COMPARISON OF QUANTITATIVE AND QUALITATIVE CHARACTERISTICS OF THE SYSTEM P- SELECTIN - PLATELETS - VON WILLEBRAND FACTOR - METALLOPROTEASE ADAMTS13 IN PATIENTS WITH SEPSIS, IDIOPATHIC THROMBOCYTOPENIC PURPURA AND HEALTHY INDIVIDUALS

Introduction. The blood coagulation system plays a significant role in the pathogenesis of sepsis. Aim: to evaluate changes in the quantitative and qualitative characteristics of von Willebrand factor (vWF), ADAMTS13 metalloprotease and P-selectin in patients with sepsis, comparing them with those in patients with idiopathic thrombocytopenic purpura and in healthy individuals. Materials and methods. The study included 56 patients who received inpatient treatment due to the development of sepsis of various etiologies, 12 patients with idiopathic thrombocytopenic purpura (ITP) and 50 healthy volunteers. In a venous blood sample, the following studies were performed: vWF antigen (vWF: Ag), GPIb-binding ability of vWF (vWF:GPIb), binding ability of vWF to type I collagen (vWF:CBAI), binding ability of vWF to type III collagen I (vWF:CBAIII), P-selectin, ADAMTS13 antigen (ADAMTS13: Ag), ADAMTS13 activity (ADAMTS13:AC) and antibodies to ADAMTS13 (ADAMTS13:AB). Results. The median values of vWF:Ag, vWF:GPIb, vWF:CBAI, and vWF:CBAIII were significantly higher in patients with sepsis compared to healthy individuals and patients with ITP. The median P-selectin in patients with sepsis with thrombocytopenia 1213 ng/mL [1104-1302] was statistically signifi cantly higher than in healthy individuals 74.5 ng/mL [65.0-84.5] (p = 0.0001), and with patients with ITP 389.0 ng/ml [276.2-589.2] (p = 0.0001). Median ADAMTS13:Ag in patients with sepsis with thrombocytopenia <100x109/l 0.49 U/ml [0.44-0.71] and in patients with ITP 0.67 U/ml [0.62- 0.76] were significantly lower compared with healthy individuals 0.97 U/ml [0.84-1.08] (p = 0.001 and p = 0.034, respectively), but the median ADAMTS13:Ag in patients with sepsis with thrombocytopenia was statistically significantly lower than in patients with ITP (p = 0.038). In 19.6 % of cases in patients with sepsis, the ADAMTS13:AB index was higher than 10.0 U/ml (19.6 U/ml [12.1-26.7]), while the median P-selectin indicator in this group of patients was significantly higher when compared with a group of patients with sepsis with an ADAMTS13:AB score of less than 10.00 U/mL (3.04 [2.11-3.94]): 1342 ng/mL [1271-1374] vs. 1130 ng/mL [1087-1271], p = 0.003, respectively. Conclusion. Activation of endothelial cells may underlie the increase in quantitative and qualitative indicators of vWF. Meanwhile, the effect of the adhesive characteristics of vWF (vWF:GPIb, vWF:CBAI and vWF:CBAIII) on the number of platelets in the blood of patients with sepsis was not revealed. Adhesion of vWF to the endothelium through interaction with P-selectin through the platelet GPIb receptor can promote the transition of vWF into a conformational-active state and lead to a decrease in the concentration of ADAMTS13 in the circulation.

Automated summary

This study evaluated the quantitative and qualitative changes in von Willebrand factor (vWF), ADAMTS13 metalloprotease, and P-selectin in patients with sepsis. The results showed that the levels of vWF, P-selectin, and ADAMTS13 were significantly different between patients with sepsis, healthy individuals, and patients with idiopathic thrombocytopenic purpura (ITP).