PB1389 - Lymphocyte-platelet adhesion in "FLURONA" (combination of coronavirus infection SARS-COV-2 (COVID-19) and influenza A/H3N2) and SARS-COV-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: We aimed to study the presence of lymphocyte-platelet aggregates in "flurona" (combination of SARS-COV-2 and influenza A/H3N2) and SARS-CoV-2.

Methods: The study enrolled 20 patients with "flurona", 72 patients with SARS-CoV-2 (aged 22 to 70). The control group included 60 healthy people. All examined were representatives of the Caucasoid race in the territory of the Trans-Baikal Region. Lymphocyte-platelet aggregates (LPA) was isolated on a ficoll-urographin gradient (density 1.076). We determined the percentage of LPA using light microscopy (Yu.A. Vitkovsky’s method (1999)). Qualitative variables were described by relative values (%). The results were expressed in average values and the standard deviation (M±SD) was calculated (p < 0.05).

Results: It was found that on the 1st-2d day among patients the number of LPA increased as compared with the control (p < 0.001). The average platelets volume per lymphocyte rasio (LPA-rasio) also increased by 2.9 times (p < 0.05). Among patients with SARS-CoV-2 during 5-6 days there was a notable increase of LPA and LPA-rasio up to 41.3±1.9% and 5.8±0.48 respectively. Patients with "flurona" showed the increase to 21.6± 2.8%, which was 1.5 times higher than in the control (14.1± 1.6%, p< 0.05). On Days 8-9 since the admission in "flurona" and SARS-CoV-2, there were no significant differences in the content of the studied indicators.

Conclusion(s): In the acute period in "flurona" and SARS-CoV2 had an increase in the ability of LPA. The test for measuring LPA indicates the severity level of the disease course, and its implementation in dynamics is used as the parameter for assessing functional activity of immunocompetent cells and stabilizing the pathological process.