Comparison of RFFIT Tests with Different Standard Sera and Testing Procedures / 中国病毒学·英文版

The World Health Organization (WHO) standard assay for determining antibody level is the rapid fluorescent focus inhibition test (RFFIT) and is used to determine the degree of immunity after vaccination against rabies.To compare the difference in RFFIT results between the laboratories of The National Institute of Infectious Disease in Japan (NIID) and the Chinese Centre for Disease Control (CCDC) as well the influence of the choice of standard serum (STD) for the detection,the two laboratories detection methods were simultaneously manipulated by RFFIT.The reference serums used in NIID and the WHO standard serum used in CCDC were compared in the same RFFIT detection to determine the titer of four sera samples C1,S1,S2 and S4 in parallel,and the titers of the detected sera samples were calculated using the standard formula for neutralizing antibody titer.No significant difference was found in RFFIT methods from the two laboratories and the RFFIT testing procedures of the two laboratories have good consistency.However,different titers were obtained with the tentative internal standard serum (TI-STD) produced by adjusting to 2.0 IU of WHO standard serum in NIID and the WHO STD.The titer determined with the TI-STD was higher than that determined with WHO STD,This difference appears to be significant and requires further investigation.

The Results of External Proficiency Tests to Prevent Transfusion-transmitted Virus Infection: There Is a Need for a Quality Assurance Program for Donor Screening Tests to Prevent Blood-borne Virus Infections / 대한수혈학회지

BACKGROUND: We analyzed the results of external proficiency tests for HBsAg, anti-HCV and anti-HIV, and these tests are currently used for blood donor screening in Korea. METHODS: The external proficiency testing (EPT) data was retrospectively collected from 2001 to 2009 from the Korean Association of Quality Assurance for Clinical Laboratories, and this association includes those institutes that have blood centers. The pooled patient sera or converted sera from the plasma were used for EPT. The year 2004 data includes the Recombinant HBsAg variant (Gly/Arg 145). RESULTS: A total 806 institutes participated in this evaluation. The average discordant rate for HBsAg, anti-HCV and anti-HIV in the blood centers was 0.2%, 0.6% and 1.0%, respectively for the years 2001~2009. For the HBsAg test, the discordant rate was less than 0.5% in 2009, yet there was a much higher rate (1.6~22.2%) in 2004 when using the recombinant HBsAg variant. CONCLUSION: HBV variants or low positive antigen or antibody titers were problematic in the current clinical laboratory, and so a systematic quality assurance program should be conducted with using control materials.

External Quality Assurance Survey for the Blood Donor Screening Tests Performed in 2010 / 대한수혈학회지

BACKGROUND: To prevent blood-borne infections and guarantee safe transfusion, we proposed a quality assurance program for donor screening tests, such as hepatitis B surface antigen (HBsAg) and anti-hepatitis C virus antibody (anti-HCV), by introducing external proficiency testing for the laboratories that perform donor screening tests. METHODS: The materials for external proficiency testing (PT) were prepared from the HBsAg Standard Panels and anti-HCV Reference Panels provided by the Korea Food and Drug Administration (KFDA), and the normal Human Serum was provided by the Serum Bank of the Korea National Research Resource Center. The external PT materials were sent to 83 laboratories that performed donor screening tests after evaluating their quality. RESULTS: The results of evaluating the quality of the PT materials were acceptable. All the laboratories receiving the materials answered with a 100% response rate. All the laboratories answered that they obtained positive results for the HBsAg Standard Panel E, H, I and J; however, one laboratory answered in the gray-zone and that lab had negative results for HBsAg Standard Panel C and G. Seventy laboratories (84%) and 42 laboratories (51%) among the total 83 laboratories answered they had positive results for HBsAg Standard Panel B and D, suggesting that many laboratories could not detect a low level of HBsAg. All 83 laboratories answered that they had concordant results for the external PT for anti-HCV. CONCLUSION: Donor screening laboratories can detect low levels of HBsAg and anti-HCV without any errors and the performance of the laboratories that could not detect low levels of HBsAg remains to be improved. Quality assurance program using external PT with materials that contain various genotypes and mutants should be conducted to maintain the quality of donor screening tests.