Neutrophil extracellular traps in patients with ulcerative colitis

Introduction. The pathogenesis of ulcerative colitis (UC) is based on damage to the intestinal mucosa, increased expression of proinflammatory cytokines, and activation of inflammatory cells, including neutrophils. The degree of neutrophil infiltration of the intestinal mucosa determines the severity of clinical manifestations, endoscopic findings, and systemic manifestations of inflammation. Aim. The study was to compare the parameters of the systemic inflammatory response with changes in the ability of neutrophils to form extracellular traps in patients with ulcerative colitis (UC). Materials and methods. The study included 33 patients with UC (group UC), the control group consisted of 20 healthy volunteers (group Control). The ability of neutrophils to form extracellular neutrophil traps (NETs) ex vivo in both groups was determined. The result of stimulation was evaluated by luminescent microscopy, determining the percentage of intact neutrophils, neutrophils of varying degrees of activation, early netosis cells, extracellular traps in the form of a cloud surrounding neutrophil – cloud-shaped NETs, extracellular traps in the form of filaments – filamentous NETs. The capture coefficient of extracellular traps was calculated. Results. After stimulation, significantly large proportions of early netosis cells (p = 0.0003), cloud-shaped NETs (p < 0.0001), filamentous NETs (p = 0.0048) and hyperactivated neutrophils were visualized in the neutrophil preparation of patients with UC in comparison with similar indicators determined in the comparison group. In UC patients, the percentage of intact and hypoactivated neutrophils was significantly lower (p < 0.0001; p = 0.0012, respectively), and the extracellular traps capture coefficient in the UC group was significantly lower (p = 0.0078). Conclusions. The study confirms that the analysis of the ability of neutrophils to form extracellular traps in patients with UC has diagnostic and prognostic value. It allows us to assess not only the severity of inflammation, but also to identify the mechanisms of abnormal immunity in autoimmune pathologies, including UC. Monitoring of netosis helps to determine the depth of remission, which is important for the prevention of complications of the disease. Integrating this approach into diagnostic algorithms can optimize patient monitoring and improve treatment outcomes.