ИСТИНА

During the last few years, we have been developing new approaches for quantitative assessment of the of microrheologic properties of blood in pathology, in particular, of the ability of red blood cells (RBC) to reversibly aggregate and their alterations in pathology. These methods include diffuse light scattering implemented in RheoScan device (Korea), cell manipulation and interaction forces measurement implemented in home-made laser tweezers, and digital capillaroscopy implemented in the Kapilyaroscan-1 device (Russia) using machine learning for digital image processing. We characterize the intrinsic properties of RBC to reversibly aggregate by measuring the aggregation index, aggregation rate, hydrodynamic strength of aggregates, paired aggregation and disaggregation forces. These measurements are performed in vitro in the samples of blood freshly drawn from healthy donors or patients suffering from socially important diseases. The measurements of the capillary blood velocity (CBV) and the number and size of RBC aggregates in the nail bed capillaries with digital capillaroscopy are performed in vivo. Three groups of patients were formed for the study with the main diagnoses of atrial fibrillation, coronary heart disease, and chronic heart failure. Statistical differences in parameters for different groups of patients were analyzed using the nonparametric statistical Mann-Whitney test (p<0.05). The correlation between all measured characteristics of RBC aggregation was calculated according to the Pearson coefficient of linear correlation. The results of the study showed a significant correlation between the measured parameters for all groups of patients. In particular, there is a significant correlation between the presence of aggregates in the capillaries and a decrease in CBV in the examined patients. The study was financially supported by the Russian Science Foundation grant № 22-15-00120.