A collaborative study to establish the 1st national standard of prekallikrein activator in Korea

A collaborative study to establish the second national standard for hepatitis B immunoglobulin in Korea

This study aimed to establish a second national standard for hepatitis B immunoglobulin (HBIG) that can be used for potency assays of hepatitis B and normal immunoglobulin. The candidate material was manufactured using a process approved as Good Manufacturing Practice. The freeze-dried candidate preparation was tested for physicochemical and biological properties, including pH, residual moisture, molecular size distribution, and potency. A collaborative study was performed involving four laboratories, including the National Institute of Food and Drug Safety Evaluation, as an official national control laboratory in Korea and manufacturers. The potency was calibrated against the second international standard for HBIG using two enzyme immunoassays: enzyme-linked immunosorbent assay and electrochemiluminescence immunoassay. Results from 240 assays were obtained from four laboratories, and combined potency estimates were obtained by calculating the geometric means. Intra- and inter-laboratory variability showed acceptable geometric coefficients of variation of 1.3-6.0 and 3.2-3.6%, respectively. The candidate preparation showed satisfactory stability in accelerated thermal degradation and real-time stability tests. Based on these results, the potency value of 105 IU/vial was assigned (95% confidence intervals: 100.0-109.2 IU/vial), and it was deemed suitable to serve as the Korean national standard for HBIG.

Collaborative study to establish a proficiency panel of hepatitis B surface antigens for evaluating in vitro diagnostics

Hepatitis B virus (HBV) infection is a critical health issue. In hospitals, in vitro diagnostic devices (IVDs) are used to detect HBV infections. The Taiwan Food and Drug Administration has prepared a candidate hepatitis B surface antigen (HBsAg) proficiency panel as an analytical standard to evaluate the sensitivity of the postmarketing surveillance of HBV IVDs. The sensitivity and stability of the proficiency panel, which comprises 5 HBsAg positive sera (SN-A to E) and 1 negative serum, was determined by a collaborative study involving 8 collaboratories. The potency of the candidate proficiency panel was consistent among all collaboratories. The potencies of sera SN-A to E in semiquantitative and quantitative analyses were 2.823-0.011 and 2.229-0.009 IU/mL, respectively. The mean coefficients of variation (CV) of intra and interday precision among the collaboratories were <7%. Accelerated degradation and long-term storage tests were used as stability assays. The candidate HBsAg proficiency panel exhibited good stability under different storage conditions, while all CVs were <6%. In conclusion, this candidate HBsAg proficiency panel is credible and reliable. Therefore, it can be used for postmarketing surveillance of HBV IVDs and quality assessment by clinical researchers and IVD manufacturers.