Multicenter evaluation of five commercial rubella virus immunoglobulin G kits which report in international units per milliliter

Abstract

In a multicenter study, the consistency of international units expressed by five commercially available rubella virus immunoglobulin G kits was evaluated. The linearity and within-run and between-run precision were determined for each kit. All kits demonstrated good linearity and had within-run and between-run precision coefficients of variation ranging from 5.1 to 21.7% and from 9.5 to 51.0%, respectively. To compare the international units expressed, the results from 40 samples tested in duplicate were compared with the results of a reference enzyme immunoassay calibrated with World Health Organization international standard serum and a hemagglutination inhibition test. The results of the kits were plotted against those of the reference tests, and linear regression analysis was applied. The Pearson correlation coefficient ranged from 0.64 to 0.75 when the commercial kit results were compared with those of the reference enzyme immunoassay, indicating only a moderate degree of correlation. Therefore, the international units expressed by the commercial kits are insufficiently consistent to be of practical use in diagnostic clinical microbiology.

Characterization of rubella-specific humoral immunity following two doses of MMR vaccine using proteome microarray technology

“…[ 7 , 8 , 9 , 10 , 11 , 12 ] Assays such as whole- rubella virus, recombinant protein and synthetic peptide-based enzyme immunoassays (including immunoblot), hemagglutination inhibition assays, and neutralization assays (including a high-throughput immunocolorimetric-based neutralization assay) have been used in large studies for surveillance of rubella vaccine-induced immunity. [ 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 ] Recent papers and expert reviews from the literature point to the lack of standardization of the international rubella antibody standard and the currently used commercial anti-rubella IgG antibody (Ab) assays (leading to misinterpretation of results), and recommend improved and/or alternative approaches in rubella serology testing (including qualitative testing and/or testing without the use of the existing RUBI-1-94 international rubella Ab standard for calibration of assays). [ 1 , 6 , 21 , 22 , 23 ] Antigen profiling based on a high-throughput microarray technology offers an exciting new opportunity to interrogate the entire viral proteome and assess effective humoral immune responses to vaccination and/or infection.…”