Moderate alcohol intake increases fibrosis progression in untreated patients with hepatitis C virus infection.

Although excessive alcohol consumption in combination with hepatitis C virus (HCV) infection is known to increase the risk of liver cirrhosis, the effect of moderate alcohol intake remains to be elucidated. The aim of this study was to evaluate the effect of moderate alcohol consumption on fibrosis progression in HCV infection. A group of 78 patients with HCV infection and moderate alcohol consumption were analysed retrospectively. All patients had undergone two liver biopsies, with a median time between biopsies of 6.3 years, and had not received any antiviral therapy. Their lifetime drinking history was recorded. All patients except one had daily alcohol consumption below 40 g of ethanol (median 4.8 g/day, interquartile range 1.1-11.6 g/day) during the period between the biopsies. The patients whose liver fibrosis had deteriorated had a higher total alcohol consumption and higher drinking frequency between the biopsies. The degree of fibrosis progression was greater in patients with a total alcohol intake and drinking frequency above the median level for the group. A multiple logistic regression analysis showed that drinking frequency and time between biopsies were independently associated with fibrosis progression. Hence, even moderate alcohol intake seems to increase fibrosis progression in HCV-infected patients. From that point of view, total abstention ought to be recommended. If this is not achieved, occasional use of alcohol is probably less harmful than daily drinking for patients with low or moderate alcohol consumption.

Immunoregulatory role of secreted glycoprotein G from respiratory syncytial virus.

The secretory glycoprotein (Gs) of respiratory syncytial virus (RSV) was enriched and investigated for its effects on T cells specific for RSV and unrelated antigens. Gs exhibited a dose dependent suppression of lymphoproliferative responses in peripheral blood mononuclear cells (PBMCs), specific for mycobacterial lysates or tetanus toxoid. However, Gs did not inhibit live RSV specific T cell responses. These results suggest that Gs may suppress immune response to unrelated antigens, but should not interfere with the overall development of RSV specific immunity.

Monitoring virological responses to interferon-ribavirin and interferon monotherapy of chronic hepatitis C re-treated due to relapse or non-response.

Adding the nucleoside analog ribavirin (RBV) to interferon (IFN) for treatment of HCV has improved the sustained response rates, but the mechanism by which RBV mediates viral clearance is not fully understood. In this study, a highly sensitive method (Codes Amplicor HCV Monitor) was used to monitor the early (first 12 weeks of therapy) and long-term virological response in 20 patients who were treated first with IFN and later, due to non-sustained response, with IFN-RBV. All 10 IFN relapsers displayed a prompt virological response at week 4 to both IFN and IFN-RBV therapy; nine of them showed a sustained response to IFN-RBV. Out of 10 IFN non-responders, five showed a sustained response to IFN-RBV. Four of these were HCV RNA-negative at week 4 of IFN-RBV therapy and two of them had a transient early virological response (RNA-negative at weeks 4-8) to IFN alone. Overall, of the 14 patients (nine IFN relapsers, five IFN non-responders) with a sustained response to IFN-RBV, 11 and 13 had HCV RNA below 2000 copies/ml at week 4 of IFN and IFN-RBV, respectively, as compared with one and one of six patients without a sustained response to IFN-RBV (p < 0.02). Thus, addition of RBV to IFN increased both viral clearance during the first 12 weeks of therapy and the rate of sustained response. Loss of viremia at week 4 of IFN was associated with a sustained response to IFN-RBV and was seen in 11 of 13 patients (85%) with genotypes 2 or 3, as compared with one of seven patients (14%) with genotype 1 (p = 0.0044).

Chronic hepatitis C in Sweden: genotype distribution over time in different epidemiological settings.

Hepatitis C virus (HCV) strains are divided into 6 genotypes and several subtypes. Recent studies reported a change in the relative frequency of genotypes within certain regions. We studied the HCV genotype in 312 Swedish patients with chronic hepatitis C, using a core region primer-specific PCR, and grouped the patients according to parenteral risk factors. The date of infection could be estimated in 127 cases. Genotypes 1a (35%) and 3 (31%) were the most common genotypes, followed by genotype 2 (17%), while only 6% had genotype 1b. Genotype 3 was relatively more frequent among subjects infected sexually or by intravenous drug use. The genotype distribution was different from that in studies from other parts of the world, with a lower frequency of genotype 1 (especially 1b) and a higher frequency of genotype 3. The frequency of genotype 1b has decreased and genotype 3 increased over time. The reasons for a different distribution of genotypes in Sweden, compared with other countries, might be a relatively recent introduction of HCV into the population, or a different pattern of transmission.

Interobserver study of liver histopathology using the Ishak score in patients with chronic hepatitis C virus infection.

AIMS/BACKGROUND: Assessing the histopathological degree of liver damage is essential to the routine care of patients with chronic hepatitis C virus (HCV) infection. Several scoring systems have been proposed in attempts to standardize the histological assessment. One scoring system has been proposed by Ishak et al. Although widely endorsed, its interobserver reliability has not been evaluated. METHODS: 95 liver biopsies from patients with chronic HCV infection were scored by three independent observers. Interface hepatitis, confluent necrosis, focal necrosis, portal inflammation, and fibrosis were assessed. RESULTS: Confluent necrosis, which is more common in acute hepatitis, was not seen in any biopsy. For each of the remaining variables of inflammation (periportal hepatitis, focal necrosis, and portal inflammation) we found agreement in 95-96% for all three observers. Kappa scores ranged from 0.11 to 0.41 and weighted kappa scores from 0.18 to 0.53. For staging we noted 84% agreement, kappa scores of 0.26-0.47, and weighted kappa scores of 0.57-0.69. CONCLUSION: The Ishak system is associated with good interobserver reliability if a deviance of one categorical level in each variable of the system is accepted as agreement. Compared to the Knodell system it provides more detailed information but is less reliable regarding fibrosis.

Functional role of hepatitis C virus chimeric glycoproteins in the infectivity of pseudotyped virus.

The putative envelope glycoproteins of hepatitis C virus (HCV) likely play an important role in the initiation of viral infection. Available information suggests that the genomic regions encoding the putative envelope glycoproteins, when expressed as recombinant proteins in mammalian cells, largely accumulate in the endoplasmic reticulum. In this study, genomic regions which include the putative ectodomain of the E1 (amino acids 174 to 359) and E2 (amino acids 371 to 742) glycoproteins were appended to the transmembrane domain and cytoplasmic tail of vesicular stomatitis virus (VSV) G protein. This provided a membrane anchor signal and the VSV incorporation signal at the carboxy termini of the E1 and E2 glycoproteins. The chimeric gene constructs exhibited expression of the recombinant proteins on the cell surface in a transient expression assay. When infected with a temperature-sensitive VSV mutant (ts045) and grown at the nonpermissive temperature (40.5 degrees C), cells transiently expressing the E1 or E2 chimeric glycoprotein generated VSV/HCV pseudotyped virus. The resulting pseudotyped virus generated from E1 or E2 surprisingly exhibited the ability to infect mammalian cells and sera derived from chimpanzees immunized with the homologous HCV envelope glycoproteins neutralized pseudotyped virus infectivity. Results from this study suggested a potential functional role for both the E1 and E2 glycoproteins in the infectivity of VSV/HCV pseudotyped virus in mammalian cells. These observations further suggest the importance of using both viral glycoproteins in a candidate subunit vaccine and the potential for using a VSV/HCV pseudotyped virus to determine HCV neutralizing antibodies.

Hepatitis C virus core protein cooperates with ras and transforms primary rat embryo fibroblasts to tumorigenic phenotype.

We have previously demonstrated that hepatitis C virus (HCV) core protein regulates cellular protooncogenes at the transcriptional level; this observation implicates core protein in the alteration of normal hepatocyte growth. In the present study, the transforming potential of the HCV core gene was investigated by using primary rat embryo fibroblast (REF) cells which were transfected with or without cooperative oncogenes. Integration of the HCV core gene resulted in expression of the viral protein in REF stable transformants. REF cells cotransfected with HCV core and H-ras genes became transformed and exhibited rapid proliferation, anchor-independent growth, and tumor formation in athymic nude mice. Results from these studies suggest that the core protein plays an important role in the regulation of HCV-infected cell growth and in the transformation to tumorigenic phenotype. These observations suggest a possible mechanism for this viral protein in the pathogenesis of hepatocellular carcinoma in HCV-infected humans.

Immune responses to plasmid DNA encoding the hepatitis C virus core protein.

Hepatitis C virus (HCV) is a major causative agent of parenterally transmitted non-A, non-B hepatitis. The genomic region encoding the virion-associated core protein is relatively conserved among HCV strains. To generate a DNA vaccine capable of expressing the HCV core protein, the genomic region encoding amino acid residues 1 to 191 of the HCV-1 strain was amplified and cloned into an eukaryotic expression vector. Intramuscular inoculation of recombinant plasmid DNA into BALB/c mice (H-2d) generated core-specific antibody responses, lymphoproliferative responses, and cytotoxic T-lymphocyte activity. Our results suggest that the HCV core polynucleotide warrants further investigation as a potential vaccine against HCV infection.

Transcriptional regulation of cellular and viral promoters by the hepatitis C virus core protein.

The genomic region encoding the hepatitis C virus (HCV) core protein was cloned into a mammalian expression vector to study its role on the transcriptional regulation of cellular proto-oncogene and viral promoters. Using a transient transfection assay in human hepatocellular carcinoma (HepG2) cells, we demonstrate that the HCV core protein activates the human c-myc, Rous sarcoma virus long terminal repeat (LTR), and simian virus 40 (SV40) early promoters; and suppresses the c-fos promoter and human immunodeficiency virus type 1 (HIV-1) LTR activity. The transcriptional regulation of cellular proto-oncogenes by the HCV core protein suggests possible involvement of the core protein in the deregulation of normal hepatocyte growth and hepatocarcinogenesis.

Peptide immunogen mimicry of putative E1 glycoprotein-specific epitopes in hepatitis C virus.

Hepatitis C virus (HCV) accounts for most cases of acute and chronic non-A and non-B hepatitis with serious consequences that may lead to hepatocellular carcinoma. The putative envelope glycoproteins (E1 and E2) of HCV probably play a role in the pathophysiology of the virus. In order to map the immunodominant domains of the E1 glycoprotein, two epitopes from amino acid residues 210 to 223 (P1) and 315 to 327 (P2) were predicted from the HCV sequence. Immunization of mice with the synthetic peptides conjugated to bovine serum albumin induced an antibody response, and the antisera immunoprecipitated the E1 glycoprotein (approximately 33 kDa) of HCV expressed by recombinant vaccinia virus. A panel of HCV-infected human sera was also tested with the synthetic peptides by enzyme-linked immunosorbent assay for epitope-specific responses. Of 38 infected serum samples, 35 (92.1%) demonstrated a spectrum of reactivity to the P2 peptide. On the other hand, only 17 of 38 (44.7%) serum samples were reactive to the P1 peptide. Strains of HCV exhibit a striking genomic diversity. The predicted P1 epitope showed localization in the sequence-variable region, and the P2 epitope localized in a highly conserved domain. Results from this study suggest that the E1 glycoprotein of HCV contains at least two potential antigenic epitopes. Synthetic peptides corresponding to these epitopes and antisera to these peptides may serve as the monospecific immunological reagents to further determine the role of E1 glycoprotein in HCV infection.

Delayed treatment of pulmonary blastomycosis causing vertebral osteomyelitis, paraspinal abscess, and spinal cord compression.

A 36-year-old woman with gallbladder disease had an incidental finding of asymptomatic cavitary lung infection with Blastomyces dermatitidis. No treatment was given initially, and 2 months later she presented with vertebral osteomyelitis, paraspinal abscess, and spinal cord compression due to dissemination of the fungus. The patient recovered following surgical debridement and treatment with 1 g of amphotericin B, followed by itraconazole 400 mg QD for 6 months. In spite of previous reports of the self limiting nature of primary pulmonary blastomycosis in the normal host, antifungal therapy may be needed in cases that do not resolve spontaneously within a short period of time, or if transient immunosuppression may be anticipated as may occur following surgery or after acquisition of other infections.

Evaluation of QuickVue, a rapid enzyme immunoassay test for the detection of serum antibodies to Helicobacter pylori.

QuickVue is an enzyme immunoassay test for qualitative detection of serum immunoglobulin-G antibodies to Helicobacter pylori. We evaluated its ability to predict infection by H. pylori in 100 adult and 49 pediatric patients referred for gastric endoscopy. A patient was defined as infected with H. pylori if either culture or histology was positive. Of the 100 adult patients, 64 had H. pylori infection and QuickVue correctly identified 59 of the 64. Of 36 H. pylori-negative patients, 20 were correctly identified as negative by the test. In this sample of patients, QuickVue had a sensitivity of 92% and a specificity of 56%. In the 49 pediatric patients, QuickVue correctly identified nine of 11 infected cases and 34 of 38 noninfected patients. In this group, the sensitivity was 82% and the specificity was 89%. Overall the test had a sensitivity of 91% and a specificity of 73%. The positive predictive value was 77% and the negative predictive value was 89%.