Immune analysis of natural neurotropic autoantibodies in blood serum of patients with COVID-19 associated ischemic stroke

Abstract

The aim of the present study was to perform a comparative quantitative analysis of natural neurotropic autoantibodies (Nabs) in blood serum of patients with COVID-19 associated ischemic strokes (IS) in dynamics of disease. A total of 150 consecutive patients with acute primary IS were included, being divided in two groups: 100 patients with IS on the background of COVID-19 pneumonia (main group No. 1) and 50 patients with IS without COVID-19 symptoms and positive viral test (comparison group No. 2). The stroke severity and consciousness were measured by NIHSS and Glasgow coma scale. In blood serum of patients (n = 110), we have studied the levels of IgG Nabs to NF-200, GFAP, S100β, MBP, receptors to dopamine, serotonin, choline, glutamate, GABA by means of ELISA technique. The blood samples for analyses were taken at the 5th, 14th and 28th days of disease. In group 1 (n = 80), the Nabs levels have been increased as follows: antibodies to NF-200 (132.9±4.1 CU), by 1.09 and 1.8 times; for GFAP (118.9±3.9 CU), by 1.4 and 2 times; S100β antibodies (129.5±10.2 CU), by 1.05 and 1.6 times; MBP antibodies (97.3±4.5 CU) were 1.14 and 1.6 times higher; antibodies to dopamine receptors (77.9±4.4 CU) in 1.2 and 1.6 times; to serotonin receptors (81.96±3.25 CU) in 1.2 and 1.4 times; choline receptor antibodies (61.42±3.6 CU) were increased 1.4- and 1.8-fold; to glutamate (85.28±4.25 CU) by 1.19 and 1.4 times; to GABA (82.4±5.2 CU) the increase was 1.5- and 1.8-fold, respectively, when compared with group 2 and controls. The time-dependent monitoring of Nabs level in patients with COVID-19 associated ischemic stroke showed the highest increase in Nabs to the S-100, NF-200 and MBP proteins at the day +28 following the brain stroke. In patients with COVID-19 associated IS, more enhanced production of serum autoantibodies to neuroproteins and neurotransmitter receptors was detected, which accompanied a worse course of IS and can be considered as a predictor of unfavorable outcome of disease.