-2248 was determined by direct sequencing of the HCV genome amplified by the polymerase chain reaction.

RESULTS

Among the 11 patients, only 1 was intermediate type, all the others were wild type. 2 of wild type patients showed complete response. Others were nonresponders. There was no significant difference in nucleotide and amino acid sequences between the two groups.The nucleotide and amino acid sequences changed after IFN treatment in one nonresponder.

CONCLUSION

The NS5A_2209-2248 region was highly conservative. In Chinease patients with chronic HCV 1b infection, there was no correlation between response to interferon and mutations in the NS5A gene. HCV quasispecies changed after IFN therapy.

Construction and expression of chrimeid plasmid pHCV-IgFc

AIM

To construct a recombinant cherimal plasmid of HCV-Fc that can express HCV core protein and IgG Fc.

METHODS

The HCV core gene derived from the plasmid pBRTM/HCV1-3011 by using polymerase chain reaction (PCR) was inserted into the backward position of cytomegalovirus (CMV) immediate early promotor element of Fc plasmid (pIgFc), then the recombinant plasmid pHCV-IgFc was obtained.

RESULTS

The insert DNA of pHCV-IgFc was HCV core and Fc gene conformed by endonuclease, PCR and sequencing. HCV core gene and Fc gene expressed transiently with Lipofectamine 2000 coated in human hepatoblastoma 7721 cells, which was conformed by immunofluorescence.

CONCLUSION

Recombinant cherimal plasmid vector pHCV-IgFc can express HCV core and Fc gene transiently in 7721 cells. It may be useful in transfection of dendritic cells and development into dendritic cell vaccince.

Effect of alpha 2b interferon on inducement of mIL-2R and treatment of HCV in PBMC from patients with chronic viral hepatitis C

AIM: To study the level of membrane interleukin-2 receptor (mIL-2R) on surface of peripheral blood mononuclear cells (PBMC) and the therapeutic efficacy of alpha 2b interferon on the treatment of HCV-RNA in PBMC of patients with chronic hepatitis C and to compare the negative rates of HCV-RNA in PBMC, HCV-RNA and anti-HCV in serum.

METHODS: Before and after treatment of alpha 2b interferon, the level of mIL-2R of patients with chronic hepatitis C was detected by biotin-streptavidin (BSA). The therapeutic group (26 cases) was treated with alpha 2b interferon (3 MU/d) and control therapeutic group (22 cases) was treated with routine drugs (VitC, aspartic acid). The total course of treatment with alpha 2b interferon and routine drug was six months and per course of the treatment was three months. The levels of HCV-RNA in PBMC, HCV-RNA and anti-HCV in serum were detected before and after a course of the treatment.

RESULTS: Before and after treatment of alpha 2b interferon and routine drugs, the levels of mIL-2R in silence stage were (3.44 ± 0.77)% and (2.95 ± 0.72)%, the levels of mIL-2R in inducement stage were (33.62 ± 3.95)% and (30.04 ± 3.73)%. There was a significant difference between two groups (P < 0.01-P < 0.05). After treatment of alpha 2b interferon with 3 MU/d for two courses of the treatment, the total negative rates of HCV-RNA in the PBMC and HCV-RNA, anti-HCV in serum were 42.31% (11/26), 57.69% (15/26), 65.38%(17/26) respectively. After the treatment of routine drug, the negative rates of HCV-RNA in PBMC and HCV-RNA, anti-HCV in serum were 13.64% (3/22), 22.73% (5/22), 27.27% (6/22) respectively. There was high significant difference in the group treated with alpha 2b interferon and the group treated with routine drugs (P < 0.01-P < 0.05).

CONCLUSION: The mIL-2R can be induced by alpha 2b interferon during the treatment. The alpha 2b interferon has a definite effect on the treatment of HCV-RNA in PBMC. The curative effect of alpha 2b interferon is better than that of the routine drugs.

Interaction between hepatitis C virus core protein and translin protein- a possible molecular mechanism for hepatocellular carcinoma and lymphoma caused by hepatitis C virus

AIM: To investigate the interaction between hepatitis C virus core protein and translin protein and its role in the pathogenensis of hepatocellular carcinoma and lymphoma.

METHODS: With the components of the yeast two hybrid system 3,“ bait” plasmids of HCV core the gene was constructed. After proving that hepatitis C virus core protein could be firmly expressed in AH109 yeast strains, yeast two- hybrid screening was performed by mating AH109 with Y187 that transformed with liver cDNA library plasmids - pACT2 and then plated on quadrople dropout (QDO) medium and then assayed for α-gal activity. Sequencing analysis of the genes of library plasmids in yeast colonies that could grow on QDO with α-gal activity was performed. The interaction between HCV core protein and the protein we obtained from positive colony was further confirmed by repeating yeast two - hybrid analysis and coimmunoprecipitation in vitro.

RESULTS: A gene from a positive colony was the gene of translin, a recombination hotspot binding protein. The interaction between HCV core protein and translin protein could be proved not only in yeast, but also in vitro.

CONCLUSION: The core protein of HCV can interact with translin protein. This can partly explain the molecular mechanism for hepatocellular carcinoma and lymphoma caused by HCV.

Inhibitory effect of IRES specific inhibitor RNA on HCV IRES mediated protein translation

AIM: To explore the inhibitory effect of internal ribosome entry site (IRES) specific inhibitor RNA (IRNA) on HCV IRES mediated protein translation in vivo.

METHODS: Human hepatic carcinoma cell line (HHCC) was transfected with the eukaryotic vectors of IRNA or mIRNA (pcRz-IRNA or pcRz-mIRNA), and then selected with G418 for 4 weeks. HHCC expressing IRNA or mIRNA was cotransfected with pCMVNCRluc containing HCV IRES. HHCC stably expressing pcHCVcluc was transfected with pcRz-IRNA, and pcRz-mIRNA, respectively, the luciferase activity was examined at desired time post-transfection.

RESULTS: The pCMVNCRluc was efficiently suppressed in HHCC expressing IRNA rather than the cell line expressing mIRNA. The IRES specific IRNA inhibited expression of HCV IRES mediated luc gene by 20% to 80% in pcHCVcluc expressing cell after transfection; However, no inhibitory effect of the mutant IRNA was observed.

CONCLUSION: pcHCVcluc could be expressed successfully in HHCC, and IRNA inhibited HCV IRES mediated gene expression in vivo.

Construction, package and identification of replication-deficient recombinant adenovirus expression vector of HCV C

AIM: To construct a replication-deficient recombinant adenovirus expression vector of HCV C.

METHODS: The HCV core gene was cloned at the downstream of CMV promoter of the adenoviral shuttle plasmid pAd. CMV-link. 1, and the resultant recombinant plasmid pAd. HCV-C was cotransfected into 293 cell together with plasmid pJM17 containing adenoviral genome, then the adenovirus expression vector was obtained, and identified by infecting test, electronic microscope observation and PCR co-amplification. The plasmid pAd. HCV-C was identified by endonuclease, PCR and sequencing. The expressive activity of adenovirus vector was identified by immunofluorescence and Western blot.

RESULTS: HCV core gene in the inserted DNA of pAd. HCV-C was confirmed by endonuclease, PCR and sequencing. Results of infecting test, electronic microscopic observation and PCR co-amplification showed that the adenovirus vector had been constructed successfully. Expression of HCV core antigen was proved in the HepG2 cells by immunofluorescence and Western blot.

CONCLUSION: The replication-deficient recombinant adenovirus vector can express HCV core antigen in HepG2 cells. This study established a foundation for further study on HCV vaccines and gene therapy for hepatitis C.

Localization of TRAIL/TRAILR in fetal pancreas

AIM: To observe the localization of TRAIL/TRAIR (DR4, DR5, DcR1, DcR2) in the fetal pancreas.

METHODS: Fetal pancreas of 32 wk of pregnancy were obtained from induced abortions, embedded in paraffin, and 4-μm sections were prepared. The localization of TRAIL/TRAILR in fetal pancreas was investigated by fluorescence immunohistochemical method combined with laser scanning confocal microscopy.

RESULTS: TRAIL immunoreactive cells were mainly located on the periphery of the pancreas islets. There were a few DcR1 and DcR2 positive cells whereas there were no immunoreactive cells of DR4 and DR5 in the pancreas islets. In the acini and the ducts of the exocrine pancreas there were no TRAIL/TRAILR immunoreactive cells.

CONCLUSION: This study not only describes the distribution of TRAIL/TRAILR in the fetal pancreas, but also provides a morphological basis for deducing the function of TRAIL/TRAILR in pancreas, suggesting that in normal pancreatic islets, the pancreatic cells are resistant towards apoptosis too.

Investigation of HGV and TTV infection in sera and saliva from non-hepatitis patients with oral diseases

AIM: To determine the frequencies of HGV and TTV infections in serum and saliva samples of non-hepatitis patients with oral diseases in Hangzhou area, and to understand the correlation between detected results of HGV RNA and/or TTV DNA in sera and in saliva from the same patients.

METHODS: RT-nested PCR for HGV RNA detection and semi-nested PCR for TTV DNA detection were performed in the serum and saliva samples from 226 non-hepatitis patients with oral diseases, and nucleotide sequence analysis.

RESULTS: Twenty-seven (11.9%) and 21 (9.3%) of the 226 serum samples were only positive for HGV RNA and TTV DNA, respectively. 10 (4.4%) and 9 (3.9%) of the 226 saliva samples were only positive for HGV RNA and TTV DNA, respectively. And 7 (3.1%) of the serum samples and 2 (0.9%) of the saliva samples showed the positive amplification results for both HGV RNA and TTV DNA. 12 saliva samples from the 34 patients (35.3%) with HGV or HGV/TTV viremia and 11 saliva samples from the 28 patients (39.3%) with TTV or HGV/TTV viremia were HGV RNA detectable, respectively, including two patients positive for both HGV RNA and TTV DNA in serum and saliva samples. No saliva samples from the 226 patients were found to be HGV RNA or TTV DNA detectable while their serum samples were negative for HGV or TTV. Homologies of the nucleotide sequences of HGV and TTV amplification products from the serum and saliva samples of the two patients compared with the reported sequences were 88.65%-91.49% and 65.32%-66.67%, respectively. In comparison with the nucleotide sequences of amplification products between serum and from saliva sample from any one of the two patients, the homologies were 98.58% and 99.29% for HGV, and were 98.65% and 98.20% for TTV, respectively.

CONCLUSION: Relatively high carrying rates of HGV and/or TTV in the sera of non-hepatitis patients with oral diseases in Hangzhou area are demonstrated. Parts of the carriers are HGV and/or TTV positive in their saliva. The results of this study indicate that dentists may be one of the populations with high risk for HGV and/or TTV infection, and by way of saliva HGV and TTV may be transmitted among individuals.

Preparation of human single chain Fv antibody against hepatitis C virus E2 protein and its identification in immunohistochemistry

AIM: To screen human single chain Fv antibody (scFv) against hepatitis C virus E2 antigen and identify its application in immunohistochemistry.

METHODS: The phage antibody library was panned by HCV E2 antigen, which was coated in microtiter plate. After five rounds of biopanning, 56 phage clones were identified specific to HCV E2 antigen. The selected scFv clones were digested by Sfi I/Not I and DNA was sequenced. Then it was subcloned into the vector pCANTAB5E for expression as E-tagged soluble scFv. The liver tissue sections from normal person and patients with chronic hepatitis B and chronic hepatitis C were immunostained with HCV E2 scFv antibody.

RESULTS: The data of scFv-E2 DNA digestion and DNA sequencing showed that the scFv gene is composed of 750 bp. ELISA and immunohistochemistry demonstrated that the human single chain Fv antibody against hepatitis C E2 antigen has a specific binding character with hepatitis virus E2 antigen and paraffin-embedded tissue, but did not react with liver tissues from healthy persons or patients with chronic hepatitis B.

CONCLUSION: We have successfully screened and identified HCV E2 scFv and the scFv could be used in the immunostaining of liver tissue sections from patients with chronic hepatitis C.

Construction of HCV-core gene vector and its expression in cholangiocarcinoma

AIM: To establish an experimental model for exploring the role of hepatitis C virus (HCV) in the development of cholangiocarcinoma.

METHODS: Recombinant plasmid of HCV-core gene was constructed with molecular cloning technique and transfected into QBC939 cells with lipofection. After it was selected with G418, resistant colonies were obtained. The colonies were analysed by immunocytochemistry and Western blotting.The morphology was observed under transmission electron microscope(TEM) and microscope.

RESULTS: The recombinant plasmid was proved to carry the target gene by PCR and restriction enzymed mapping. Moreover, it could express HCV-C protein efficiently in QBC939 cells. The HCV-like particles were found in the cytoplasm by electron microscope, which were spherical with a diameter of 50 nm-80 nm possessing outer membrane.The transfected cells had lower differentiation and higher malignant degree under microscope.

CONCLUSION: Because HCV-core gene could express steadily in cholangiocarcinoma cells,the transfected tumor cells(QBC939-HCVC) could be used to study the effect of HCV in the development of cholangiocarcinoma.

Distribution of nitric oxide synthase in stomach myenteric plexus of rats

AIM: To study the distribution of nitric oxide synthase (NOS) in rat stomach myenteric plexus.

METHODS: The distribution of NOS in gastric wall was studied in quantity and location by the NADPH-diaphorase (NDP) histochemical staining method and whole mount preparation technique.

RESULTS: NOS was distributed in whole stomach wall, most of them were located in myenteric plexus, and distributed in submucosal plexus. The shape of NOS positive neurons was basically similar, most of them being round and oval in shape. But their density, size and staining intensity varied greatly in the different parts of stomach. The density was 62 ± 38 cells/mm² (antrum), 43 ± 32 cells/mm² (body), and 32 ± 28 cells/mm² (fundus), respectively. The size and staining intensity of NOS positive neurons in the fundus were basically the same, the neurons being large and dark stained, while they were obviously different in antrum. In the body of the stomach, the NOS positive neurons were in an intermediate state from fundus to antrum. There were some beadlike structures which were strung together by NOS positive varicosities in nerve fibers, some were closely adherent to the outer walls of blood vessels.

CONCLUSION: Nitric oxide might be involved in the modulation of motility, secretion and blood circulation of the stomach, and the significant difference of NOS positive neurons in different parts of stomach myenteric plexus may be related to the physiologic function of stomach.

Identification of the epitopes on HCV core protein recognized by HLA-A2 restricted cytotoxic T lymphocytes

AIM

To identify hepatitis C virus(HCV) core protein epitopes recognized by HLA-A2 restricted cytotoxic T lymphocyte (CTL).

METHODS

Utilizing the method of computer prediction followed by a 4h(51)Cr release assay confirmation.

RESULTS

The results showed that peripheral blood mononuclear cells (PBMC) obtained from two HLA-A2 positive donors who were infected with HCV could lyse autologous target cells labeled with peptide "ALAHGVRAL (core 150-158)". The rates of specific lysis of the cells from the two donors were 37.5% and 15.8%, respectively. Blocking of the CTL response with anti-CD4 mAb caused no significant decrease of the specific lysis. But blocking of CTL response with anti-CD8 mAb could abolish the lysis.

CONCLUSION

The peptide (core 150-158) is the candidate epitope recognized by HLAA2 restricted CTL.