Detection of hepatitis C virus sequences in sera with controversial serology by nested polymerase chain reaction.

The specificity of first-generation enzyme-linked immunosorbent assays (ELIAs) for antibody detection in individuals with hepatitis C virus (HCV) infection has been questioned in some pathological situations. We observed a surprisingly high prevalence of anti-HCV antibodies in alcoholic patients, and thus, false-positive reactions in anti-HCV tests were strongly suspected. The introduction of new epitopes, particularly a core protein, C22 (second-generation tests), seems to increase the sensitivity of anti-HCV detection. In order to study the specificity of the second-generation tests, 60 serum samples from alcoholic patients found to be positive by the first-generation anti-HCV ELISA (Ortho) were reexamined by a second-generation anti-HCV enzyme immunoassay (Abbott) and a recombinant immunoblot assay (RIBA II; Chiron). Fifteen serum samples gave contradictory results when they were tested by the two assays. We performed nested polymerase chain reactions (PCRs) to confirm that the discrepancies that we observed could be due to the presence of low levels of anti-HCV antibodies, which were detected by a more sensitive test, or to unspecific positive reactions. Nested PCR revealed the presence of HCV RNA sequences in all anti-HCV-positive sera or sera that were weakly positive by ELISA. Anti-HCV positive by RIBA II was always correlated with the presence of viral RNA in serum, but HCV RNA was detected in RIBA II-negative sera. These results indicate that the specificity of the second-generation tests is an important improvement but that an HCV infection can still persist without detectable antibodies. PCR remains the reference assay to clear up controversial serology results and to detect HCV infection in patients with no anti-HCV-detectable immune response.     

Hepatitis C virus antibodies and hepatitis C virus RNA in Chinese blood donors determined by ELISA, recombinant immunoblot assay and polymerase chain reaction.

Antibodies to hepatitis C virus (anti-HCV) were determined in Chinese blood donors from the city of Wuhan by a second generation ELISA screening test and a confirmatory recombinant immunoblot assay (RIBA II). Two materials of 281 and 222 sera were sampled under similar conditions in 1989 and 1990, respectively. The first collection of sera was sent to Sweden in lyophilized form, the second directly as fresh unfrozen sera. A high proportion (7.1%) of the lyophilized sera reacted positively in the anti-HCV screening assay, but only seven (2.5%) were positive by the RIBA confirmatory test. In four of these sera HCV-RNA could be detected by polymerase chain reaction (PCR) analysis. In the second material of fresh sera six reacted positively in the screening anti-HCV ELISA, but only one was RIBA positive and four were RIBA indeterminate. None of these sera was positive for HCV-RNA. Thus, the overall prevalence of anti-HCV among the 503 Chinese blood donors, as identified by RIBA, was 1.6%, and of HCV-RNA by PCR 0.8%. The confirmed antibody prevalence is higher than reported from the Western world. Caution about using data from the screening ELISA only, especially if sera have been handled in an unorthodox way, is emphasized.     

Determination of hepatitis C virus genotypes among blood donors in Ahvaz,Iran

This study aims to determine the genotypes of hepatitis C virus (HCV) among blood donors at Ahvaz Blood Transfusion Centre. Blood samples were taken from 2376 blood donors -$$$ 1795 (75.54%) male and 581(24.45%) female -$$$ who referred to Ahvaz Blood Transfusion Centre during 2007-2008. Detection of anti-HCV antibody for all the donors was carried out by ELISA and the confirmatory RIBA tests. HCV RT-PCR followed by RFLP test was carried out for anti-HCV positive samples. Out of 2376 blood donors, only 55 (2.3%) male donors showed to be positive for HCV antibody by ELISA and RIBA tests out of which 45(1.8%) donors were positive for RT-PCR test. Female donors were negative for HCV antibody. The result of HCV genotyping by RFLP test showed 24 (53.3%) for 1a, 17 (37.7%) for 3a (α) and 4 (8.8%) for 3a (β) genotypes respectively. In conclusion, high prevalence of 53.3% HCV 1a genotype was observed among blood donors in Ahvaz city.     

Hepatitis C virus antibody prevalence among human immunodeficiency virus-1-infected individuals: Analysis with different test systems

Sera of 383 human immunodeficiency virus (HIV)-l-infected individuals from Frankfurt (Main)/Germany were assayed by two hepatitis C virus (HCV) screening tests (Abbott second generation, Ortho second generation). This population showed a prevalence for reactivity with both tests of 20.8% (80/383). Examination of all reactive sera (91/383) by a supplemental assay (Chiron RIBA 2) gave for 46 sera a positive, for 33 sera an indeterminate, and for 12 sera a negative result. Further analysis focussed on these RIBA 2-indeterminate and -negative samples. Analysis of the sera using an in-house Western blot with three different Escherichia coli-expressed HCV proteins revealed that none of the RIBA 2-nega-tive, but 24 of the 33 RIBA 2-indeterminate sera, including 3 of 4 c33c (NSS)-reactive samples, were reactive with a recombinant core protein. Twenty-one of 22 c22-3 (core) indeterminates stained the core antigen in the in-house Western blot and 3 of them in addition a NS5 moiety. HCV-polymerase chain reaction (PCR) was positive for 14 of the 24 RIBA 2 -indeterminate sera, but for none of the RIBA 2-negative or Western blot nonreactive samples. Discrepant results between the two screening tests could not be explained by differences in the antigen compositions (i.e., a NS3-NS4 moiety of 111 amino acids present in the Ortho enzyme-linked immunosor-bent assay (ELISA), not present in the Abbott or RIBA 2 assays). © 1994 Wiley-Liss, Inc.     

Coxsackie B virus infections in women with miscarriage

Serum samples from 1,765 consecutive Sardinian blood donors, negative for hepatitis B surface antigen (HBsAg) and for antibodies to human immunodeficiency virus (HIV) (anti-HIV), were evaluated for the presence of antibodies to hepatitis C virus (anti-HCV) by second-generation ELISA. Anti-HCV was detected in 25 (1.45%) of the 1,765 donors examined. Anti-HCV was found in 15 of the 1,690 (0.9%) donors with normal alanine aminotransferase (ALT) and in 10 of the 75 (13%) donors with elevated ALT (P < 0.0001). Of the 15 anti-HCV-positive donors with normal ALT, only five (33%) were confirmed to be positive by second-generation RIBA, six (40%) were indeterminate, while four (27%) were RIBA negative. HCV RNA, as detected by polymerase chain reaction (PCR) using a set of primers from the 5′-noncoding region, was found in six of the 15 (40%) donors with normal ALT, including five RIBA, positive and one indeterminant. Of the 10 anti-HCV-positive donors with elevated ALT, all were RIBA positive and eight (80%) had detectable HCV RNA. Thus, among ELISA-reactive donors, those with elevated ALT had a significantly higher probability of being positive for secondgeneration RIBA and HCV RNA compared to those with normal ALT levels (P = 0.028). None of the 65 donors with elevated ALT but negative for anti-HCV by ELISA had detectable serum HCV RNA, as compared to eight of 10 anti-HCV ELISApositive donors (P < 0.0001). However, although negative for HBsAg, 12 of the 65 (18%) had serum HBV DNA by PCR. This study demonstrates that the combined use of second-generation ELISA and RIBA anti-HCV assays is highly effective in identifying HCV infection, whereas the specificity of ELISA alone for the screening of blood donors with normal ALT values appears to be limited. In contrast, in donors with elevated ALT levels, there is a positive correlation between second-generation assays (ELISA and RIBA) and HCV viremia. The high proportion of inapparent HBV infection in blood donors with elevated ALT levels underlines the importance of this test for the prevention of transfusion-associated viral hepatitis.     

Improved diagnosis of chronic hepatitis C virus infection by detection of antibody to multiple epitopes: confirmation by antibody to synthetic oligopeptides.

Serum samples from 226 patients covering a wide spectrum of liver disease were tested for antibodies to hepatitis C virus (HCV) using both first and second generation enzyme linked immunosorbent assays. Selected sera were also tested by peptide immunoassays, by the four-antigen recombinant immunoblot assay (RIBA II), and for viral genome by the polymerase chain reaction. Antibody to c100-3 was detected in 61% of patients with chronic non-A, non-B (NANB) hepatitis and/or 46.5% with presumed NANB-related cirrhosis by the first generation test. These figures increased to 77% and 58% when antibodies to recombinant structural and non-structural HCV antigens were sought by the second generation assay. Supplemental testing against peptide Sp75 and Sp65/sp67 confirmed that reactivity of sera by second generation assays was due to antibodies to the additional structural and non-structural antigens. Samples negative by the first generation assay were not confirmed by the supplemental assay using peptides Sp75 and Sp65/Sp67. HCV RNA was detected in 60% of the anti-HCV positive sera tested, most of which were also RIBA II positive. Our findings confirm that the introduction of the structural and non-structural antigens, especially the putative nucleocapsid protein, improves sensitivity of detection of antibodies to HCV, and facilitates diagnosis in patients with "cryptogenic" chronic hepatitis.     

Hepatitis C virus seroconversion rate in established blood donors

The results of hepatitis C virus (HCV) antibody test of 237, 813 blood donations collected from 143, 815 donors by the West Midlands Blood Transfusion Centre in 1993 were analyzed retrospectively in order to determine the seroconversion rate among established previously anti-HCV negative donors. Three hundred sixteen (0.22%; 1 in 455) donors were positive by the enzyme linked immunosorbent assay (ELISA) screening test and 34 (0.024%; 1 in 4, 230) donors were positive by ELISA and the Recombinant Immuno Blot Assay (RIBA). Three donors previously negative for HCV antibody reacted positively by both tests. The annual seroconversion rate was calculated as one in 35, 937 donors. This figure argues against limitation of HCV antibody screening to new blood donors. A further 45 donors negative on previous screening reacted positively by ELISA and were indeterminate by RIBA. Unexpectedly, lapsed blood donors first tested for HCV antibody in 1993 had high positive reaction rates by ELSA and RIBA, which was significantly (P < 0.001) higher than those of new donors. RIBA-positive reaction rate among ELISA-positive donors was significantly higher amongst males than females (P < 0.0011. © 1995 Wiley-Liss, Inc.     

Evaluation of the new ARCHITECT anti-HCV screening test under routine laboratory conditions

BACKGROUND: An improved test version of the Abbott ARCHITECT anti-hepatitis C virus (HCV) test became available at the end of 2005. STUDY DESIGN: We compared the new test version with the Ortho Vitros anti-HCV test by evaluating 2034 serum samples in parallel on both systems under routine laboratory conditions. Discordant samples were tested in the Inno-LIA HCV Score assay as well as in the RIBA HCV 3.0. RESULTS: Of the 2034 samples 140 (6.9%) yielded positive and 1856 (91.2%) negative results in both assays. We observed discordant results in 38 samples (1.9%). All discrepant samples showed a low S/CO ratio of 1.0-6.9 (mean 2.8) in the Ortho assay and of 1.3-3.0 (mean 1.96) in the ARCHITECT assay. As expected, most of them could not be confirmed by immunoblot testing. Comparison of the results of the two immunoblots (Inno-LIA and RIBA) revealed a great variability in test results. CONCLUSIONS: This study represents the first comparative evaluation of the modified version of the Abbott ARCHITECT anti-HCV assay in comparison with the Ortho Vitros anti-HCV test. Under routine laboratory testing, we observed good overall concordance between the two assays and no evidence that one assay shows more false-reactive or negative results than the other.     

聚合酶链反应鉴定丙型肝炎病毒母婴传播的状态及其…

采用多种方法,动态检测了１１例丙型肝炎病毒感的孕妇所生的婴儿血抗－ＨＣＶ和ＨＣＶＲＮＡ。发现用合成肽酶联免疫吸附试验检测婴儿抗－ＨＣＶ阳性率显著低于第二低重组抗原ＥＬＩＳＡ;用２ｎｄＥＬＩＳＡ检测,６例婴儿脐血和静脉血抗－ＨＣＶ阳性,５例持续１－５月阴转,１例阳性持续１３个月。     

Evaluation of a total hepatitis C virus (HCV) core antigen assay for the detection of antigenaemia in anti-HCV positive individuals

A new, sensitive enzyme immunoassay has been developed for detecting and quantifying total hepatitis C virus (HCV) core antigen in anti-HCV positive or negative sera ("trak-C", Ortho Clinical Diagnostics, Raritan, NJ). The purpose of this study was to evaluate the performance of trak-C as an additional laboratory diagnostic marker of viraemia. The performance was compared to HCV-RNA detection in the "screening" of sera from a large heterogeneous population of hospitalised patients and outpatients. Six hundred and eighteen anti-HCV negative sera, 405 anti-HCV positive/HCV-RNA negative sera, 604 anti-HCV positive/HCV-RNA positive sera and 67 anti-HCV negative sera containing antigens or antibodies potentially interfering with the performance of the assay were analysed. Supplemental HCV antibody testing was performed using a commercial strip immunoblot assay. HCV-RNA was investigated using a qualitative commercial assay. A quantitative commercial RT-PCR was used for the analysis of selected samples. Sensitivity and specificity values were 94.7 and 100%, respectively. The latter was also confirmed when anti-HCV negative samples containing potentially interfering antigens/antibodies were examined. Sensitivity below 100% was probably due to an antigenaemia below the detection limit of trak-C. Besides, because 65.6% of HCV-RNA positive/trak-C negative samples presented specific antibodies against all four RIBA antigens, the hypothesis was raised that, in some cases, the dissociation step efficiency could be sub-optimal. In conclusion, trak-C seems suitable for identifying HCV infection on large based populations. It is a rapid to perform, reliable and specific assay that can be adapted to any laboratory setting.     

New generation RIBA hepatitis C strip immunoblot assays.

Second generation hepatitis C virus (HCV) Elisas are currently in use in Europe and have been submitted for approval in the United States. These new assays contain additional antigens from the putative nucleocapsid and NS-3 regions of the HCV genome in addition to the c100-3 antigen present in first generation Elisas. A supplementary test, the second generation RIBA (Chiron Co trademark) HCV strip immunoblot assay (2-RIBA HCV SIA) has also been developed. The strip immuno-blot assay uses four recombinant HCV antigens (5-1-1 [NS-4], c100-3 [NS-4], c33c [NS-3], and c22-3 [NS-3 [nucleocapsid]) slot blotted on nitrocellulose. Screening of random volunteer blood donors with the Ortho (Ortho Diagnostic Systems trademark) second generation HCV Elisa (2-Ortho HCV Elisa) indicates that a substantial change in the repeat reactive donor population is observed with the new test. Two notable features of this change are: i) a large number of samples reactive in the 2-RIBA HCV SIA for the second generation antigens, c33c and c22-3, are detected by the 2-Ortho HCV Elisa; ii) the percentage of 2-Ortho HCV Elisa reactive specimens found indeterminate (reactive for only one HCV antigen) by the 2-RIBA HCV SIA is higher than in first generation HCV Elisas (approximately 25 versus 5%). In addition, 2-ortho HCV Elisa repeat reactive, 2-RIBA HCV SIA indeterminate samples are dominated by reactivity to c22-3 instead of c100-3 which is the case for first generation HCV Elisa repeat reactive samples.(ABSTRACT TRUNCATED AT 250 WORDS)     

A cost-effective algorithm for the diagnosis of Hepatitis C virus infection and prediction of HCV viremia in Cameroon

Conventional tests for antibody to Hepatitis C virus (HCV) and HCV RNA require considerable time before results are available, remain very expensive and are not adapted to many sub-Saharan African countries where HCV is endemic. The aim of this study was to evaluate the accuracy of an algorithm consisting of two HCV rapid tests to diagnose and predict HCV viremia in patients in Cameroon. Three hundred and twenty nine plasma samples were screened by two HCV rapid tests (ImmunoComb II HCV, PBS Orgenics and Hexagon HCV, Human). Previous evaluation of these samples for HCV antibodies (anti-HCV) by conventional third generation ELISA, considered as a reference test, indicated that 168 were anti-HCV negative and 161 positive. Among the 161 anti-HCV positive plasma, 114 (71%) were HCV RNA-positive by RT-PCR assay. The ImmunoComb II HCV test provided the more sensitive detection of anti-HCV (sensitivity: 99.4% with a 95% CI = 96-100%). Surprisingly, the second HCV rapid test, Hexagon HCV, showed a high capacity to identify non-viremic subjects amongst anti-HCV positive cases (93.6% [95% CI: 82-99%]). These results suggest an algorithm using ImmunoComb II HCV as a first test to screen anti-HCV positive subjects, and Hexagon HCV as a second test to discriminate between viremic and non-viremic HCV seropositive subjects.     

High proportion of false positive reactions among donors with anti-HCV antibodies in a low prevalence area

Among 39, 656 voluntary blood donors in Okinawa Prefecture, Japan, 115 (0.29%) were repeatedly reactive for antibody to hepatitis C virus (anti-HCV) by second generation (2nd-gen) passive hemagglutination assay (PHA). Positive serum samples were tested for anti-HCV using three different enzyme immunosorbent assays (ELISAs; Abbott 2nd EIA, UBI-HCV-EIA, JCC-2) and for HCV-RNA by the polymerase chain reaction (PCR). The 115 2nd-gen PHA-positive sera were divided into three groups according to the agglutination titers; >2¹⁰ (high titer group), 2⁷?2⁹ (median), 2⁵?2⁶ (low). All but one serum (44/45) in the high PHA titer group reacted in each of the three second screening ELISAs. Furthermore, 43 (97.7%) of the 44 sera contained HCV-RNA by PCR. In the median titer group, 11 of the 13 samples tested were positive by each of the three ELSIAs, and 4 (36.4%) of the 11 showed reaction by PCR. On the other hand, all of the 38 sera tested in the low titer group were negative for HCV-RNA by PCR, and 24 of the 38 were also negative by each of the three ELISAs. Most of the low titer positive reactions in the 2nd-gen agglutination assay seemed to be false positive. In Okinawa Prefecture, the prevalence of anti-HCV among blood donors is much lower than in the rest of Japan (0.29% vs. 1.11%). Moreover, a significant proportion of these sera were low titer by the PHA assay. The difference in the genuine anti-HCV-positive rate, or the prevalence of HCV carriage between Okinawa Prefecture and the rest of Japan may therefore be even greater than is presently assumed. © 1995 Wiley-Liss, Inc.     

Study on reliability of commercially available hepatitis C virus antibody tests.

The serodiagnosis of hepatitis C virus (HCV) infection was analyzed by a recombinant immunoblot assay (RIBA) with recombinant proteins encoded by the viral RNA isolated from our patients in Hamburg, Germany. The HCV RNA was amplified by PCR, and proteins encoded by the viral core and the NS3, NS4, and NS5 regions were expressed subsequently in Escherichia coli. The results obtained with our UKE RIBA were compared with the results of the Abbott HCV second-generation enzyme immunoassay (EIA). Serum samples from 270 patients, which were sent to us on the suspicion of HCV hepatitis and which were negative for hepatitis A virus and hepatitis B virus antibodies, were examined. In 227 cases (84.1%), there were identical positive (204 cases, 75.6%) or negative (23 cases, 8.5%) results in both tests. In 32 cases (11.9%), the reactive Abbott second-generation HCV EIA results could not be confirmed by the UKE RIBA and the HCV PCR. In follow-up studies conducted over 1 year, these results did not change. In three cases (1.1%), the UKE RIBA presented a positive result while the Abbott second-generation HCV EIA was negative. All three cases were positive in the HCV PCR and showed seroconversion in an HCV EIA 4 to 6 weeks later. In addition, 33 patient serum samples were examined by UKE RIBA in parallel with the Ortho RIBA 2.0. In three cases (9.1%), a positive Ortho RIBA 2.0 result could not be confirmed by the UKE RIBA and the HCV PCR. All three patients were free of complaints. The UKE RIBA showed also a smaller number of indeterminate results (3.0%) than the Ortho RIBA 2.0 (24.2%). This comparison study demonstrates that the commercially available HCV antibody tests should be further improved.     

Prevalence of hepatitis C in South Africa: detection of anti-HCV in recent and stored serum

The prevalence of anti-HCV was studied in a cohort of 2,072 South Africans. The results were compared in selected recently collected sera and in stored sera. The serum ALT and anti-HBc were also studied as surrogate markers in this population. The following groups were tested: (a) 498 urban, black blood donors (b) 500 white blood donors (c) 500 Asian blood donors (d) 216 rural hospitalized patients (e) 358 rural mineworkers. Sera found positive by the original ELISA were retested, and reproducibly positive tests in rural black men (group d) were confirmed both by recombinant immunoblot assay and by a second ELISA. An anti-HCV prevalence of 1.2%, 0.8%, and 0.6% in urban blacks, Asians, and whites was found. Antibodies to hepatitis B core antigen were found in 42.9%, 3.4%, and 1.2% of black, Asian, and white donors, respectively; 76% of donors positive for anti-HCV were anti-HBc negative. In rural African men, 17% of stored serum samples and 9.2% of recently collected serum samples were positive for anti-HCV. In this cohort 3.84% were positive by all three assays. These results suggest that the prevalence of anti-HCV in low and high-risk South African urban blood donors is comparable to high and low prevalence areas in Europe, the United States, and Japan, but indicates a relatively high degree of exposure to hepatitis C in rural African men. The reactivity of stored, frozen sera in this population requires further investigation. In South African urban blood donors, surrogate marker testing will not expedite HCV screening.     

Detection of hepatitis C viraemia in Caucasian patients with hepatocellular carcinoma.

Potential risk factors for the development of hepatocellular carcinoma were analysed in 40 Caucasian patients with this malignancy. A higher proportion (14 of 40; 35%) had evidence of hepatitis C virus (HCV) infection than had evidence of either hepatitis B virus (HBV) carriage (17.5%) or alcohol abuse (30%). In all 14 patients whose sera were reactive by HCV ELISA (Ortho second generation test), the presence of antibodies to HCV were confirmed by recombinant immunoblot assay (Ortho RIBA-2). Furthermore, two independent laboratories detected HCV-RNA in 10 of the 14 (71%) anti-HCV positive sera. Two additional sera were shown to contain HCV-RNA when reanalysed by a modified PCR using oligonucleotide primers designed to amplify a shorter fragment of the 5' noncoding region of the genome. Seven of the anti-HCV positive patients also had evidence of prior HBV infection and 2 admitted to alcohol abuse. HCV infection was the only identifiable risk factor in 6 patients. These data confirm the association between HCV infection and hepatocellular carcinoma and suggest that persistent viral replication accompanies tumour development in the majority of patients whose serum contains anti-HCV.     

Confirmation of hepatitis C virus antibody in blood donors

Of 103,203 donations collected in Scotland and Northern Ireland over a 3-month period and screened for HCV antibody by Ortho or Abbott second-generation ELISAs, 340 were found repeatedly reactive. Supplementary testing with RIBA-2 resulted in 77 being classified as positive, 130 as indeterminate, and 133 as negative. PCR analysis of the positives and indeterminates indicated viraemia in 65 (84%) of the positives and 7 (5.5%) of the indeterminates. To determine if PCR analysis could be eliminated or reduced by further serological testing, all RIBA-2 positives and indeterminates were tested by UBI and Wellcozyme ELISAs and Innolia and RIBA-3 immunoblots. All RIBA-2 positives with bands to more than 1 gene product were detected in all 4 systems, but >60% of RIBA-2 indeterminates were negative in those tests that contain either recombinant antigens or synthetic peptides derived independently from those used by Ortho/Abbott tests. A comparison of data from the 79 reactive with the core (c22) region revealed only 16 samples reactive in all 4 systems as well as Ortho and Abbott. These 16 included all 6 of the PCR positives in the 79 c22 indeterminate samples. ELISAs and immunoblots using independently derived antigens can offer a useful method of screening out nonspecific reactions in Ortho or Abbott ELISAs, hence reducing the need for PCR testing. Some caution is required as all such tests do not contain identical mixes of antigenic material.     

Diagnosis of hepatitis C virus infection using two second-generation enzyme immunoassays with a recombinant immunoblot assay for confirmation

A total of 1,016 serum samples from patients with either non-A, non-B hepatitis or risk factors for hepatitis C virus (HCV) infection were examined in two second-generation enzyme immunoassays (EIAs), the UBI HCV EIA (Organon Teknika, The Netherlands) and the Wellcozyme anti-HCV (Murex Diagnostics, UK), for detection of antibodies to HCV. An immunoblot assay that uses four recombinant antigens, the 4-RIBA (Chiron, USA), was used as a confirmatory assay. Of the 1,016 samples, 195 (19.2 %) were reactive in both EIAs, while ten yielded discrepant results. One hundred eighty of the 195 (92 %) positive reactions were confirmed in the 4-RIBA; 13 sera yielded an indeterminate result and two were negative. None of the sera with discrepant results reacted positively in the confirmatory test, while two sera showed an indeterminate pattern. In contrast to the screening of antibodies to HCV among blood donors, confirmatory testing of antibodies to HCV with the 4-RIBA seems to have limited added value in the diagnostic examination of clinical samples from patients with suspected HCV infection.