PHENOTYPIC FEATURES OF T REGULATORY CELLS IN EARLY RHEUMATOID ARTHRITIS

<p><strong>Objective:</strong> to investigate the count and characteristics of the phenotype of T regulatory cells (Treg) in the peripheral blood of healthy donors and patients with early rheumatoid arthritis (RA), by using multicolor flow cytometry.<br /><strong></strong></p><p><strong>Subjects and methods</strong>. The investigation enrolled 39 patients with early RA. The percentage and absolute count of Treg (FoxP3+CD25+, surface CD152+, intracellular CD152+, FoxP3+CD127, CD25+CD127, FoxP3+ICOS+, FoxP3+CD154+; and FoxP3+CD274+) was determined by multicolor flow-cytometry. A control group consisted of 20 healthy donors matched for sex and age with the examined patients.<br /><strong></strong></p><p><strong>Results and discussion.</strong> In the patients included in the study, the median [25th; 75th percentiles] DAS28 was 5.01 [4.2; 5.8]; high, moderate, and low activity showed 22 (48.9%), 20 (44.4%), and 3 (6.7%) patients, respectively. The patients with early RA had a lower percentage of FoxP3+CD25+ cells and a lower percentage and absolute count of FoxP3+ICOS+, FoxP3+CD154+, and FoxP3+CD274+ T cells than the healthy donors (p&lt;0.05 in all cases). There was a negative correlation of the percentage of FoxP3+CD25+ cells with C-reactive protein (CRP) (r = -0.4), that of intracellular CD152+ with DAS28 (r = -0.35), erythrocyte sedimentation rate (ESR) (r = -0.46), and CRP (r=-0.54); that of FoxP3+CD127 with CRP (r = -0.42); that of CD25+CD127 with DAS28 (r = -0.38), Simplified Disease Activity Index (r = -0.41), Clinical Disease Activity Index (r = -0.36), ESR (r = -0.39), and CRP (r = -0.47) (p &lt; 0.05 in all cases).<br /><strong></strong></p><p><strong>Conclusion.</strong> The findings suggest that the functional activity of Treg is impaired in early RA, which has an impact on the activity of the inflammatory process.