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A promising trend in the diagnosis of systemic autoimmune diseases is the multiplex immune assay (MIA) of autoantibodies and other laboratory biomarkers using microchips. The aim of the work was to study the diagnostic and prognostic significance of MIA antinuclear antibody (ANA) profiles in systemic lupus erythematosus (SLE). 94 patients with SLE, 70 patients with other rheumatic diseases and 30 healthy donors were examined. ANA (antibodies to doublestranded - dsDNA, Sm, SS-A/Ro, SS-B/La antigens, nucleosomes, ribosomal protein P-RibP and ribonucleoprotein - RNP-70) were determined in the serum by MIA using the xMAP technology. In MIA, antibodies to dsDNA, Sm and RibP have a high diagnostic specificity (Sp) (95.0-99.0%) and a likelihood ratio of positive results (LR+) (9.67-15.0), i.e. are the most "useful" diagnostic tests, and antibodies to RNP-70, SS-A/Ro and nucleosomes are classified as "useful" tests for the diagnosis of SLE (Sp: 84.0-95.0%, LR+2.0). Determination of profiles from 3 or more antigen-specific ANA by MIA increases the Sp method to 98.0-100%, and the LR+ - to the maximum values. Profiles from 7 subpopulations of ANA (antibodies to dsDNA, Sm, RibP, SS-A/Ro,SS-B/La, nucleosomes and RNP-70, 57.9%, 71.9%, 82.5%, 61.4 %, 84.2%, 50.9%, 84.2%) were found in the chronic variant of SLE. In the acute course of the disease, 4 subpopulations of ANA are simultaneously detected (antibodies to dsDNA, Sm, SS-A/Ro and nucleosomes, 77.3%, 45.5%, 40.9% and 72.7%); in subacute course there are 2 subpopulations of ANA (antibodies to dsDNA and nucleosomes, 53.3% and 46.7%). The activity index of SLEDAI-2K positively correlates with the concentration of antibodies to dsDNA (r = 0.55, p0.05), nucleosomes (r = 0.65, p0.05), RibP (r = 0.32; p0.05) and Sm (r = 0.36, p0.05) in the blood. There was no reliable relationship between the production of varieties of ANA and the index of organ damage. Mucocutaneous disorders, lupus-nephritis and neurolupus were most often associated with the detection of antibodies to dsDNA (53.2-64.0%), nucleosomes (55.3-66.0%), SS-A/Ro (38.0-40.4%) and Sm (27.8-36.2%). MIA of ANA profiles is an important tool for implementing a personalized approach to diagnosis, evaluation of activity, course and clinical and immunologic subtypes of SLE.

In the review, topical aspects of the study of antinuclear antibodies (ANA) in systemic lupus erythematosus (SLE) are considered. ANA is the main serological marker of SLE. In the sera of patients with SLE, antibodies to DNA, histones, nucleosomes, extractable nuclear antigens (Sm, U1 ribonucleoprotein, Ro / SSA, La / SSB, ribosomal protein P), nucleolar antigens and other cellular structures are detected. The ANA study using indirect immunofluorescence on HEp-2 cells (IIF-HEp-2) is recommended as a standard screening test for the diagnosis of SLE. The use of automated systems for the interpretation of cellular fluorescent tests contributes to the standardization and improvement of the reproducibility of the IIF. A new international nomenclature of types of nuclear, nucleolar (nucleolar), cytoplasmic and mitotic luminescence of ANA in IIF-HEp-2, including 28 variants of anticell ("Anti-cell" - AC) patterns was developed. In the practice of clinical diagnostic laboratories, high-performance automated methods for the determination of ANA based on ELISA, immunoblot, fluorescent, chemiluminescent and multiplex immunoassay are widely used. New mono- and multiplex methods of solid-phase analysis are expediently used as confirmatory reflex tests for the detection of varieties of antigen-specific ANA in patients with SLE with positive results of IIF-HEp-2. Identification of ANA profiles using multiplex technologies is a useful tool for implementing a personalized approach to diagnosis, evaluation of activity, prognosis, clinical and immunological subtypes, and the effectiveness of SLE therapy. The need for an ANA study not only to confirm the diagnosis of SLE, but also to identify the disease in the early and preclinical stages with the intention to prevent the development of the pathological process is discussed. Detection of monospecific anti-DFS70 antibodies allows to exclude the diagnosis of SLE inANA IIF-HEp-2 positive subjects. Presented is a modern algorithm for testing ANA with SLE.