[THE CLINICAL INFORMATIVENESS OF AUTOMATED METHODS OF SCREENING DETECTION OF ANTI-NUCLEAR ANTIBODIES USING INDIRECT...

Thew antinuclear antibodies (ANA) consist heterogeneous group of auto antibodies reacting with various components of nucleus and cytoplasm. The ANA is a main serological marker of systemic lupus erythematosus (SLE). The implementation in clinical practice of new highly productive techniques of immune analysis using automated systems sets up prerequisites for standardization and amelioration of reproducibility of detection of ANA. The study was carried out to compare diagnostic significance of automated techniques of screening detection of ANA (indirect immunofluorescence test on cells HEp-2 (IIFT-HEp-2)), enzyme-linked immunosorbent assay (ELISA) and multi-complex immune analysis (MIA, using suspension technology xMAP) in serum of patients with SLE. The serums from 94 patients with SLE were analyzed. The comparison group included 70 patients with other rheumatic diseases. The control group consisted of 30 healthy donors. The screening detection of ANA using technique IIFT-HEp-2 was implemented on automated platform AKLIDES, ELISA - on automated analyzer ALEGRIA and MIA on automated analyzer BioPlex 2200. The technique IIFT-HEp-2 demonstrated the most high diagnostic sensitivity as compared with ELISA and MIA- BioPlex 2200 (96.8%; 79.8% and 82.9% correspondingly). The general diagnostic specificity of detection of ANA using technique IIFT-HEp-2 was lower than in case of ELISA and MIO-BioPlex 2200 (40%, 70% and 57% correspondingly). In the group of healthy donors the lowest diagnostic specificity was observed in ANA screening analysis using MIA-BioPlex 2200 (80%) while in case of applying IIFT-HEp-2 and ELISA indices of diagnostic specificity made up 93.3% and 96.7% correspondingly. The ANA analysis of mix of 26 nuclear antigens using ELISA technique was a reliable laboratory test for diagnostic of SLE (likelihood ratio of positive result - 2.66). By the level of likelihood ratio of negative result of the IIFT-HEp-2 technique was more informative test for exclusion of diagnosis of SLE than techniques of ELISA and MIA-BioPlex 2200 (0.08; 0.29 and 0.3 correspondingly). The detection of ANA using technique of is the most preferable primary screening test for diagnostic of SLE. The ELISA of antibodies to mix of nuclear antigens and MIA on the basis of xMAP technology are less preferable screening tests for diagnostic of SLE as compared with IIFT-HEp-2 because of false-negative results in 20% and 17% of cases correspondingly. ELISA and MIA are to applied as confirmatory screening tests permitting to detect antigen-specific ANA in patients with SLE with positive results of IIFT-HEp-2.