Lymphocyte-platelet adhesion and lymphocyteplatelet clusters in patients with coronavirus infection SARSCOV-2 (COVID-19)

Background : Lymphocyte-platelet adhesion (LPA) is the ability of lymphocytes with CD3 + , CD4 + , CD16 + cell surface markers to form coaggregates with platelets using adhesion molecules, that allows lymphocytes to adhere to the damaged endothelium and migrate into the damaged surface of the vascular wall. Aims : Investigation of the amount of lymphocyte-platelet aggregates and lymphocyte-platelet clusters in patients with COVID-19. Methods : The research involved 168 patients with SARS-CoV-2 (COVID-19) and 100 healthy people of the same age and gender. Patient ' s blood samples were taken on the 1st-2d, 10th-12th, 21st-24th days. The participants of the study were Caucasian race and lived in the Trans-Baikal Territory. The examine of LPA was carried out by the method of Yuri Vitkovsky et al. (1999). The number of lymphocyte-platelet clusters (LPC) was estimated and expressed in rel. units per 100 free-standing cells. The results were expressed in averages and the standard deviation (M ± SD) was calculated. Significant differences were considered for P < 0.05. Results : The authors revealed that on the 1st-2d day of disease among patients the number of LPA increased to 28.9 ± 3.2%, LPC -to 5.0 ± 2.3% as compared with the control group ( P < 0.001). The average platelets volume LPA-rasio also increased by 2.9 times ( P < 0.05). Among patients during 10-12 days of the disease there was a notable increase of LPA and LPA-rasio up to 41.3 ± 1.9% and 5.8 ± 0.48 respectively (higher by 3 times as compared to the control group). On the 21-24th days of the disease with patients being in the hospital, there were no significant differences in the studied parameters among the patients and the control group. Conclusions : There is an increase in the ability of lymphocytes to adhere platelets to their surface and contact with other lymphocytes while forming clusters in the acute phase of COVID-19. Probably the process of clustering is mediated by platelet and leukocyte adhesive molecules.