Evaluation of ARCHITECT HCV Core Antigen Assay / 대한진단검사의학회지

BACKGROUND: Hepatitis C virus (HCV) core antigen (Ag) levels are known to be well correlating with HCV RNA levels, and may be used as an alternative marker of HCV replication for monitoring the response to HCV treatment. However, the low sensitivity of HCV core Ag assay has been an obstacle for clinical use. In this study, recently developed ARCHITECT HCV Ag assay (Abbott Laboratories, USA) was evaluated for analytical performance and clinical usefulness. METHODS: A total of 109 sera from HCV infected patients including various genotypes of HCV (1b, 2, 2a/2c, 2b, and 3a) and 20 sera from healthy donors were used for evaluating the sensitivity, precision, and linearity of the HCV core Ag assay. The cross reactivity with HIV, hepatitis B virus and myeloma proteins (N=5, each) and correlation with HCV RNA PCR assay were also evaluated. RESULTS: The sensitivity of the HCV core Ag assay was 97.2% (106/109) and there were no false positive results and cross reactivity. The within-run, between-run and between-day CVs were 3.0%, 2.5% and 3.0%, respectively. The levels of HCV core antigen showed a good correlation with those of HCV RNA quantification (r=0.940). The HCV Ag assay showed an excellent linearity in the range from 0.63 to 17,114 fmol/L (r=0.999). CONCLUSIONS: The ARCHITECT HCV Ag assay was good in sensitivity, precision, and linearity and its results well correlated with HCV RNA levels. This assay could be used as a good marker of viral replication for monitoring the therapy response in chronically HCV infected patients.

Evaluation of the HCV core antigen assay as a second-line supplemental test for diagnosis of active hepatitis c infection

Hepatitis C virus core [HCV] antigen assays have been produced to exclude infectious donations collected the preseroconversion window phase. For the same purpose, we evaluated the specificity and sensitivity of a novel hepatitis C virus core antigen detection immunoassay and the applications of this assay in clinical diagnosis. Samples were collected from 30 anti-HCV antibody negative healthy subjects [Gi], and 46 anti-HCV antibody positive patients [G2]. All included samples were subjected to HCV core antigen and HCV-RNA PCR. Among the 46 anti-HCV Ab positive samples, HCV core antigen was positive in 38 samples from 40 samples positive for HCV-RNA with sensitivity of 95% [38/40]. All the 30 anti-HCV Ab negative samples [n=30] were negative for both HCV core antigen and HCV-RNA with specificity of 100% .There was no significant variation in the sensitivity of HCV core antigen between genotype 1 [100%] and genotype 4 [94.5%]. Viral load in HCV core antigen positive samples [906653 +/- 133803] was significantly increased than that of HCV core antigen negative samples [16342 +/- 5245] with P value<0.05. HCV core antigen assay is a useful method in screening strategy of HCV infection and provides a reliable means of distinguishing between current and cleared HCV infections that is well correlated with HCV-RNA testing

Prevalence of HCV infection in patients on haemodialysis: survey by antibody and core antigen detection.

PURPOSE: The present study was undertaken to determine the prevalence of HCV infection by antibody testing and HCV core antigen (HCVcAg) determination by ELISA in haemodialysis patients and to evaluate the HCV c Ag assay in the detection of HCV infected patients on haemodialysis. MATERIALS AND METHODS: A total of 151 chronic renal failure patients on haemodialysis from May 2003 to October 2004 were studied. One hundred patients out of 151 were followed for 2-5 months. All the patients were tested for anti HCV and HCV core antigen once a month. Anti HCV ELISA positive specimens were confirmed by RIBA. RESULTS: The overall prevalence of HCV infection was 13.23%. Antibody positivity was observed in 9.93% and HCVcAg alone was detected in 2.64%. One patient (0.66%) was initially positive for core antigen and later seroconverted. CONCLUSIONS: Screening for HCV antibodies alone does not exclude infection with HCV in patients on haemodialysis and HCVcAg may be a useful test for identifying HCV infected patients on haemodialysis in the early phase of infection before seroconversion.