Usefulness of Anti-HCV ELISA Test and HCV Reverse Transcriptase-PCR for the Diagnosis of Hepatits C Viral Infection / 대한진단검사의학회지

BACKGROUND: The diagnosis of hepatitis C virus (HCV) infection is screened by anti-HCV enzymelinked immunosorbant assay (ELISA) and confirmed by recombinant immunoblotting assay (RIBA) or HCV RT-PCR. We attempted to evaluate the results between anti-HCV ELISA and a qualitative HCV RT-PCR. METHODS: Four hundred and twenty patients who were tested with anti-HCV ELISA and HCV RTPCR, simultaneously, from January 2002 to June 2005 were enrolled in this study. Anti-HCV ELISA was performed by AxSYM HCV version 3.0 (Abbott Laboratories, USA). HCV RT-PCR was performed using in-house RT-nested PCR methods from January 2002 to October 2004 and HCV Genotype Amplification Kit (LiPA) (Bayer Healthcare, USA) from November 2004 to June 2005. RESULTS: Of the 420 patients tested, 321 were positive for anti-HCV ELISA, and 204 were positive for RT-PCR. The positive predictability of anti-HCV ELISA was 63.6%. Among anti-HCV positive patients, RT-PCR was positive in 7.3% of the patients with sample/cut-off (S/CO) or =6. Among the 117 patients with positive anti-HCV, but with negative HCV RT-PCR, 64 had liver diseases such as chronic hepatitis C, chronic hepatitis B, or hepatocellular carcinoma. Twelve patients showed positive HCV RT-PCR, but negative anti-HCV results; of these 9 had hepatic dysfunction. CONCLUSIONS: In the patients who were positive for anti-HCV ELISA with a low S/CO, HCV RT-PCR positivity was shown in a low proportion. Therefore, in such cases, the results should be confirmed by RIBA or HCV RT-PCR. The liver function test showed increased levels of hepatic enzymes in patients with positive HCV RT-PCR, but negative anti-HCV. Such findings correlate to an early phase of chronic hepatitis C, suggesting the necessity of continuous follow up.

Genotypes of Hepatitis C Virus Amplified from Sera Non-Reactive to Anti-HCV Enzyme Immunoassay / 대한임상병리학회지

BACKGROUND: Despite sensitive antibody-based blood-donor screening, a residual risk of transfusion-transmitted viral infections exists. For hepatitis C virus (HCV), window-period donations account for the major risk. In the previous studies, however, estimates of the risk of post-transfusion hepatitis C was much higher than that calculated from the risk of donation in the seroconversion window. Therefore, we reevaluated the rate of HCV RNA positive/ anti-HCV negative samples using the two domestic anti-HCV EIA kits. All the samples showing HCV RNA positive/ anti-HCV negative were genotyped. METHODS: A total of 909 patients' samples showing HCV RNA positivity using the Amplicor HCV TEST (Roche Diagnostic Systems) was retested for antibody presence with the LG HCD 3.0 (LG Chemicals) and DONG-A HCV 3.0 (DONG-A Pharmaceuticals) EIA kit. Samples that were non-reactive to the EIA kits were genotyped by INNO-LiPA HCV kit (INNOGENETICS, Belgium). RESULTS: Among 909 tested samples, 5 samples showed nonreactivity to both anti-HCV EIA kits, while 1 sample was nonreactive only to DONG-A HCV 3.0. When RT-PCR for HCV was performed using stored or follow-up samples, 4 samples showed negative results. Medical records were also reviewed and found to be false positive for HCV RT-PCR in 3 of those 4 patients. In the case of one remaining patient, the follow-up RT-PCR was negative. Finally, 2 samples (0.2%) showed HCV RNA positive/ anti-HCV negative. The 2 samples were genotyped as 1b type. CONCLUSIONS: More than 99.8% of HCV RNA positive samples showed reactivity to anti-HCV EIA kits. There were two samples that were non-reactive to anti-HCV kits and were genotyped as 1b type, which is the most common subtype in Korea. Our study suggests that false negativity of anti-HCV in Korea would very rarely be caused by uncommon HCV genotypes.

Hepatitis C Viral Markers in the Recipients Before and After Kidney Transplantation / 대한임상병리학회지

BACKGROUND: Hepatitis C virus (HCV) has been identified as one of the most frequent causative agent of posttransplant non-A, non-B hepatitis, but the significance of anti-HCV antibodies after transplantation remains controversial. In the present study, we performed anti-HCV and HCV-RNA RT-PCR (HCV PCR) in the kidney recipients to assess the incidence and the outcome of HCV markers after transplantation. MATERIALS AND METHODS: In randomly selected 95 patients' paired sera (before and after transplant samples, respectively), we performed anti-HCV test by Abbott HCV EIA 3.0. We also performed HCV PCR in 80 paired sera of the 95 patients. We evaluated the incidence of anti-HCV and HCV PCR and compared the results in the kidney recipients between anti-HCV test and HCV PCR before and after transplantation. RESULTS: In the recipients' sera before transplantation, 16 (16.8%) among 95 sera were anti-HCV positive and 27 (33.8%) among 80 sera were HCV RNA positive. Among the 80 pretransplant sera performed HCV PCR, 23 (28.8%) discordant results were noted between anti-HCV and HCV PCR, and 17 sera among these were HCV PCR positive and anti-HCV negative. A seroconversion from anti-HCV negative to positive after transplantation was observed in 10 sera, but a conversion from positive to negative was not observed. In case of HCV PCR, a conversion from negative to positive was observed in 21 paired sera, and positive to negative in 13 paired sera. CONCLUSIONS: Our study indicated that disapperance of anti-HCV antibodies after transplantation in kidney recipients was rare. The overall concordance rates between anti-HCV test and HCV PCR in the recipients before and after renal transplantation were lower than other non-transplanted groups reported, and it may be due to the immunosuppressive therapy or the changes in immunoregulatory function of the patients. Further study such as follow-up liver function tests or liver biopsy will be needed for accurate decision about posttransplant HCV status of kidney recipients.