Coronavirus disease (COVID-19) has become a global pandemic. COVID-19 patients need immediate diagnosis and rehabilitation, which makes it urgent to identify new protein markers for a prognosis of the severity and outcome of the disease. The aim of this study was to analyze the levels of interleukin-6 (IL-6) and secretory phospholipase (sPLA2) in the blood of patients regarding the severity and outcome of COVID-19 infection. The study included clinical and biochemical data obtained from 158 patients with COVID-19 treated at St. Petersburg City Hospital No. 40. A detailed clinical blood test was performed on all patients, as well as an assessment of IL-6, sPLA2, aspartate aminotransferase (AST), total protein, albumin, lactate dehydrogenase (LDH), APTT, fibrinogen, procalcitonin, D-dimer, C-reactive protein (CRB), ferritin, and glomerular filtration rate (GFR) levels. It was found that the levels of PLA2, IL-6, APTV, AST, CRP, LDH, IL-6, D-dimer, and ferritin, as well as the number of neutrophils, significantly increased in patients with mild to severe COVID-19 infections. The levels of IL-6 were positively correlated with APTT; the levels of AST, LDH, CRP, D-dimer, and ferritin; and the number of neutrophils. The increase in the level of sPLA2 was positively correlated with the levels of CRP, LDH, D-dimer, and ferritin, the number of neutrophils, and APTT, and negatively correlated with the levels of GFR and lymphocytes. High levels of IL-6 and PLA2 significantly increase the risk of a severe course by 13.7 and 2.24 times, and increase the risk of death from COVID-19 infection by 14.82 and 5.32 times, respectively. We have shown that the blood levels of sPLA2 and IL-6 increase in cases which eventually result in death and when patients are transferred to the ICU (as the severity of COVID-19 infection increases), showing that IL-6 and sPLA2 can be considered as early predictors of aggravation of COVID-19 infections.

Aim. Using a collection of samples from the biobank ofCityHospital № 40 ofSt. Petersburg, to study the cytokine profile in patients with coronavirus disease 2019 (COVID-19) and sepsis, in comparison with patients with abdominal inflammation and septicemia.Material and methods. The study included serum samples from 181 patients with sepsis and COVID-19 (127 patients with a diagnosis confirmed by polymerase chain reaction (PCR); 54 patients with a negative PCR test, but with a characteristic computed tomographic lung performance) and 47 patients with abdominal sepsis. The content of cytokines was determined using a multiplex immunofluorescence analysis based on the Luminex xMAP technology using the HCYTOMAG60K panel — a soluble CD40 ligand (sCD40L), interleukin-1α (IL-1α), interleukin-1β (IL-1β), interleukin 6 (IL-6), interleukin 8 (IL-8), monocyte chemoattractant protein 1 (MCP-1), tumor necrosis factor alpha (TNFα), vascular endothelial growth factor (VEGF). Other laboratory parameters (C-reactive protein (CRP), ferritin, procalcitonin) were taken from patient records. Normality of distribution was assessed by the Shapiro-Wilk test. To compare groups, the Mann-Whitney test for independent samples, Wilcoxon test for dependent samples, and the Kruskal-Wallis test with Bonferroni correction for multiple comparisons were used.Results. In patients with sepsis and COVID-19 infection, no differences in the concentrations of cytokines, ferritin and CRP were found between the groups with detected and not detected virus by PCR test. Based on this, this group was considered homogeneous when studying the cytokine profile. It was shown that in patients with sepsis and COVID-19, significantly higher levels of sCD40L (p<0,0001) and VEGF (p=0,037) and relatively low levels of CRP (p<0,0001), IL-6 (p<0,0001), IL-8 (p<0,0001), TNFα (p<0,00058).Conclusion. These results indicate that sepsis in patients with COVID-19 courses with less elevation in inflammatory cytokine than in abdominal sepsis. At the same time, a critically high level of sCD40L indicates the significant endothelial damage.

Alzheimer's disease (AD) is the most common cause of dementia in the elderly. The aim of the work wasObjective: to determine the relationship between laboratory biomarkers in blood plasma and cerebrospinal fluid (CSF) in patients with AD and indicators of neuropsychological testing.Patients and methods. 52 patients with AD were examined, in which the concentration of 90 potential biomarkers were measured in blood plasma and CSF. Neuropsychological assessment included the Mini-Mental State Exam (MMSE), Frontal Assessment Battery (FAB), Montreal Cognitive Assessment (MoCA), and etc.Results and discussion. Correlations of different strength between the values of biomarkers in blood plasma and CSF and the results of neuropsychological assessment were revealed. A correlation was found between the soluble cell adhesion molecule (sICAM-1) in blood plasma and the largest number of neuropsychological tests sensitive to dementia stages (MoCA, MMSE, FAB) in patients with AD at the dementia stage. A correlation was found between the concentration of growth/differentiation factor 15 and interferon γ in blood plasma and FAB scores in patients with AD. The levels of granulocyte colony-stimulating factor (G-CSF) in CSF were associated with the dementia stage in AD, and the interleukin-1 receptor antagonist (IL-1RA) levels, on the contrary, with stages preceding the development of dementia in AD.Conclusion. sICAM-1 level in blood plasma, which is a marker of endothelial dysfunction, may be an indicator of the severity of the vascular neurodegenerative process in AD at the dementia stage. G-CSF in the CSF is associated with the dementia stage in AD, and IL-1RA – with the pre-dementia stage of AD, which determines the prospect of their further study as diagnostic markers.

Aim . To determine the reference ranges of concentrations of 38 cytokines, chemokines and growth factors, as well as to measure the content of these analytes in patients with neurodegenerative and cardiovascular diseases (CVDs) using biomaterial from the biobank repository. Material and methods . The study included 303 serum and plasma samples from 281 healthy donors, 242 samples from 224 patients with neurodegenerative diseases, and 164 samples from 152 patients with CVDs from the biobank of the of St. Petersburg City Hospital № 40. In all samples, the concentration of 38 cytokines, chemokines, and growth factors was determined by multiplex immunofluorescence assay. Results . Based on the measured concentrations in the group of healthy donors, non-parametric 95% reference ranges with 90% confidence intervals were calculated. For the majority of analytes, no sex and age differences were observed. In donors >65 years of age, the concentration of macrophage inflammatory protein-1-α was reduced and the levels of interleukin-8 and the chemokine interferon-inducible protein 10 were increased. Young donors (18-35 years) had lower levels of tumor necrosis factor-α. In groups with neurodegenerative and cardiovascular diseases, multiple deviations from the calculated reference values were found. Conclusion . Certain reference intervals are intended to evaluate the concentrations of cytokines, chemokines and growth factors determined in blood serum or plasma using Human Cytokine/Chemokine Magnetic Bead Panel 1 reagents (Merck, Millipore) on the MAGPIX system and do not imply a direct transfer to other analytical methods.

The course of COVID-19 is characterized by wide variability, with genetics playing a contributing role. Through large-scale genetic association studies, a significant link between genetic variants and disease severity was established. However, individual genetic variants identified thus far have shown modest effects, indicating a polygenic nature of this trait. To address this, a polygenic risk score (PRS) can be employed to aggregate the effects of multiple single nucleotide polymorphisms (SNPs) into a single number, allowing practical application to individuals within a population. In this work, we investigated the performance of a PRS model in the context of COVID-19 severity in 1,085 Russian participants using low-coverage NGS sequencing. By developing a genome-wide PRS model based on summary statistics from the COVID-19 Host Genetics Initiative consortium, we demonstrated that the PRS, which incorporates information from over a million common genetic variants, can effectively identify individuals at significantly higher risk for severe COVID-19. The findings revealed that individuals in the top 10% of the PRS distribution had a markedly elevated risk of severe COVID-19, with an odds ratio (OR) of 2.1 (95% confidence interval (CI): 1.4–3.2, p-value = 0.00046). Furthermore, incorporating the PRS into the prediction model significantly improved its accuracy compared to a model that solely relied on demographic information (p-value < 0.0001). This study highlights the potential of PRS as a valuable tool for identifying individuals at increased risk of severe COVID-19 based on their genetic profile.