Early Hepatitis C Virus Infection Research Articles

Performance of ORTHO® HCV core antigen and trak‐C™ assays for detection of viraemia in pre‐seroconversion plasma and whole blood donors

Logistics and cost of nucleic acid amplification testing (NAT) screening preclude its current use in many developing countries. Development of hepatitis C virus (HCV) core antigen assays offer an alternative to NAT. We evaluated two specimen populations to assess the sensitivity, relative to NAT, of the HCV core antigen (HCVcAg) ELISA (enzyme-linked immunosorbent assay) test system and the trak-C assay: (1) plasma donor HCV NAT-conversion panels and (2) cross-sectional whole blood donor NAT yield specimens. Differential sensitivities among NAT (NGI; Chiron/Gen-Probe) and both HCVcAg assays (Ortho-Clinical Diagnostics, Rochester, NY) were evaluated using: (1) 102 serial ramp-up phase specimens from 37 plasma donor NAT-conversion panels (Alpha Therapeutic/BioClinical Partners); and (2) 42 cross-sectional whole blood donor NAT yield specimens (confirmed RNA positive, antibody negative) plus 54 NAT false-positive specimens (American Red Cross). Viral load among the plasma donor NAT-conversion panels at the cutoffs for HCVcAg and trak-C assays were 32 000 copies/ml (95% confidence interval [CI] 8000-120 000) and 8000 copies/ml (95% CI: 2200-28 000), respectively. The mean (95% CI) difference in window period reduction compared to routine mini-pool NAT screening (estimated sensitivity 100 copies/ml) was delayed 5.2 days (2.2-7.6 days) for HCVcAg assay and 3.8 days (2.1-5.5 days) for the trak-C assay. Among the 42 NAT yield specimens, the HCVcAg assay detected 31 (74%) as core antigen-positive while the trak-C assay detected 37 (88%) as core antigen-positive. Viral loads for the five specimens not detected by the trak-C HCVcAg assay ranged from 100 to 7770 copies/ml. All 54 NAT false-positive specimens were non-reactive on both HCV core antigen assays. These data indicate that the trak-C assay has sensitivity approaching routine mini-pool NAT screening for the detection of seronegative HCV infection. In the absence of routine NAT screening for early HCV infection, the use of an HCV core antigen assay should be considered.

Sensitivity of the Procleix HIV-1/HCV Assay for Detection of Human Immunodeficiency Virus Type 1 and Hepatitis C Virus RNA in a High-Risk Population

The Procleix HIV-1/HCV Assay is a high-throughput nucleic acid test for the simultaneous detection of human immunodeficiency virus type 1 (HIV-1) and hepatitis C virus (HCV) RNA during blood donor screening. This study evaluated the clinical sensitivity of the Procleix assay and assessed the assay's ability to identify HIV-1- and HCV-infected individuals undetected by standard serologic tests. Plasma samples were obtained prospectively from 539 individuals at high risk for HIV-1 and HCV infection at seven clinics affiliated with Johns Hopkins University. Samples were tested in the Procleix HIV-1/HCV Assay and, if reactive, were then tested in the Procleix HIV-1 and HCV discriminatory assays to differentiate the source of viral RNA positivity. Of these 539 subjects, 287 (53.2%) tested reactive in the Procleix HIV-1/HCV Assay. In discriminatory assay testing, 12 of 287 subjects (4.2%) were reactive for HIV-1 RNA only, 260 (90.6%) were reactive for HCV RNA only, and 11 (3.8%) were coinfected with HIV-1 and HCV. The clinical sensitivity for samples tested neat was 100% for HIV-1 and 99.3% for HCV. Three subjects with Procleix HCV reactive/seronegative results seroconverted upon follow-up and were confirmed as Procleix HCV yield cases. The Procleix HIV-1/HCV Assay is a highly sensitive test that detects ongoing and early HIV-1 and HCV infection in a significant number of subjects at high risk for these diseases. Confirmation of Procleix yield cases upon follow-up demonstrated the ability of the Procleix HIV-1/HCV Assay to detect the presence of HIV-1 and HCV in blood earlier than standard serologic tests.

Serum hepatitis C virus RNA levels and histologic findings in liver allografts with early recurrent hepatitis C.

Histopathologic features of early recurrent hepatitis C after orthotopic liver transplantation (OLTx) may be modified by immunosuppressive therapy or complicated by other conditions. Hepatitis C virus (HCV) RNA level usually increases after OLTx, but its correlation to histologic findings is not clear. To evaluate the histologic findings of early recurrent hepatitis C in liver allografts and its correlation to serum HCV RNA level. We studied 14 patients who underwent OLTx for chronic HCV infection. Thirty liver biopsy specimens and HCV RNA levels of 22 corresponding plasma samples obtained during the first 6 months following OLTx were analyzed. The control group (9 patients, 25 biopsy specimens) was chosen at random from patients with chronic liver disease other than HCV who were undergoing OLTx, and all tested negative for HCV RNA by polymerase chain reaction after OLTx. Statistically significant pathological features of early recurrent HCV infection were the number of acidophilic bodies, piecemeal necrosis, lymphocyte predominance in the portal tracts, and fibrous septum. These findings and histologic activity index scores increased with time after OLTx. The HCV RNA levels determined by branched DNA assay showed no significant correlation with histologic features. However, patients with higher histologic activity index scores tended to have higher RNA levels. Liver biopsy specimens are helpful for the diagnosis or confirmation of early recurrent hepatitis C in liver allografts, but serial biopsy specimens are sometimes required for definite diagnosis. The HCV RNA levels are usually higher in patients who display signs of more severe liver damage.

Hepatitis C Virus Infection Involves CD34+Hematopoietic Progenitor Cells in Hepatitis C Virus Chronic Carriers

AbstractAlthough hepatitis C virus (HCV) mainly affects hepatocytes, infection is widespread and involves immunologically privileged sites. Whether lymphoid cells represent further targets of early HCV infection, or whether other cells in the hematopoietic microenvironment may serve as a potential virus reservoir, is still unclear. We studied whether pluripotent hematopoietic CD34+ cells support productive HCV infection and can be used to establish an in vitro infection system for HCV. Six patients were selected as part of a cohort of HCV chronic carriers who developed a neoplastic disease. Reverse transcriptase-polymerase chain reaction (RT-PCR) and branched DNA signal amplification assays were used to detect and quantitate HCV RNA in extracted nucleic acids from purified bone marrow and peripheral blood CD34+ cells. Direct in situ RT-PCR, flow cytometry analysis, and immunocytochemistry were applied to demonstrate specific viral genomic sequences and structural and nonstructural virus-related proteins in intact cells. Results indicated that both positive and negative HCV RNA strands and viral proteins were present in CD34+ cells from all HCV-positive patients and in none of the controls. Additional experiments showed that a complete viral cycle took place in CD34+ cells in vitro. Spontaneous increases in viral titers indicated that virions were produced by infected hematopoietic progenitor cells. To further define the cellular tropism, we attempted to infect CD34+ cells in vitro. We were unable to demonstrate viral uptake by cells. These findings suggest that HCV replication can occur in the early differentiation stages of hematopoietic progenitor cells, and that they may be an important source of virus production.© 1998 by The American Society of Hematology.

Hepatitis C Virus Infection Involves CD34+Hematopoietic Progenitor Cells in Hepatitis C Virus Chronic Carriers

Although hepatitis C virus (HCV) mainly affects hepatocytes, infection is widespread and involves immunologically privileged sites. Whether lymphoid cells represent further targets of early HCV infection, or whether other cells in the hematopoietic microenvironment may serve as a potential virus reservoir, is still unclear. We studied whether pluripotent hematopoietic CD34+ cells support productive HCV infection and can be used to establish an in vitro infection system for HCV. Six patients were selected as part of a cohort of HCV chronic carriers who developed a neoplastic disease. Reverse transcriptase-polymerase chain reaction (RT-PCR) and branched DNA signal amplification assays were used to detect and quantitate HCV RNA in extracted nucleic acids from purified bone marrow and peripheral blood CD34+ cells. Direct in situ RT-PCR, flow cytometry analysis, and immunocytochemistry were applied to demonstrate specific viral genomic sequences and structural and nonstructural virus-related proteins in intact cells. Results indicated that both positive and negative HCV RNA strands and viral proteins were present in CD34+ cells from all HCV-positive patients and in none of the controls. Additional experiments showed that a complete viral cycle took place in CD34+ cells in vitro. Spontaneous increases in viral titers indicated that virions were produced by infected hematopoietic progenitor cells. To further define the cellular tropism, we attempted to infect CD34+ cells in vitro. We were unable to demonstrate viral uptake by cells. These findings suggest that HCV replication can occur in the early differentiation stages of hematopoietic progenitor cells, and that they may be an important source of virus production.© 1998 by The American Society of Hematology.

Comparison of histopathology in acute allograft rejection and recurrent hepatitis C infection after liver transplantation

Recurrent hepatitis C infection after orthotopic liver transplantation (OLT) is frequent and may occur as early as a few weeks postoperatively. Early histopathological features of recurrent hepatitis C virus (HCV) infection may be modified by immunosuppressive therapy and can be difficult to differentiate from acute allograft rejection (AAR). Thus, we retrospectively compared histopathological features of liver biopsy specimens from two carefully selected patient groups: one with unequivocal recurrent hepatitis C, the other with unequivocal AAR. Index biopsy specimens obtained at the time of the appearance of liver test abnormalities after OLT and all serial liver biopsy specimens (2 to 13 per patient) were assessed under code and scored semiquantitatively for 44 histopathological variables. The index biopsy specimens from patients with recurrent HCV infection and AAR index biopsies (AAR-Ib) differed significantly (P < .05) for 11 features (10 features were statistically associated with AAR and 1 with early recurrence of HCV infection). Statistically significant features associated with AAR included bile duct injury with overlapping nuclei, lymphocytic infiltrates and necrosis, endothelialitis, portal inflammatory infiltrates containing eosinophils and polymorphonuclear leukocytes, hepatocyte mitoses, and zone 3 canalicular cholestasis. In contrast, the only statistically significant feature associated with early recurrent HCV was sinusoidal dilatation. Stepwise discriminant analysis showed that the presence of eosinophils in the portal inflammatory infiltrate, bile duct necrosis, and bile duct lymphocytic infiltrates were independently associated with AAR. However, serial biopsy specimens from patients with recurrent HCV infection showed statistically significant progression in scores for portal inflammation, portal lymphoid aggregates, and lobular inflammation. We conclude that (1) multiple histopathological features are associated with AAR; (2) early recurrent HCV infection is characterized by elevated alanine aminotransferase levels, positive HCV RNA by polymerase chain reaction (PCR), and absence of diagnostic histopathological features; and (3) serial biopsies are needed to demonstrate progression of histopathological features of recurrent hepatitis C. (Liver Transpl Surg 1997 Jul;3(4):398-406)

Markers of Hepatitis C Infection among Hemodialysis Patients with Acute and Chronic Infection: Implications for Infection Control Strategies in Hemodialysis Units

To evaluate strategies for screening patients on hemodialysis (HD) for markers of acute and chronic hepatitis C virus (HCV) infection, we studied sixty-nine patients at a single center over a 36-month period. Serum samples were tested for alanine aminotransferase (ALT) levels, anti-HCV and HCV RNA at 3-4 month intervals. Anti-HCV was tested for by EIA1, EIA2, and RIBA2. HCV RNA was detected by polymerase chain reaction (PCR). In addition, IgM antibody to the c33 antigen of HCV was detected by an experimental EIA. Of the 43 HD patients at the start of the study, anti-HCV was detected by EIA1 in 13 (30%). All EIA1 positive patients and 14 (47%) of the 30 EIA1 negative patients tested positive by EIA2. Thus, at the start of the study 27 (63%) of 43 patients tested positive for anti-HCV by EIA2. The presence of anti-HCV among EIA2 positive patients was confirmed by RIBA2 in all patients. Based on the PCR results, the sensitivity, specificity, positive predictive value and negative predictive value for EIA1 were 48%, 100%, 53% and 100%, respectively, and for EIA2 were 100%, 100%, 100% and 100%, respectively. During follow-up, 26 EIA2 negative patients began HD in the unit. Of the 42 EIA2 negative patients, five (12%) seroconverted for anti-HCV during follow-up. All five patients with new HCV infection tested positive for HCV RNA three months prior to the detection of anti-HCV by EIA2.(ABSTRACT TRUNCATED AT 250 WORDS)

Detection of hepatitis C virus RNA in hemodialysis patients.

The clinical significance of the high prevalence of antibodies to hepatitis C virus (HCV) in dialysis patients remains undefined. In order to assess the relationship between seropositivity and potential infectivity, 63 patients undergoing maintenance hemodialysis were evaluated between April and May 1990. The mean duration of maintenance hemodialysis was 45 mo (range, 13 to 144). Eighty-two percent (52 of 63) had received blood transfusions, and 16% (10 of 63) had a history of iv drug abuse. Serum samples were analyzed by HCV-cDNA polymerase chain reaction; antibodies to HCV structural (core) and nonstructural regions NS3 and NS4 were determined by enzyme immunoassay. Specimens repeatedly reactive for anti-HCV and HCV-RNA-positive samples were tested by HCV MATRIX dot immunoblot assay and HBV-DNA PCR. Twenty-five percent (16 of 63) were anti-HCV-positive. Of the 16 anti-HCV-positive patients, HCV-RNA was detected in 5 (31%) with the NS3 primers and in 12 (75%) with 5'-noncoding primers. Among the anti-HCV-negative patients, HCV-RNA was detected in 2 (4.3%) of 47 patients. Eleven of the 18 patients with HCV infection (anti-HCV and/or HCV-RNA-positive) had evidence of additional present or past viral infections (human immunodeficiency virus and/or hepatitis B virus). In summary, HCV-RNA is present in at least 75% of anti-HCV-positive patients, suggesting that they may be infectious. The detection of HCV-RNA in anti-HCV-negative patients may indicate early or chronic HCV infection not detected by current antibody assays or the inability of these patients to mount or sustain a significant antibody response.