Determination of the diagnostic parameters of domestic immunoenzyme test systems versus foreign analogues in the detection of serum rubella virus antibodies

Russian enzyme immunoassay (EIA) test systems (EATS) and foreign analogues (DSL and BCM-Diagnostics, USA) were compared in the detection of human serum rubella virus (RV) antibodies. Analysis of RV IgM levels ascertained a greater agreement of quality indices for the EATS "EKOlab-Krasnukha-IgM" than for the system "VectoRubella-IgM". As compared with the USA reference systems, the sensitivity, specificity, and total agreement of the data obtained by the EATS "EKOlab" were 100, 97.5, and 97.7%, respectively; those were 88, 84.4%, and 85.4% for "VectoRubella-IgM". In healthy individuals, strictly seropositive cases of IgM detection, revealed by the EATS "VectoRubella-IgM" and unconfirmed by the results obtained by the EATS "BCM-Diagnostics-IgM" (8%) are most likely to be regarded as false-positive due to the presence of serum rheumatoid factor (RF). The principle of indirect EIA used in the system "VectoRubella-IgM" makes it impossible to rule out the impact of RF on test results. The EATS "EKOlab-Krasnukha-IgM" and the systems made in the USA apply the principle of EIA with IgM involvement that, unlike indirect EIA, minimize to have nonspecific results. All three analyzed Russian EATS "EKOlab-Krasnukha-IgG", "Krasnukha-screening", and "VectoRubella-IgG" in the detection of RV IgG show rather high diagnostic parameters as compared with the systems made in the USA. The important additional advantage of the EATS "EKOlab-Krasnukha-IgG" over other Russian systems is that the kit has reference serum with the known content of RV IgG. This allows one to give results in absolute units and to standardize the calculations of some independent experiments. The performed study suggests that out of the Russian test systems, EATS "EKOlab-Krasnukha-IgM" and "EKOlab-Krasnukha-IgG" should be preferred.