Correlations of interleukin levels with the severity of SARS-CoV-2 coronavirus infection.

A new coronavirus infection caused by the SARS-CoV-2 virus is characterized by a systemic hyperinflammatory response with a pronounced increase in the content of pro-inflammatory cytokines. Materials and methods. The study was conducted on the basis of the Samara Regional Children's Infectious Diseases Hospital from 2021 to 2022. 40 patients with moderate (n = 20, group I) and severe forms (n = 20, group II) COVID-19 were studied, the comparison group consisted of patients with viral pneumonia of another etiology (n = 35, group III). Results. The infectious agent SARS-CoV-2 induces high levels of cytokines IL-6 (p < 0.005), IL-8 (p < 0.05) and a slight increase in TNF-alpha (p < 0.05). IL-8 was significantly associated with disease duration (p < 0.01). We assume that the value of this interleukin will increase in the post-COVID period. Conclusions. Changes in IL-6 and IL-8 levels in patients with COVID-19, along with clinical features, are important biomarkers for predicting the severity and duration of the disease.Copyright © Children Infections.All rights reserved

DYNAMICS IN MATURATION OF SARS-CoV-2 RBD-SPECIFIC IgG ANTIBODY AVIDITY DEPENDING ON IMMUNIZATION TIMEFRAME AND TYPE.

The aim is to examine dynamics of avidity maturation of IgG antibodies against SARS-CoV-2 RBD depending on the type of immunization (vaccination or infection), as well as on the duration and frequency of immunization. Materials and methods. The study was performed on two sample cohorts collected at two time points during COVID-19 pandemic. The first cohort (group No. 1) consisted of 87 samples of blood sera obtained from COVID-19 convalescents in the period from March to September 2020. The second cohort included 204 samples obtained in September 2021 from two patient groups. Group No. 2 (n = 64) - patients immunized with a full course of Gam-Covid-Vac, group No. 3 (n = 140) - COVID-19 convalescent patients and subjects vaccinated with Gam-Covid-Vac ("hybrid immunity"). Results and conclusion. The dynamics of avidity maturation for SARS-CoV-2 RBD IgG antibodies depending on the method and frequency of immunization, showed that the most effective immunity was formed in COVID-19 convalescent patients and subjects vaccinated with a full course of Gam-Covid-Vac. The "hybrid" immunity showed not only a significantly higher (compared with groups No. 1 and No. 2) level of IgG antibodies (median 228 BAU/ml vs 75 or 119 BAU/ml, p < 0.001), but also a higher level of avidity (IA 90.5% vs 54.5 and 76.6, respectively, p < 0.001, 4M urea). In the test for assessing the avidity index with the denaturing agent 8M urea in patients with "hybrid immunity", the median level of IA was 25% versus 14.8% and 16% in COVID-19 convalescents and vaccinated subjects (p < 0.001), only in 8 patients IA was higher than 50%. While comparing a single infection of COVID-19 with a full course of Gam-Covid-Vac, it was shown that vaccination leads to higher IgG levels (median values in groups 119 and 75 BAU/ml, p < 0.001) and to a higher avidity index (median 76.6% vs 54.5%). Thus, the more rapid induction of high-avidity antibodies was in vaccinated individuals at early stages of immunization (up to 4 months), during the period when IgG avidity maturation has not yet been completed. Our results showed that during this period vaccination leads to production of antibodies with avidity index at median level of 82% versus 36% in COVID-19 convalescents at similar time point.Copyright © 2023 Saint Petersburg Pasteur Institute. All rights reserved.

DYNAMICS IN MATURATION OF SARS-CoV-2 RBD-SPECIFIC IgG ANTIBODY AVIDITY DEPENDING ON IMMUNIZATION TIMEFRAME AND TYPE

The aim is to examine dynamics of avidity maturation of IgG antibodies against SARS-CoV-2 RBD depending on the type of immunization (vaccination or infection), as well as on the duration and frequency of immunization. Materials and methods. The study was performed on two sample cohorts collected at two time points during COVID-19 pandemic. The first cohort (group No. 1) consisted of 87 samples of blood sera obtained from COVID-19 convalescents in the period from March to September 2020. The second cohort included 204 samples obtained in September 2021 from two patient groups. Group No. 2 (n = 64) — patients immunized with a full course of Gam-Covid-Vac, group No. 3 (n = 140) — COVID-19 convalescent patients and subjects vaccinated with Gam-Covid-Vac ("hybrid immunity”). Results and conclusion. The dynamics of avidity maturation for SARS-CoV-2 RBD IgG antibodies depending on the method and frequency of immunization, showed that the most effective immunity was formed in COVID-19 convalescent patients and subjects vaccinated with a full course of Gam-Covid-Vac. The "hybrid” immunity showed not only a significantly higher (compared with groups No. 1 and No. 2) level of IgG antibodies (median 228 BAU/ml vs 75 or 119 BAU/ml, p < 0.001), but also a higher level of avidity (IA 90.5% vs 54.5 and 76.6, respectively, p < 0.001, 4M urea). In the test for assessing the avidity index with the denaturing agent 8M urea in patients with "hybrid immunity”, the median level of IA was 25% versus 14.8% and 16% in COVID-19 convalescents and vaccinated subjects (p < 0.001), only in 8 patients IA was higher than 50%. While comparing a single infection of COVID-19 with a full course of Gam-Covid-Vac, it was shown that vaccination leads to higher IgG levels (median values in groups 119 and 75 BAU/ml, p < 0.001) and to a higher avidity index (median 76.6% vs 54.5%). Thus, the more rapid induction of high-avidity antibodies was in vaccinated individuals at early stages of immunization (up to 4 months), during the period when IgG avidity maturation has not yet been completed. Our results showed that during this period vaccination leads to production of antibodies with avidity index at median level of 82% versus 36% in COVID-19 convalescents at similar time point. © 2023 Saint Petersburg Pasteur Institute. All rights reserved.

A modern view on the clinical value of the study of oral fluid in the practice of a pediatrician

Currently, the attention of the medical community to a non-invasive method of laboratory diagnostics-the study of oral fluid (oral, saliva, saliva test) in various fields of clinical medicine and mainly in adult patients has been updated. Saliva testing has shown good results, especially in the areas of genomics, microbiomics, proteomics, metabolomics, and transcriptomics. The review presents the possibilities of using a non-invasive method for infectious and non-infectious diseases in children. Saliva contains a wide range of protein DNA and RNA biomarkers that help detect many viral infections in children. Oral fluid tests for human immunodeficiency virus, hepatitis B virus have improved access to diagnostics for infants. Both serological and molecular analyzes of the oral fluid are suitable for routine examination and early detection of measles virus RNA, polyomaviruses. Angiotensin-converting enzyme-2 receptor expression was found in the saliva of children with COVID-19, which can be used to diagnose SARS-CoV-2. The saliva test is as effective as the standard test at identifying asymptomatic individuals in contact tracing. The possibilities of saliva diagnostics are positively assessed in transplantology. New biomarkers in saliva have been identified for the diagnosis of many somatic diseases in children. The role of oral fluid as an alternative to blood serum in patients with terminal renal failure, chronic kidney disease (determination of creatinine, urea) in both adults and children is shown. The data obtained may influence the recommendations for the treatment of patients. As a non-invasive method, the study of oral fluid is promising for the diagnosis, prognosis, monitoring of diseases, large-scale typing of children, and the search for new biomarkers. © 2022, Remedium Group Ltd. All rights reserved.

Newborns from women infected with COVID-19: somatic and metabolic status.

To date, there are limited data regarding manifestations of new coronavirus infection in infants born of SARS-CoV-2 infected mothers, so the aim of this study is to investigate somatic and metabolic status of newborn infants born to mothers diagnosed with COVID-19. The investigation was carried out on the bases of Laboratory Diagnostic Department of Samara Regional Clinical Hospital named after V.D. Seredavin and the Department of Fundamental and Clinical Biochemistry with Laboratory Diagnostics of Samara State Medical University. Under observation were 85 newborns, including 35 born of healthy mothers and 50 born of COVID-19 mothers.The somatic status of all newborns was assessed using the Apgar scale at the 1st and 5th minutes after birth. Also all newborns had general and biochemical blood tests and newborns from mothers with COVID-19 were tested for the presence of SARS-CoV-2 RNA in oral and nasopharyngeal swabs. Thus, the study of somatic status revealed that of 50 neonates from women infected with COVID-19, only 18% were practically healthy, the rest had signs of prematurity, hypotrophy, perinatal CNS damage, diabetic fetopathy, pulmonary atelectasis, delayed intrauterine development, asphyxia. The metabolic state is characterised by decreased haemoglobin and platelets, increased concentration of total protein, including C-reactive protein, high transaminase activity, decreased sodium and chloride content. These parameters of general and biochemical blood tests can be considered as indicators for the evaluation of the condition of newborns from mothers with COVID-19.

COVID-19 pandemic and kidney disease in children: literature review and own regional observations

Introduction. Currently, the coronavirus infection pandemic caused by the SARS-CoV-2 virus continues around the world. Research data from domestic and foreign authors indicate that the kidneys are a target organ for a new infection, lesions vary from pro-teinuria and hematuria to acute kidney injury. Aim of the study – to determine the frequency and nature of kidney damage in children with confirmed coronavirus infection. Materials and methods. A retrospective and prospective analysis of cases of confirmed COVID-19 infection in children (n = 441) admitted to the Samara Regional Children’s Infectious Diseases Hospital from March 2020 to July 2021 was carried out. SARS-CoV-2 RNA was detected in all patients by a one-step reverse transcription reaction combined with a polymerase chain reaction. The changes in the kidneys that occurred in 57 children were studied. The research results were processed using the Statistica 7.0 software (StatSoft, USA). Results. The involvement of the kidneys in the infectious process was detected in every 8 children with COVID-19 (12.9%), more often in the form of isolated urinary syndrome, the detection rate of which correlated with the severity of the course of corona-virus infection: in severe cases, proteinuria was detected in 31.6% of patients, hematuria – in 21%, acute kidney injury – in 10.5%, diabetic nephropathy – in 5.3%. Kidney damage was combined with damage to the respiratory and gastrointestinal tract, charac-terized by rapid recovery of urine output and azotemia parameters without special renal therapy. A clinical case of the onset of nephrotic syndrome that developed 2 weeks after suffering a coronavirus infection is described. Conclusions. Children with COVID-19 require kidney function monitoring for early detection and correction in case of impairment. Patients with isolated urinary syndrome in the acute period require long-term observation in order to detect latent renal pathology. © 2022, Remedium Group Ltd. All rights reserved.

PROINFLAMMATORY STATUS of ORAL FLUID in COVID-19

At present, a search for promising ways to diagnose infection caused by SARS-CoV-2 is quite relevant. Oral fluid is not commonly used for assessment of COVID-19 risk. Its molecular profile reflects both local state of the oral cavity, and individual organs and systems, thus suggesting a reliable diagnostic platform. Systemic inflammatory response is known to play a crucial role in development of the coronavirus infection;the “cytokine storm” determines severity of the disease. The saliva-based diagnostics of clinical course in COVID-19 patients includes determination of IL-6, IL-8, C-reactive protein in oral fluid, in order to assess severity of the inflammatory process. The present study was carried out at the Department of Fundamental and Clinical Biochemistry with Laboratory Diagnostics, and Department of Pediatric Infections at the Samara State Medical University. The study involved 122 persons: 67 clinically healthy individuals comprised the control group, and the group of comparison included 55 inpatients with moderate or severe coronavirus infection (COVID-19) caused by SARS-CoV-2 virus as confirmed by PCR and/or ELISA testing. Development of the disease was accompanied by drastically increased contents of IL-6 and IL-8 in oral fluid of the patients relative to the indexes in healthy persons, i.e., several-fold for IL-6 (+ 650%) and even higher elevation of IL-8 levels (+ 26513%), as well as a 2-fold increase of C-reactive protein (+115%). When comparing the immune indexes of oral fluid in presence versus absence of respiratory insufficiency, a significant difference was found for salivary IL-6 (+173%) in the patients with grade 1-2 respiratory insufficiency as compared with patients free of respiratory disorders. Determination of these proinflammatory markers in patients with COVID-19 is of important prognostic significance when assessing development of the disease and its severity. Direct detection of their content in the oral fluid makes this method relevant, and potentially demanded for the outpatient diagnostics, being highly important during pandemics of coronavirus infection and limited medical resources. Examination of oral fluid at the pre-hospital stage is a resource-saving technology, since it does not require additional medical staff to take biomaterial, is non-invasive to the patient, and suggesting a wide range of research items, it can resolve a number of diagnostic issues, e.c., presence of specific genetic material or antibodies to SARS-CoV-2, severity of the inflammatory process and the risk of respiratory failure in the patient.