In addition, the underestimation of HCV Ag values based on the correlation with HCV RNA has also been reported in some specimens

In addition, the underestimation of HCV Ag values based on the correlation with HCV RNA has also been reported in some specimens. kits. Results All specimens in the regional reference panel were diagnosed correctly by Mouse monoclonal to GFP all anti-HCV kits, although the distributions of the quantified values varied, and the ratios of titer classification were not identical across kits. All HCV RNA kits quantified the International Standard with minimum deviation and diagnosed the specimens of the reference panel correctly. The quantified values of the International Standard by two HCV Ag kits were inconsistent. HCV Ag titers of some specimens were underestimated owing to the amino acid polymorphisms in comparison with HCV RNA titers. Conclusions The evaluation with International Standards and the regional reference panel was useful for assessing the quality of screening and diagnostic kits for HCV infection, and such quality control is essential for the clinical usage of these kits. screening and diagnostic kits for HCV infection available in Japan and other countries. These kits are inspected by the national regulatory authority in each country to verify their qualities before being released to the market. In Japan, when releasing new kits, the regulatory authority requires the same or better performance than preexisting kits on the market; the regression coefficient (slope of the correlation equation) of quantified values between new and preexisting kits should be between 0.9 and 1.1, and the coefficient AS703026 (Pimasertib) of determination (R2) of these kits should be over 0.9. On the other hand, postmarketing surveillance is also considered AS703026 (Pimasertib) to be important in maintaining the performance of these kits. Several kits are known to be affected by HCV genotypes and polymorphisms of nucleotides or amino acids, and predominant genotypes or strains may have regional specificity and change over time (Saeed et?al., 2009; Murayama et?al., 2012; Momose et?al., 2018). To assess the performance of screening and diagnostic kits for HCV infection, International Standards for these kits and a regional reference panel are suitable. International Standards are approved by the World Health Organization (WHO) as a master calibrator of the international unit (IU), and a regional reference panel is built up by gathering the samples that are endemic in each region. In this study, using International Standards for HCV RNA and HCV Ag, as well as a recently established regional reference panel, we evaluated a number of screening and diagnostic kits, including 13 anti-HCV detection, 5 HCV RNA quantification, and 2 HCV Ag quantification kits. Methods International Standards of HCV RNA and HCV Ag International Standards are approved by the WHO for calibration of IUs. The sixth International Standard for HCV RNA genotype (GT) 1a (IS-RNA; NIBSC code: 18/184) and the first International Standard for HCV core antigen GT-1a (IS-Ag; PEI code: 129096/12) were obtained from the National Institute of Biological Standards and Control (NIBSC, UK) and Paul-Ehrlich-Institut (PEI, Germany), respectively. These International Standards were stored at -80C until use. Establishment of Regional Reference Panel The regional HCV reference panel was established with 70 HCV-negative (CN1CCN70) and 80 HCV-positive (C1CC80) plasma AS703026 (Pimasertib) specimens that were provided by the Japanese Red Cross Blood Centers. These specimens were collected in 2014 and 2015 in Japan and were determined to be ineligible for transfusion. The HCV genomes in samples of the positive reference panel were amplified by nested PCR, and genotypes were determined as reported previously (Furui et?al., 2011). The positive reference panel included HCV strains of GT-1b (28; 35.0%), GT-2a (26; 32.5%), and GT-2b (26; 32.5%), which are in agreement with the predominant genotypes in Japan. These specimens were aliquoted in 1.0-mL volumes into 1.5-mL screw-cap tubes after centrifugation to exclude agglutinates or clots and then stored at??80C until use. Evaluation of HCV.