Blood rheology factors for thrombus formation in some oncohematological diseases
E. V. Roitman, I. M. Kolesnikova (Moscow, Russia)
Time: 17:15 - 18:15
Objective: High incidence of venous thromboembolic events VTE in cancer patients despite standard antithrombotic prevention suggests the presence of non-hemocoagulation conditions for thrombosis development in cancer patients. The aim was to study the blood rheological features and their role for thrombosis in patients with some oncohematologic diseases.
Methods: Study’s population consisted and 48 children with acute lymphoblastic leukemia (ALL), 26 adults with polycythemia vera (PV), 14 adults with chronic myeloid leukemia (CML), 14 adults with acute myeloid leukemia (AML) and 67 volunteers as the control group. All patients had not any symptomatic organs failures. Hematocrit (Hct), erythrocytes count, leukocyte count and fibrinogen were analyzed. Moreover in all patients we investigated B-type natriuretic peptide concentration (BNP). Whole blood viscosity (WBV) under shear rates range 5-300s-1, plasma viscosity by shear rate 250s-1 were measured with using «cylinder - cylinder» rotational viscometer (AKR-2, Russia). Measurement was performed as decreasing of shear stress (γ̇) (from 300 to 5s-1) followed by an increasing γ̇ (from 5 to 300s-1). No sample extracting from device till the analysis is performed. WBV values were adjusted to Hct=40%.
Results: Elevated BNP had 18-20% of patients assuming subclinical cardiac dysfunction which is an independent VTE risk factor. In all patients WBV differed from normal. The highest WBV was found in patients with PV, the lowest - in patients with AML. The main differences of the blood rheological behavior were due to the ratio of erythrocyte aggregation/disaggregation processes and the difference in the composition and hydrodynamic resistance cell conglomerates at high shear rates. In donors differences of WBV value depending on the direction of measurement (decreasing/increasing γ̇) at the same shear rate were found by low and middle shear rates. In patients WBV differences showed up at all shear rates implying reversible blood structuring process is not full finished.
Conclusion: Thus these patients are with acquired non-hemocoagulation conditions for thrombosis development. We assume that the revealed hemorheological features in combination with the high concentration of BNP could be one trigger to start of VTE despite standard antithrombotic prevention.