Specific antinuclear antibodies in different fluorescence patterns of antinuclear factor on the HEp-2 cell line in children with autoimmune diseases

Antinuclear antibodies (ANA) are a family of autoaggressive antibodies directed against different components of the nucleus and cytoplasm of cells. The detection of ANA is of primary importance for the laboratory diagnosis of autoimmune diseases (AID). The aim of our study was to compare the presence of specific antinuclear antibodies with different types of antinuclear factor luminescence in children with autoimmune diseases using the HEp-2 test cell line. The study included 40 children (34 girls and 6 boys) with AID who were being treated at the National Medical Research Center for Children’s Health. The age of the patients ranged from 6.28 to 17.99 years. All children were diagnosed with antinuclear factor (ANF) on the HEp-2 cell line (epithelial cells of human laryngeal cancer) by means of indirect immunofluorescence reaction (AESKUSLIDES® ANA-HEp-2, Germany) using a HELIOS® analyzer (AESKU.GROUP, Germany). ANA was determined using a Q-Processor analyzer using Protea ANA Profile 18 panels (ProteomeTech Inc., Korea), which applies the immunoblot analysis method for the qualitative detection of autoantigen-specific IgG antibodies. A positive ANF titer was detected on the HELIOS® analyzer in all children with AIS (100%). Using the Protea ANA Profile 18 panel, specific ANA was identified in 75% of patients (30 children). In our sample of children with AID, homogeneous (AC-1) and nuclear large-granular (AC-5) types of ANF luminescence, as well as their combinations, were most often detected. In the homogeneous type (AC-1) of ANF glow, autoantibodies to dsDNA, Nucleosome and Histone were more often detected. In large-granular nuclear (AC-5) antibodies to RNP 70, RNP A and RNP/Sm were determined, in combination with AC-1 + AC-5 – to SSA 60, SSA 52, Nucleosome and Histone, RNP 70, RNP A. We identified single points in the nucleus (AC-7) in 10% (4 children), this type of ANF glow is characterized by a low positive prognostic value. The study of ANF and specific ANA using the Protea ANA Profile 18 panel revealed a coincidence in 75% of cases, and certain ANA are consistent with the types of ANF luminescence. In pediatric diagnostics, it is advisable to determine a wide range of ANA when detecting antinuclear factor on the Hep-2 cell line.