Replacement Study on the Potency Test of Anti- rabies Immunoglobulin in China

Abstract

Objective：To validate the relativity between the rapid fluorescent focus inhibition tests (RFFIT) and mouse neutralization test (MNT), In order to replace potency test of anti-rabies serum/ immunoglobulin. Method: The sample and reference standard were diluted 3-fold serially in 96-well microplate, then mix with a certain amount of challenge virus causing infection of 80%~95% of cells. Incubated at 37 for 1hr for neutralization in vitro, then adding BSR cell to incubate for 24hr and subjected to fluorescence staining. The results were observed by fluorescent microscopy. The 5^th national standard of anti-rabies immunoglobulin was exam with RFFIT and MNT method by the 5^th international standard of anti-rabies immunoglobulin. Validate the repeatability of two methods. Detect the samples of sera, equine rabies immunoglobulin and human rabies immunoglobulin with two methods to validate correlation. Result: the GMT potency of 5^th national standard of anti-rabies immunoglobulin was 23.8IU/ml (RFFIT) and 21.4IU/ml (MNT), and the coefficients of variation were 13.3% and 62.3%. Detect 48 samples with RFFIT and MNT, the results show that the correlation coefficient of the two methods was 0.98, and has a close correlation. Conclusion: RFFIT method can be successfully detected the potency of anti-rabies immunoglobulin, and it can be the alternative method of MNT.