Clinical Evaluation of a Newly Developed Chemiluminescent Enzyme Immunoassay for Hepatitis C Virus Core Antigen in Japan.

An advanced and fully automated chemiluminescent enzyme immunoassay for the hepatitis C virus core antigen (HCVcAg) was recently developed in Japan. We aimed to evaluate its clinical utility. The new Fujirebio assay (Lumipulse Presto HCVcAg [LP-Presto]) was compared with 2 conventional assays (Lumipulse Ortho HCVcAg [LP-Ortho] and Abbott's Architect HCVcAg). Basic assessments of LP-Presto (reproducibility, stability, range of quantitation, and specificity) were performed on 220 frozen sera (83 positive and 137 negative by LP-Ortho) and 206 fresh sera (all negative by LP-Ortho). Correlation analysis was performed and the rates of concordance for each assay were determined. Additionally, the frozen sera of 42 hyperimmunoglobulinemia patients, including 3 unmeasurable by LP-Ortho, were tested by LP-Presto. All the basic assessments of LP-Presto were consistent with the results of LP-Ortho and Architect. The concordance rate between LP-Presto and LP-Ortho for the 220 frozen sera was 99.5% (219/220), and that between LP-Presto and Architect was 99.1% (218/220). LP-Presto (HCVcAg cut-off value; 20 fmol/L) was fully consistent with LP-Ortho (100%), which found 343 sera negative for HCVcAg. All 42 hyperimmunoglobulinemic sera were measurable using LP-Presto. In conclusion, the performance of LP-Presto was rapid and reliable, and nonspecific test results due to hyperimmunoglobulinemia were reduced when LP-Presto was used. Therefore, LP-Presto is a high-quality HCVcAg assay that shows promising applications.

[Efficacy of Human Immunodeficiency Virus (HIV) Antigen-Antibody Combination Assay as a Screening Test and Factors Causing False-Positivity].

Purpose: We aimed to evaluate the performance of an HIV antigen-antibody combination assay (fourth-generation) by comparing it with second generation assays that detect anti-HIV. Methods: A total of 105,439 HIV screening tests were performed from January 2004 to March 2015; the second - and fourth generation assays were used for 75,302 and 30,137 samples, respectively. Samples positive on a screening test were confirmed by anti-HIV-1 western blotting (WB) and nucleic acid amplification. By the results of confirmation tests, the efficacies of the second and fourth generation assays were estimated. The clinical backgrounds with false-positive samples were examined. Results: Of 75,302 samples, 136(0.18%) were positive by the second-generation assay; 14 were confirmed positives, and 122 were false positives. Of 30,137 samples, 18(0.06%) were positive by the fourth-generation assay; 6 were confirmed positives, and 12 were false positives. The reliability of the positives by fourth-generation assay was significantly improved (p=0.006) Samples form individuals with malignant neoplasms were frequently false positive by both the second and fourth-generation assays. Of 67 samples performed by WB, 10 samples, including 6 from patients with a malignancy, showed indeterminate results. All indeterminate samples were found to have antibodies responding to HIV core protein. Conclusion: The fourth-generation assay had satisfactory reliability of the positives for HIV screening. Antibodies responding to HIV core protein may result in false positive HIV screening tests. [Original]

Development of DNA-intercalator-polyamine multi-conjugate bearing the ability of the sequence-specific RNA hydrolysis.

A Novel anthraquinone-trisamine modified DNA conjugate was developed. The trisamine-bearing 2,7-disubstituted anthraquinone derivative was introduced into the central position of the DNA oligomer. The ability of the sequence-specific RNA cleavage of this novel modified DNA was investigated.