Clinical significance of ADAMTS-13/vWF axis in pregnant women at different trimesters of gestation

Introduction. The pandemic of a novel coronavirus infection has demonstrated the importance of assessing the ADAMTS-13/vWF axis in patients with COVID-19, because a decline in this ratio mirrors disease severity. However very few data in the global literature on crosstalk and ADAMTS-13/vWF levels in pregnant women remaining very contradictory are available. Taking into consideration an impact of the ADAMTS-13/vWF axis on prevalence of thrombosis and disorders in the hemostasis system, investigation of this issue is highly demanded.Aim: to assess the functioning of the ADAMTS-13/vWF axis during physiological pregnancy.Materials and Methods. A controlled non-randomized study was conducted: main group included 44 women with physiologically occurring pregnancies at I, II and III trimesters; the control group consisted of 45 healthy non-pregnant women. The plasma level of ADAMTS-13 inhibitor (ADAMTS-13:i), ADAMTS-13 antigen (ADAMTS-13:Ag), vWF antigen (vWF:Ag), and ADAMTS-13 activity (ADAMTS-13:Ac) as well as relevant ratio (ADAMTS-13:Ac/vWF:Ag) were measured.Results. It was shown that in parallel with increasing gestational age, significant changes occurred in the ADAMTS-13:Ac/vWF:Ag ratio. In main group, patients at II trimester were found to have level of ADAMTS-13:Ac/vWF:Ag 0.359 ± 0.121, in III trimester –0.253 ± 0.741, which significantly differed (p < 0.01) compared to control group with non-pregnant women (1,134 ± 0,308).Conclusion. Our study provides new insights into the functioning of the ADAMTS-13:/vWF axis in women with physiologically occurring pregnancy at I, II and III trimesters. Decline in ADAMTS-13:Ac was demonstrated along with increasing vWF:Ag level observed in parallel with increasing gestational age. Apparently, the progressive decrease of ADAMTS-13 concentration during pregnancy is associated with its increased consumption due to high vWF level. However, due to the small single-center patient cohort, further studies with larger-scale studies are needed.