Peripheral mononuclear cells of haemophiliacs with chronic liver disease are infected with replicating hepatitis C virus

Human cell types important for hepatitis C virus replication in vivo and in vitro: old assertions and current evidence

Hepatitis C Virus (HCV) is a single stranded RNA virus which produces negative strand RNA as a replicative intermediate. We analyzed 75 RT-PCR studies that tested for negative strand HCV RNA in liver and other human tissues. 85% of the studies that investigated extrahepatic replication of HCV found one or more samples positive for replicative RNA. Studies using in situ hybridization, immunofluorescence, immunohistochemistry, and quasispecies analysis also demonstrated the presence of replicating HCV in various extrahepatic human tissues, and provide evidence that HCV replicates in macrophages, B cells, T cells, and other extrahepatic tissues. We also analyzed both short term and long term in vitro systems used to culture HCV. These systems vary in their purposes and methods, but long term culturing of HCV in B cells, T cells, and other cell types has been used to analyze replication. It is therefore now possible to study HIV-HCV co-infections and HCV replication in vitro.

Percutaneous liver biopsy in hemophiliac children with chronic hepatitis C virus infection

OBJECTIVE

To develop a protocol for safe performance of percutaneous liver biopsies in children with deficiency of factor VIII (n = 12) or IX (n = 2) and chronic hepatitis C virus infection.

PATIENTS AND METHODS

Liver biopsies were performed after administration of factor VIII or IX, before and 24 weeks after cessation of antiviral therapy. To define the optimal means of providing replacement therapy, 10 children were enrolled in a randomized crossover design study of bolus versus continuous factor VIII for performance of the liver biopsy. For the crossover study, all of the patients were given a loading dose of 50 +/- 5 IU recombinant factor (rF)VIII/kg; a minimum of factor VIII activity of > or = 80% 30 to 60 minutes following factor VIII infusion was required for liver biopsy. For the bolus protocol, rFVIII 25 to 50 IU/kg was given 6, 14, 24, 36, 48, and 60 hours after completion of the loading dose. For the continuous protocol, rFVIII was given 3 to 4 IU/kg per hour for 48 hours, followed by a bolus of 25 IU/kg at 60 hours. In patients with factor IX deficiency, a loading dose of 100 IU/kg was followed by a bolus of 50 IU/kg at 3, 15, 27, and 48 hours after the loading dose.

RESULTS

Twenty liver biopsies were performed in children with factor VIII deficiency without major complications. One of the 3 biopsies in the patients with factor IX deficiency was complicated by a hemoperitoneum. Midazolam and fentanyl were used in the first 8 patients. However, postbiopsy pain, presumably secondary to hematoma in 2 patients and hemoperitoneum in 1, prompted us to use ultrasound to locate a suitable biopsy site and to change to propofol; this allowed us to better immobilize the liver, to minimize postbiopsy bleeding. The subsequent 15 biopsies were well tolerated without postbiopsy pain or other complication.

CONCLUSIONS

Percutaneous liver biopsy in children with factor VIII deficiency can be safely performed using either bolus or continuous infusion of recombinant factor VIII. A brief general anesthetic and ultrasound guidance are recommended.

Detection of HCV-RNA in Cerumen of Chronically HCV-Infected Patients

OBJECTIVES/HYPOTHESIS

Viral hepatitis C is a worldwide public health problem. Hepatitis C virus is mainly transmitted by parenteral or percutaneous route. Nonparenteral transmission, such as through sexual activity, household contact, and vertical or perinatal exposure to body fluids or secretions, can occur, which has been studied before. Cerumen, however, has not been investigated for its ability to transmit hepatitis C virus. The aim of this study is to evaluate the importance of cerumen in transmission of hepatitis C virus infection.

STUDY DESIGN

This study was performed on 35 patients with confirmed chronic hepatitis C virus infection.

METHODS

Thirty-five cerumen specimens collected from the patients with hepatitis C virus RNA in their sera were prospectively analyzed for the presence of hepatitis C virus RNA by polymerase chain reaction.

RESULTS

None of the 35 cerumen specimens were positive for hepatitis C virus RNA.

CONCLUSION

This study showed that cerumen has no risk for transmission of hepatitis C virus infection, even in patients with high hepatitis C virus RNA serum levels; however, standard infection control precautions should be applied carefully in all examinations and surgical operations of the ears.

Association between hepatitis C infection and other infectious diseases: a case for targeted screening?

OBJECTIVE

Hepatitis C virus (HCV) shares risk factors and routes of transmission with several other infectious agents. However, the prevalence of comorbid infectious disorders among HCV-infected patients remains unknown. To analyze the association between HCV and several categories of infectious disorders, we carried out a case-control study using information from 172 hospitals contained in the computerized databases of the Department of Veterans Affairs.

METHODS

We identified all HCV-infected patients who were hospitalized during 1992-1999. For each case, four control subjects without HCV were randomly chosen from hospitalized patients and were matched with cases on the year of admission. The frequencies of several predefined infectious disease diagnoses were compared between cases and control subjects, and the strength of these associations were assessed in multivariable logistic regression analyses.

RESULTS

We identified 34,204 HCV-infected patients (cases) and 136,816 control subjects without HCV. Patients in the case group were younger (48.4 yr vs 59.8 yr), were more frequently nonwhite (38.5% vs 26.5%), and were more likely to have served in Vietnam (68.1% vs 33.0%); all p < 0.0001. Compared with control subjects, patients with HCV had a significantly higher prevalence of other blood-borne virus infections, including HIV (14.1% vs 3.0%) and hepatitis B (22.4% vs 0.7%); immunodeficiency-related infections, including cytomegalovirus (0.6% vs 0.2%), toxoplasmosis (0.3% vs 0.1%), cryptococcosis (0.4% vs 0.1%), and tuberculosis (3.3% vs 1.3%); sexually transmitted diseases, including gonococcus (0.5% vs 0.1%), chlamydia (1.6% vs 0.7%), syphilis (2.0% vs 0.6%), and genital herpes (1.0% vs 0.3%); and bacterial infection, including peritonitis, sepsis, endocarditis, cellulitis, and carbuncles (all p < 0.0001). After excluding potentially immunocompromised patients, including those with HIV, organ transplant, and cirrhosis, HCV remained significantly associated with CMV, cryptococcus, tuberculosis, and sexually transmitted diseases. Similar results were obtained when the analyses were restricted to Vietnam-era veterans.

CONCLUSIONS

Several infectious diseases are more common among HCV-infected patients compared with those without HCV infection. These findings support an approach of targeted screening for HCV among patients with these infectious diseases.

High viral load and mild liver injury in children with hemophilia compared with other children with chronic hepatitis C virus infection

BACKGROUND

In adults with hepatitis C virus (HCV) infection, the severity of liver disease may be influenced by the mode of transmission. The purpose of this study was to evaluate whether the mode of transmission affects liver injury and viral load in children with chronic HCV infection, independent of duration of infection and/or HCV genotype.

METHODS

Thirty-nine anti-HCV (EIA-2) positive patients, were divided into three groups: group 1, children with a history of blood transfusion (n = 9; age, 13.3+/-1.3 years), group 2, children with hemophilia (n = 19; age, 11.6+/-0.8 years); and group 3, children with maternal-fetal transmitted disease (n = 10; age, 4.7+/-1.1 years). Serum alanine aminotransferase, HCV viral load, HCV genotype, and liver histology were assessed.

RESULTS

Serum HCV viral load was higher in group 2 (4.27+/-1.0x10(6) copies/ml; p = 0.006) than in group 1 (0.73+/-0.3x10(6) copies/ml) and in group 3 (0.83+/-0.2x10(6) copies/ml). Conversely, group 2 had less severe liver injury compared with children of similar age in group 1 (p = 0.022). Despite a shorter duration of infection, group 3 had liver injury similar to that in group 1. Hepatitis C virus genotype did not influence the level of viremia or liver injury.

CONCLUSIONS

Although children with hemophilia exhibited a high HCV viral load, liver histopathology was less severe than in children who had acquired HCV by blood transfusion or maternal-fetal transmission. These observations support the need to investigate the role of host immune response rather than the virus per se in the pathogenesis of HCV infection in children.

Detection of hepatitis C virus RNA (HCV RNA) in amniotic fluid: a prospective study

BACKGROUND/AIMS

Mother-to-infant transmission of hepatitis C virus (HCV) has been reported, but the transmission route is unknown. The aim of our study was to detect HCV RNA in amniotic fluid of pregnant women seropositive for HCV.

METHODS

Twenty-two HCV seropositive women were included in the study (median age: 39 years). An amniocentesis was performed in all patients during the 4th month of pregnancy. Sixteen women also tested positive for HCV RNA in serum. The range of HCV RNA titers was 0.3 to 15.1x10(6) Eq/ml (Quantiplex HCV RNA 2.0 Assay, Chiron Diagnostics). Of these 16 viremic patients, four had an anterior placenta, ten had a posterior placenta and the position of the placenta was not determined in two cases. PCR (Amplicor HCV, Roche Diagnostics) was used to detect HCV RNA in the amniotic fluid. We also studied 11 HCV seronegative women as a control group.

RESULTS

In the viremic group (n = 16), HCV RNA was detected once in amniotic fluid. The positive specimen was collected from a patient with an HCV RNA serum value equal to 1.1x10(6) Eq/ml. The placenta was in an anterior position. A PCR inhibitor was detected in one case. No HCV RNA was detected in the amniotic fluid of six seropositive non-viremic patients, nor in the control group. Serum HCV RNA was negative in the ten children tested. The woman whose amniotic fluid contained HCV RNA was the mother of one of them.

CONCLUSIONS

HCV RNA detection in amniotic fluid is rarely positive. The anterior position of the placenta in the only positive detection cannot rule out contamination of the amniotic fluid during the transplacental amniocentesis.

Hepatitis C virus persistence in human hematopoietic cells injected into SCID mice

The issue of infection of peripheral blood mononuclear cells (PBMC) by the hepatitis C virus (HCV) has potentially important implications, but is still debated. We have used the severe combined immunodeficiency (SCID) mouse model to test for the persistence of HCV in PBMC. Hematopoietic cells isolated from 14 subjects infected by HCV were inoculated intraperitoneally into SCID mice. Serum and blood cell samples from these mice were obtained with a mean follow-up of 8 weeks. As controls, human fibroblasts and sheep PBMC, preincubated with a human HCV-positive serum, were inoculated concomitantly into mice and analyzed. HCV-RNA positive strands were detected in 7 of 26 serum samples and 8 of 26 cell fractions from SCID mice inoculated with HCV-positive PBMC, after 8 weeks of follow-up. In contrast, no HCV RNA was detectable in the 10 control mice. HCV-RNA negative strands were detected in only 2 of 10 tested samples from 2 mice, and both positive mice had been inoculated with PBMC from HCV-positive subjects with malignant hematopoietic syndrome. Our study offers strong evidence for the persistence of HCV infection in mononuclear cells. Our results are also consistent with a low rate of HCV multiplication. This SCID mouse model might therefore be useful in analyzing the mechanisms of HCV persistence in mononuclear cells.

Chronic viral hepatitis enhances the risk of infection but not acute rejection in renal transplant recipients

To assess the impact of chronic viral hepatitis on host immune response, we analyzed the incidence of acute rejection and the frequency of infections in 86 patients infected with hepatitis B and C viruses and had developed clinical evidence of chronic liver disease and 1283 control patients who were transplanted at our center during the same period, but had no evidence of chronic viral hepatitis. To compare the mean number of rejections and the mean number of infections between the two groups, we used multivariate linear regression analysis, which allowed us to adjust simultaneously for the effects of 10 other risk variables with potential impact on graft rejection and posttransplant infection. During a mean follow up of 5.3+/-5.2 years, 62% of hepatitis patients and 54% of control patients had experienced an acute rejection (P=NS). The mean rejections/patient in the hepatitis group was 1.3+/-0.14 versus 1.03+/-0.03 in control (P=NS). In the linear regression analysis, the number of acute rejections in the hepatitis group was 0.16 higher than in control (P=NS). With reference to infection, 84% of hepatitis patients experienced an infectious complication in the posttransplant period, compared with 75% in the control (P=0.05). The mean number of infections/patient was 5.7+/-0.73 in the hepatitis group compared with 3.9+/-0.14 in the control group (P=0.002). The linear regression model had shown that the hepatitis group had a relative increase of 1.18 infections/pt, compared with control. Of the different sites of infection, the hepatitis group had a significant increase in bloodstream (0.48+/-0.08 vs. 0.25+/-0.02) P=0.003; pulmonary (0.60+/-0.09 vs. 0.38+/-0.03) P=0.03; and CNS infections (0.08+/-0.03 vs. 0.02+/-0.004) P=0.05 compared with control. Among the different microorganisms causing infection, the hepatitis patients had a significant increase in gram negative bacterial infections compared with the control group (74% vs. 61%) P=0.04. Our data suggest that chronic viral hepatitis is associated with a significant increase in overall infections, and that of potentially fatal infections involving CNS, lungs and bloodstream. Since there is no significant increase in the rate of graft rejection, one could consider a cautious reduction in the doses of maintenance immunosuppressive agents in renal transplant patients with chronic viral hepatitis. The reduced immunosuppression may in turn lower the death rate from sepsis and progressive hepatic failure.

Specific detection of hepatitis C virus minus strand RNA in hematopoietic cells

The presence of hepatitis C virus (HCV) negative strand RNA in extrahepatic compartments based on PCR detection assays has been suggested in many reports with a very heterologous detection rate (from 0 to 100%). In this study, we have analyzed the presence of HCV negative strand in hepatic (liver biopsies, n = 20) and extrahepatic (sera, n = 32; PBMC, n = 26 and fresh bone marrow cells, n = 8) compartments from infected patients with three different reverse transcriptase (RT)-PCR-based assays using primers located in the 5' noncoding region, with or without a tag selected to display different viral loads (10(5)-3 x 10(7) genomic equivalent/ml or gram) and viral genotypes (n = 5). Using synthetic as well as biological templates, we could document extensive artifactual detection of negative strand RNA, due to self priming and mispriming events, even either 5' noncoding region primer pair was used, whereas both artifacts were dramatically reduced (mispriming) or eliminated (selfpriming) using CAP-based RT-PCR assay. Mispriming artifacts were directly correlated to the titer of positive strand RNA present in the sample. Using the CAP-PCR assay, the presence of HCV negative strand RNA was found in 75% of livers (16:20) and only 8% of PBMC, independent of the genotype involved, but could not be documented in sera (0:32) and fresh bone marrow cells (0:6). These findings suggest that caution regarding the type of RT-PCR assay used and the level of HCV positive strand RNA present in the biological sample analyzed has to be taken to avoid false identification of viral reservoirs. The findings suggest that hematopoietic peripheral cells can support HCV replication, although in a very limited number of carriers.