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PubMed2003

Impact of HCV 3.0 EIA relative to HCV 2.0 EIA on blood-donor screening.

BACKGROUND: In 1996, the Ortho HCV Version 3.0 ELISA Test System (HCV 3.0 EIA) was licensed in the United States for donor screening but was neither mandated nor universally implemented. Data from two studies comparing the differential performance of HCV 3.0 EIA and HCV 2.0 EIA are presented. The first study evaluated the differential performance in a cross-section of screened whole-blood donors after implementation of HCV 3.0 EIA; the second study evaluated the differential performance of HCV 3.0 EIA in plasma donors acutely infected with HCV, identified during routine Abbott HCV 2.0 EIA and HCV NAT (using Roche Ampliscreen plate assay) donor screening. STUDY DESIGN AND METHODS: The first study evaluated HCV 3.0 EIA repeat-reactive donations from four US blood centers, identified during the first 5 months of HCV 3.0 EIA implementation. HCV EIA repeat-reactive donations confirmed by RIBA HCV 3.0 SIA were retested using both Ortho HCV Version 2.0 ELISA Test System and Abbott HCV 2.0 EIA. All EIA-discordant donations were tested by polymerase chain reaction (PCR). In the second study, Abbott HCV 2.0 EIA-nonreactive, HCV PCR-positive donors were enrolled in a follow-up study in which the index and follow-up samples were re-evaluated by HCV 3.0 EIA. RESULTS: In the first study, of 292,459 donations, 501 (0.17%) confirmed HCV 3.0 EIA-reactive donations were identified; 15 (0.005%) were nonreactive by Ortho HCV 2.0 EIA and were all HCV RNA negative. In the second study, Ortho HCV 3.0 EIA retesting of Abbott HCV 2.0 EIA-nonreactive, RNA-positive index donations identified 16 (23%) as 3.0 EIA reactive. In 42 panels with a discordant time of seroconversion, HCV 3.0 EIA sero-conversion preceded HCV 2.0 EIA in all cases (p < 0.001). Two donors with HCV 3.0 EIA-reactive index donations never seroconverted by HCV 2.0 EIA during 160 to 180 days of follow-up. CONCLUSION: These studies demonstrate that HCV 3.0 EIA compared to HCV 2.0 EIA can better detect 1) remote nonviremic HCV infections, 2) acute infection, and 3) HCV antibodies in cases of atypical seroconversion.

Blood Donors↗

PubMed2005

Novel assay using total hepatitis C virus (HCV) core antigen quantification for diagnosis of HCV infection in dialysis patients.

Dialysis patients remain a high-risk group for hepatitis C virus (HCV) infection. The current diagnosis of HCV infection among dialysis patients includes serological assays and nucleic acid amplification technology (NAT) for assessing serum anti-HCV antibody and HCV viremia, respectively. However, current NAT techniques are expensive and labor-intensive and often lack standardization. An assay prototype designed to detect and quantify total HCV core antigen (total HCV core Ag) protein in serum and plasma in the presence or absence of anti-HCV antibodies has been recently developed. A comparison between a total anti-HCV core Ag enzyme-linked immunosorbent assay (ELISA) and a quantitative HCV RNA assay based on reverse transcription-PCR (RT-PCR) (Amplicor HCV Monitor test) was performed using a large (n = 305) cohort of ELISA HCV 3.0 HCV-negative and -positive patients on maintenance dialysis. The concentrations of HCV core Ag and HCV RNA levels (measured by RT-PCR) were significantly correlated (r = 0.471, P = 0.0001) over a wide range of HCV RNA levels and were maintained among different HCV genotypes (HCV genotype 1, r = 0.862, P = 0.0001; HCV genotype 2, r = 0.691, P = 0.0001). We estimated that 1 pg of total HCV core Ag per ml is equivalent to approximately 19.952 IU of HCV RNA per ml, even if the wide range in the ratio of core Ag to HCV RNA (95% confidence intervals, 2.8 x 10(3) to 1.6 x 10(5) IU/ml) precluded definitive conclusions. In summary, total HCV core Ag proved to be useful for performing HCV RNA measurement among dialysis patients in routine laboratories without the need for special equipment or training. The present study supports the use of the total anti-HCV core Ag ELISA for assessing viral load among dialysis patients with HCV infection.

Aged↗

PubMed2004

Acute hepatitis C virus seroconversion in a Scottish blood donor: HCV antigen is not comparable with HCV nucleic acid amplification technology screening.

BACKGROUND AND OBJECTIVES: This study was conducted to analyse the usefulness of hepatitis C virus (HCV) core antigen tests for the confirmation of HCV infection in a donor presenting as nucleic acid amplification technology (NAT) positive but negative for antibodies to HCV (anti-HCV). MATERIALS AND METHODS: Blood donations were screened, in parallel, for anti-HCV using the Abbott PRISM HCV Chemiluminescent immunoassay (ChLIA) and an 'in-house' HCV NAT (pools of up to 95 donations). An HCV NAT-positive antibody-negative donor was identified. Twelve follow-up samples were obtained and tested with various HCV antigen (including the recently marketed Trak-C second-generation assay) and HCV antibody assays. RESULTS: The single HCV NAT-positive, antibody-negative donation was identified from 1 117 681 donations screened in the 4-year period, July 1999 to June 2003. The index donation was positive by Ortho HCV core antigen enzyme immunoassay (EIA) and Ortho Trak-C (second-generation HCV core antigen EIA). An archive sample, taken 127 days prior to the index donation, was negative for all HCV markers. Subsequent samples demonstrated a loss of reactivity in the Ortho HCV core antigen EIA and reduced activity in the Ortho Trak-C until day 69. Immunoblot (Ortho RIBA-3) and HCV PRISM became positive on day 62, whilst Ortho HCV ELISA was not positive until day 132 or Biorad HCV ELISA until day 160. An alternative immunoblot (Innogenetics Innolia III) was positive from day 55. RNA levels fluctuated considerably during the follow-up period, being completely undetectable by routine screening methods at the time-point around seroconversion; subsequently, antibody was detected using all assays investigated. CONCLUSIONS: This HCV-converting blood donor provided a unique panel of samples for using to assess current (and future) HCV assay systems. The overall test results led to the conclusion that individual HCV antigen testing should not be considered as equivalent to HCV NAT minipool screening. Trak-C antigen testing may be considered as a suitable confirmatory assay for isolated HCV NAT reactivity.

Acute Disease↗

PubMed2002

Analysis of HCV-immunoglobulin isotype complexes provide new insights into antibody response to HCV.

Hepatitis C virus (HCV) is known for its ability to establish persistent infection and cause chronic hepatitis in most infected individuals. The antibody response to HCV in HCV-circulating immune complexes (CIC) is unknown. In the present study, we have characterized distinct changes in patterns of HCV-immunoglobulin (Ig) constituents with disease category, viral mutation and clinical markers. The number of samples positive for single HCV-Ig, HCV-IgG and HCV-IgA, HCV-IgM and HCV-IgA, HCV-IgM and HCV-IgG, HCV-IgM, HCV-IgG and HCV-IgA in 47 samples tested were 8 (17%), 1 (2.1%), 9 (19.1%), 4 (8.5%) and 17 (36.2%), respectively. The occurrence of HCV-IgM and HCV-IgA in combination of two isotypes of HCV-Ig became predominant. These results show that defective IgG in HCV-CIC may contribute to long-term viremia. Further analysis indicated that the frequency of HCV RNA/IgA-CIC in the abnormal aspartic aminotransferase (AST) group was significantly higher than that of the normal AST group, and HCV RNA/IgA-CIC frequency in the abnormal alanine aminotransferase (ALT) group was slightly higher than that in the normal ALT group. IgA complexes may reflect the damage degree of liver function during the course of HCV infection. We also found that there were more mutations in supernatant than in other constituents from single-strand conformation polymorphism (SSCP) analysis. Our results suggest that Ig-complexed virions and free virions may have different biological consequences, with the latter being elusive to immunological elimination. The findings in this study may provide some new insights into antibody response to HCV.

Adolescent↗

PubMed2003

A new HCV core antigen assay based on disassociation of immune complexes: an alternative to molecular biology in the diagnosis of early HCV infection.

BACKGROUND: An EIA based on immune complex disassociation of nucleocapsid proteins of HCV has been developed to detect and quantify HCV core antigen. STUDY DESIGN AND METHODS: To evaluate whether this new assay (trak-C, Ortho Clinical Diagnostics) could be an alternative to NAT during the window period, its sensitivity in this context was assessed, and its performance was compared with that of a first-generation HCV core antigen assay dedicated to the blood screening (HCV core antigen ELISA). Studied populations included nine HCV RNA-positive, HCV antibody-negative blood donors and 23 hemodialysis patients who underwent an HCV seroconversion. From these individuals, 81 samples (23 HCV RNA-negative and 58 HCV RNA-positive) sequentially collected during the phase before seroconversion were tested. RESULTS: The nine blood donor samples were positive for the presence of HCV core antigen by the trak-C, and 6 of 8 tested were positive for the presence of HCV core antigen by blood screening ELISA. In the hemodialysis cohort, the 23 HCV RNA-negative samples were negative with the two HCV core antigen assays. Among the 58 HCV RNA-positive samples, 46 of 57 (80.7%) tested were positive for the presence of HCV core antigen with the blood screening assay, and 57 of 58 (98.2%) were positive for the presence of HCV core antigen with the trak-C. The mean delays in detecting HCV infection between trak-C and the appearance of HCV antibodies, between HCV RNA testing and trak-C, and between trak-C and HCV core antigen ELISA were 58.2, 0.24, and 3.33 days, respectively. CONCLUSION: Trak-C was more sensitive than the blood screening assay and had similar performance to HCV RNA assay in the window period. Trak-C could constitute an alternative to NAT for the diagnosis of HCV infection during the window period, especially when molecular biology procedures cannot be implemented.

Antigen-Antibody Complex↗

PubMed2005

Role of hepatitis C virus (HCV) viremia and HCV genotype in the immune recovery from highly active antiretroviral therapy in a cohort of antiretroviral-naive HIV-infected individuals.

BACKGROUND: The roles of hepatitis C virus (HCV) viremia and HCV genotype in the immune response to highly active antiretroviral therapy (HAART) are poorly understood. Our aim was to assess the CD4+ cell count recovery after HAART in human immunodeficiency virus (HIV)-infected patients with HCV viremia and HIV-infected patients who tested negative for HCV antibody (HCV-Ab). We also aimed to assess whether the response to HAART in these patients varied according to HCV genotype. METHODS: The analysis focused on 1219 HCV-Ab-negative patients and 284 HCV-viremic patients from a cohort of HIV-infected subjects that includes persons who were antiretroviral naive before initiating HAART after cohort enrollment. HCV RNA load and HCV genotype were determined in plasma specimens obtained and stored during the 6-month period preceding the initiation of HAART. RESULTS: The chance of achieving a CD4+ cell count increase of > or = 100 cells/microL from the pre-HAART level tended to be poorer in HCV-viremic patients than in patients who tested negative for HCV-Ab (adjusted relative hazard [RH], 0.82; 95% confidence interval [CI], 0.66-1.01; P = .06). In contrast, a comparison of patients who had a HCV RNA load >1 x 10(6) IU/mL with patients who had a HCV RNA load of 5-1 x 10(6) IU/mL revealed no significant association between HCV RNA load and achievement of an increased CD4+ cell count (adjusted RH, 0.97; 95% CI, 0.75-1.27; P = .83). There was no clear association between HCV genotype and the probability of achieving a CD4+ cell count increase. CONCLUSIONS: An association between the presence of HCV-Ab and immune reconstitution after HAART has been shown elsewhere. Results of our large, prospective study support a direct role of HCV viremia in the CD4+ cell count response to HAART. Moreover, our results underline the fact that, in individuals coinfected with HIV and HCV, the goal of treating HCV infection is to eradicate HCV, to both slow the rate of HCV progression and limit potential interference with the response to HAART.

Adolescent↗

PubMed1996

Significance of anti-E2 in the diagnosis of HCV infection in patients on maintenance hemodialysis: anti-E2 is frequently detected among anti-HCV antibody-negative patients.

A routine screening test used in the diagnosis of hepatitis C virus (HCV) infection is the anti-HCV antibody (anti-HCV) test containing core, NS3, NS4, and NS5 antigens of HCV. When HCV infection occurs in immunocompromised hosts, antibody formation against core, NS3, or NS4 antigens may be weak in the presence of HCV viremia and cannot be detected by routine anti-HCV tests. This study proposed that in immunocompromised hosts such as patients with chronic renal failure (whose capacity to form antibodies is diminished), antibody formation against the E2 region would be preserved, because the E2/NS1 region of HCV is strongly immunogenic. The aim of this study is to evaluate the significance of anti-E2 in the diagnosis of HCV infection among patients on maintenance hemodialysis who are anti-HCV-negative, using a conventional third-generation enzyme immunoassay (EIA) kit. The E2/NS1 gene of HCV encoding the amino acid sequence 388-664 was molecularly cloned into a vector containing an SV 40 promotor and was expressed in Chinese Hamster ovary cells. Using this E2 protein, the anti-E2 test was performed by EIA on 100 patients on maintenance hemodialysis, and on 50 patients with chronic hepatitis C who were anti-HCV-positive, to evaluate the antigenecity of the E2 protein. Of the 100 hemodialysis patients, 15 (15.0%) tested anti-HCV-positive using a third generation anti-HCV ELISA kit. Of the 85 patients who tested negative for anti-HCV, nine (10.6%) were anti-E2-positive and six (66.7%) of these anti-E2 positive patients showed HCV RNA viremia by HCV reverse transcription-polymerase chain reaction. Fourty-two (84.0%) of 50 patients with chronic hepatitis C were anti-E2-positive. As a control group, we tested for anti-E2 among 30 blood donors who were anti-HCV-negative, and also among 85 patients with hepatocellular carcinoma who were anti-HCV-negative, but in both groups, none (0%) was anti-E2-positive. In conclusion, these data suggest that the E2 protein of HCV should be included in a diagnostic anti-HCV kit for the detection of HCV infection in immunocompromised patients.

Animals↗

PubMed2003

Mix-infections with different genotypes of HCV and with HCV plus other hepatitis viruses in patients with hepatitis C in China.

AIM: Clinical therapy and prognosis in HCV infections are not good, and mix-infections with different HCV genotypes or quasispecies and mix-infections with HCV plus other hepatitis viruses are important concerns worldwide. The present report describes the sequence diversity and genotying of the 5'NCR of HCV isolates from hepatitis patients mix-infected with different HCV genotypes or variants, and the conditions of mix-infections with HCV plus other hepatitis viruses, providing important diagnostic and prognostic information for more effective treatment of HCV infections. METHODS: The 5' non-coding region (5'NCR) of HCV was isolated from the patients sera and sequenced, and sequence variability and genotypes of HCV were defined by nucleotide sequence alignment and phylogenetic analysis, and the patients mix-infected with HCV plus other hepatitis viruses were analyzed. The conditions and clinical significance of mix-infections with HCV plus other hepatitis viruses were further studied. RESULTS: Twenty-four out of 43 patients with chronic hepatitis C were defined as mix-infected with different genotypes of HCV. Among these 24 patients, 9 were mix-infected with genotype 1 and 3, 7 with different variants of genotype 1, 2 with different variants of genotype 2, 6 with different variants of genotype 3. No patients were found mix-infected with genotype 1 and 2 or with genotype 2 and 3. The clinical virological analysis of 60 patients mix-infected with HCV plus other hepatitis viruses showed that 45.0 % of the patients were mix-infected with HCV plus HAV, 61.7 % with HCV plus HBV, 6.7 % with HCV plus HDV/HBV, 8.4 % with HCV plus HEV, 3.3 % with HCV plus HGV. Infections with HCV plus other hepatitis viruses may exacerbate the pathological lesion of the liver. CONCLUSION: The findings in the present study imply that mix-infections with different HCV genotypes and mix-infections with HCV plus other hepatitis viruses were relatively high in Yunnan, China, providing important diagnostic and prognostic information for more effective treatment of HCV infections.

5' Untranslated Regions↗

PubMed2003

Anti-HCV and HCV-RNA prevalence and clinical correlations in cases with non-Hodgkin's lymphoma.

Hepatitis C virus (HCV) is an RNA virus in the Flaviviridae family. It displays lymphotropism in addition to hepatotropism and extrahepatic manifestations are very well known. There are many studies showing an association between HCV infection and non-Hodgkin's lymphomas (NHL). In this study the evidence for HCV infection was studied in cases with NHL. To this end, anti-HCV antibody and HCV-RNA were screened in serum samples of cases with NHL using third-generation ELISA and RT-PCR. Anti-HCV antibody was studied in 223 patients and was found to be positive in 18 cases (8.1%). Anti-HCV antibody positivity was compared with our blood bank/blood donor population. There was an important increased risk of HCV infection--the common odds ratio was 34.56 and corrected odds ratio was 19.07. HCV-RNA was studied in 67 of 223 serum samples. HCV-RNA was found to be positive in 21 of 67 samples (31.3%). When compared with clinico-demographic parameters for anti-HCV and HCV-RNA, including age, nodal status, and grade (in evaluable cases), except age in cases with or without HCV-RNA, we did not find an important correlation with HCV status and clinical findings (P=0.155; 0.442; 0.288 for anti-HCV and 0.027; 0,558; 0.126, respectively). These results suggest that HCV infection may be an important risk factor for lymphomagenesis and HCV-RNA is more useful for the detection of HCV infection in these immunosuppressed cases. Simultaneous detection of anti-HCV and HCV-RNA will be more informative in this population.

Adolescent↗

PubMed2002

Performance of the New Bayer VERSANT HCV RNA 3.0 assay for quantitation of hepatitis C virus RNA in plasma and serum: conversion to international units and comparison with the Roche COBAS Amplicor HCV Monitor, Version 2.0, assay.

We have evaluated the VERSANT HCV RNA 3.0. Assay (HCV 3.0 bDNA assay) (Bayer Diagnostics, Berkeley, Calif.), which is an improved signal amplification procedure for the HCV 2.0 bDNA assay for the quantitation of hepatitis C virus (HCV) RNA in serum or plasma of HCV-infected individuals. The HCV 3.0 bDNA assay has a linear dynamic range of 2.5 x 10(3) to 4.0 x 10(7) HCV RNA copies per ml (c/ml). The performance of the HCV 3.0 bDNA assay was evaluated using three different test panels. An overall specificity of 96.8% relative to the detection limit of the HCV 3.0 bDNA assay was found. The intra- and interrun reproducibilities for both the dilution panel and the NAP (AcroMetrix, Benicia, Calif.) panel were consistent with coefficients of variation of less than 9%. Quantitation with the HCV 3.0 bDNA assay was linear over the entire range of both panels (ranges of 4.4 x 10(3) to 3.5 x 10(6) c/ml and 5 x 10(3) to 2 x 10(6) IU/ml, respectively), with correlation coefficients of 0.999, slopes close to one, and intercepts close to zero. The regression equation indicated that 1 IU corresponded to about 4.8 copies of HCV RNA. A correlation coefficient of 0.941 was found for HCV RNA values (in international units per milliliter) obtained from the HCV 3.0 bDNA assay and the HCV Monitor version 2.0 assay (HCV Monitor 2.0 assay) (Roche Diagnostic Systems, Branchburg, N.J.). Quantitative results obtained close to the lower limit of the HCV 3.0 bDNA assay might imply that its lower limit should be reconsidered and raised, if necessary. It appeared that quantitation values obtained from the HCV Monitor 2.0 assay of between 5 x 10(2) and 10(5) IU/ml were in general higher than those obtained from the HCV 3.0 bDNA assay, whereas values obtained from the HCV Monitor 2.0 assay were underestimated for samples with HCV RNA levels above 10(5) IU/ml.

DNA, Viral↗

PubMed2002

Qualitative detection of hepatitis C virus RNA: comparison of analytical sensitivity, clinical performance, and workflow of the Cobas Amplicor HCV test version 2.0 and the HCV RNA transcription-mediated amplification qualitative assay.

The qualitative Cobas Amplicor hepatitis C virus (HCV) version 2.0 assay (HCV PCR) and the Bayer Reference Testing Laboratory HCV RNA transcription-mediated amplification assay (HCV TMA) were compared for analytical sensitivity, clinical performance, and workflow. Limits of detection were determined by testing dilutions of the World Health Organization HCV standard in replicates of 15 at concentrations of from 1.0 to 70 IU/ml. The limit of detection of the HCV PCR assay was calculated to be 45 IU/ml on initial testing and 32 IU/ml after resolution of gray zone results. The calculated limit of detection for HCV TMA was 6 IU/ml. To compare clinical performance, 300 specimens, grouped as follows, were evaluated: 112 samples that were indeterminate in an anti-HCV enzyme immunoassay (EIA) and for which HCV RNA was not detected by HCV PCR; 79 samples that were EIA positive and for which HCV RNA was not detected by HCV PCR; and 105 samples that were both EIA and HCV PCR positive. For these groups, interassay concordance ranged from 96.2% to 100%. In addition, three HCV PCR gray zone specimens and one neonatal specimen were also evaluated. A 64-sample run (full run, 91 specimens) required 5 h for testing by HCV TMA, whereas almost 8 h were required to test a full run of 22 specimens by HCV PCR. HCV TMA demonstrated excellent concordance with HCV PCR when clinical samples were tested. However, HCV TMA was more sensitive than HCV PCR, required less time for test result completion, and had a greater throughput.

Hepacivirus↗

PubMed2001

HCV-RNA positivity in peripheral blood mononuclear cells of patients with chronic HCV infection: does it really mean viral replication?

AIM: To analyze the association of HCV-RNA with peripheral blood mononuclear cells (PBMC) and to answer the question whether HCV-RNA positivity in PBMC is due to viral replication. METHODS: HCV-RNA was monitored in serum and PBMC preparations from 15 patients with chronic HCV infection before, during and after an IFN-alpha therapy using a nested RT/PCR technique. In a second approach, PBMC from healthy donors were incubated in HCV positive plasma. RESULTS: In the IFN-alpha responding patients,HCV-RNA disappeared first from total RNA preparations of PBMC and then from serum. In contrast, in relapsing patients, HCV-RNA reappeared first in serum and then in PBMC. A quantitative analysis of the HCV-RNA concentration in serum was performed before and after transition from detectable to non detectable HCV-RNA in PBMC-RNA and vice versa. When HCV-RNA was detectable in PBMC preparations, the HCV concentration in serum was significantly higher than the serum HCV-RNA concentration when HCV-RNA in PBMC was not detectable. Furthermore, at no time during the observation period was HCV specific RNA observed in PBMC, if HCV-RNA in serum was under the detection limit. Incubation of PBMC from healthy donors with several dilutions of HCV positive plasma for two hours showed a concentration dependent PCR positivity for HCV-RNA in reisolated PBMC. CONCLUSION: The detectability of HCV-RNA in total RNA from PBMC seems to depend on the HCV concentration in serum. Contamination or passive adsorption by circulating virus could be the reason for detection of HCV-RNA in PBMC preparations of chronically infected patients.

Adult↗

PubMed2000

Oral lichen planus: different clinical features in HCV-positive and HCV-negative patients.

BACKGROUND: Hepatitis C virus (HCV) infection induces variable dermatologic manifestations. OBJECTIVE: To determine whether differences exist in the clinical features and behavior of oral lichen planus (OLP) between HCV-positive (HCV+ve) and HCV-negative (HCV-ve) patients. METHODS: Two hundred and sixty three patients (156 women and 107 men), with a mean age of 55.5 years, with OLP (76 HCV+ve and 187 HCV-ve) were clinically evaluated. Previously, all local factors that could modify the clinical characteristics were removed and were monitored carefully following morphology. RESULTS: In both groups, the prevalent clinical form of OLP was the mixed form (33.1% in HCV-ve and 35.5% in HCV+ve patients), in which reticular-plaque lesions coexist with atrophic-erosive ones. The reticular form was more frequent in HCV+ve (25%) than in HCV-ve (18. 7%) patients, whereas plaque lesions were more prevalent in HCV-ve (15.5%) than in HCV+ve (5.2%) patients (P < 0.01, chi-squared test). There were no significant differences in the frequency of erosive (27.2% in HCV-ve and 27.6% in HCV+ve) and atrophic (5.3% in HCV-ve and 5.2% in HCV+ve) forms between the two groups. CONCLUSIONS: Our findings show that there were statistically significant differences between OLP-HCV-ve and OLP-HCV+ve groups for reticular and plaque clinical forms. These findings underline the importance of liver examination in all OLP patients, including cases with mild, asymptomatic keratotic forms of the disease.

Adult↗

PubMed1998

Absence of HCV viraemia in anti-HCV-negative haemodialysis patients.

BACKGROUND: Immunologic alterations have been reported in chronic haemodialysis (HD) patients. Some HD patients may have, therefore, an inability to produce detectable amounts of serum antibodies to hepatitis C virus (anti-HCV). Previous studies have shown the presence of HCV viraemia in anti-HCV-negative HD patients (ranging from 1 to 15%). However, the universal epidemiologic impact of these cases remains uncertain since there are conflicting results. In this context, we conducted a study in an attempt to investigate the presence of HCV viraemia among anti-HCV-negative HD patients in a well-defined geographic area of the northwestern part of Greece. METHODS: During a 6 month period, 81 anti-HCV-negative HD patients were tested twice for the presence of HCV RNA, using the reverse transcriptase polymerase chain reaction (RT-PCR) combined with a DNA enzyme immunoassay (DEIA). At the same time, periodic testing for anti-HCV by two commercially available third generation assays was done. In addition, 15 anti-HCV-positive HD patients and 20 non-HD patients with well established chronic HCV infection used as internal controls were tested for the presence of HCV RNA and anti-HCV. RESULTS: None of the anti-HCV-negative HD patients were shown to be viraemic by the combined RT-PCR and DEIA method. During the same time period, all remained anti-HCV negative by the third generation assays. By contrast, all the patients with known HCV-infection were positive by the two enzyme immunoassays, whereas 13 anti-HCV-positive HD patients (86.7%) and 18 non-HD patients (90%) were viraemic by RT-PCR. CONCLUSIONS: This study demonstrated that routine HCV RNA testing in anti-HCV-negative HD patients appears not to be necessary particularly when third generation assays are used for the detection of anti-HCV.

Adolescent↗

PubMedDate not supplied

[The presence of hepatitis C virus (HCV) infection in hemodialysis patients and determination of HCV genotype distribution].

The aim of this study was the investigation of hepatitis C virus (HCV) RNA by reverse transcriptase-polymerase chain reaction (RT-PCR), in hemodialysis patients in order to detect HCV infection, and the determination of virus genotypes in HCV positive patients. A total of 94 patients, 44 female and 50 male (mean age: 49 +/- 17 years old), who were included in hemodialysis program between 1987-1999 (0-13 years) in the Hemodialysis Units of Gazi University, School of Medicine and Ankara Etlik Hospital of Social Insurance Society, were enrolled in the study. Anti-HCV was found positive in 41 patients (43.6%), while HCV-RNA was positive in 36 patients (38.3%). Thirty three of the patients were positive for both anti-HCV and HCV-RNA, 8 were anti-HCV positive HCV-RNA negative, and 3 were anti-HCV negative HCV-RNA positive. HCV was genotyped by Restriction Fragment Length Polymorphism (RFLP) method in 36 HCV-RNA positive patients, and 28 yielded genotype 1b, and 8 showed genotype 1a pattern. PCR products from 5'UTR of HCV-RNA isolated from two patients were also sequenced to confirm the results of RFLP study. The rate of anti-HCV and HCV-RNA positivity was detected statistically higher in patients who exposed hemodialysis longer than 24 months, and in hemodialysis patients who had blood transfusion than the other groups. As a result, our findings supported that the periodic follow-up of HCV-RNA, in addition to anti-HCV would be useful for hemodialysis patients, and genotyping of HCV for the epidemiologic data.

Adolescent↗

PubMed2003

Suppression of HCV-specific T cells without differential hierarchy demonstrated ex vivo in persistent HCV infection.

Hepatitis C virus (HCV) has a high propensity for persistence. To better define the immunologic determinants of HCV clearance and persistence, we examined the circulating HCV-specific T-cell frequency, repertoire, and cytokine phenotype ex vivo in 24 HCV seropositive subjects (12 chronic, 12 recovered), using 361 overlapping peptides in 36 antigenic pools that span the entire HCV core, NS3-NS5. Consistent with T-cell-mediated control of HCV, the overall HCV-specific type-1 T-cell response was significantly greater in average frequency (0.24% vs. 0.04% circulating lymphocytes, P =.001) and scope (14/36 vs. 4/36 pools, P =.002) among the recovered than the chronic subjects, and the T-cell response correlated inversely with HCV titer among the chronic subjects (R = -0.51, P =.049). Although highly antigenic regions were identified throughout the HCV genome, there was no apparent difference in the overall HCV-specific T-cell repertoire or type-1/type-2 cytokine profile relative to outcome. Notably, HCV persistence was associated with a reversible CD4-mediated suppression of HCV-specific CD8 T cells and with higher frequency of CD4(+)CD25(+) regulatory T cells (7.3% chronic vs. 2.5% recovered, P =.002) that could directly suppress HCV-specific type-1 CD8 T cells ex vivo. In conclusion, we found that HCV persistence is associated with a global quantitative and functional suppression of HCV-specific T cells but not differential antigenic hierarchy or cytokine phenotype relative to HCV clearance. The high frequency of CD4(+)CD25(+) regulatory T cells and their suppression of HCV-specific CD8 T cells ex vivo suggests a novel role for regulatory T cells in HCV persistence.

Adult↗

PubMed1994

Hepatitis C virus infections in dialysis units: prevalence of HCV-RNA and antibodies to HCV.

HCV infection causes serious complications in dialysis patients that lead to problems in management of patients in dialysis units. Determination of HCV-RNA is at present essential for monitoring the course of HCV infection. Reports concerning HCV-RNA in dialysis patients are mostly from Asian dialysis units; therefore, an analysis of dialysis patients in Europe was undertaken. From 1515 patients 2630 blood samples were screened for HCV-RNA and anti-HCV. Two-thirds of patients positive in an anti-HCV test containing a mixture of three antigens (EIA-II, Ortho) were further analysed for antibodies against these individual antigens. From 523 patients multiple samples were tested. Related on dialysis units from which all the attending patients were tested, mean prevalence of HCV-RNA was 8.4%, of anti-HCV 13.2%. Concerning all plasma samples from dialysis patients sent to our laboratory for investigation of HCV-RNA and anti-HCV the prevalence of HCV-RNA was 21.9%, of anti-HCV 23.1%, HCV-RNA was present in 76% of anti-HCV positive patients and in 4.1% of anti-HCV negative patients (1.3% of single and 6.8% of multiple tested patients). Acute and chronic infections with self-limited, persistent or intermittent viraemia were observed with changes and fluctuations of both HCV markers. With the exception of differences in onset of antibody production in some patients following acute infections, there were no major differences of dialysis patients compared to patients without dialysis treatment as far as antibody spectrum and detectability of HCV-RNA were concerned.

Base Sequence↗

PubMed2000

The relationship between virological characteristics of hepatitis C virus (HCV) and reactivity to the regional specific proteins of HCV.

BACKGROUND: Although the polyproteins of hepatitis C virus(HCV) are processed and formed in nearly equimolar amounts, individual functional proteins have a discrepancy in their time of appearance following HCV infection and eliciting immune response. This study was conducted to compare the reactivity toward regional specific HCV protein in relation to virological characteristics, including HCV genotype and HCV replication. METHODS: Sera from forty-five patients with chronic HCV infection were analyzed through the experiments of the recombinant immunoblot assay(RIBA-2), HCV genotyping and HCV RNA quantitation. RESULTS: The frequencies of seropositivity to C22-3, C33C, C100-3 and 5-1-1 proteins were 91.1%, 91.1%, 64.4% and 53.3%, respectively, of all the patients, and thus the antibodies to C22-3 and C33C proteins were found more frequently (p < 0.05). The antibody responses between core or NS3 proteins and NS4 proteins showed more discrepancy in the HCC group than that in the CH group, implying a possibility of oncogenic potential of core or NS3 gene in hepatocarcinogenesis. The detection rate of antibodies to C22-3 and C33C, in accordance with serum HCV RNA levels, was significantly higher in highly viremic patients than that in low viremic patients (p < 0.05). Antibodies to C22-3, C33C, C100-3 and 5-1-1 were also found more frequently in patients with HCV genotype 1b, compared to those with HCV genotype 2a (p < 0.05). CONCLUSION: These results suggest that antibody detection of HCV may depend on the virological characteristics of HCV, the levels of HCV replication and HCV genotype and, therefore, HCV RNA detection using RT-PCR technique is essential for confirmatory diagnosis for HCV infection. Furthermore, the HCV core or NS3 Protein may play important role in hepatocarcinogenesis.

Adult↗