Bronchial Asthma and COVID-19: Etiology, Pathological Triggers, and Therapeutic Considerations.

Bronchial asthma (BA) continues to be a difficult disease to diagnose. Various factors have been described in the development of BA, but to date, there is no clear evidence for the etiology of this chronic disease. The emergence of COVID-19 has contributed to the pandemic course of asthma and immunologic features. However, there are no unambiguous data on asthma on the background and after COVID-19. There is correlation between various trigger factors that provoke the development of bronchial asthma. It is now obvious that the SARS-CoV-2 virus is one of the provoking factors. COVID-19 has affected the course of asthma. Currently, there is no clear understanding of whether asthma progresses during or after COVID-19 infection. According to the results of some studies, a significant difference was identified between the development of asthma in people after COVID-19. Mild asthma and moderate asthma do not increase the severity of COVID-19 infection. Nevertheless, oral steroid treatment and hospitalization for severe BA were associated with higher COVID-19 severity. The influence of SARS-CoV-2 infection is one of the protective factors. It causes the development of severe bronchial asthma. The accumulated experience with omalizumab in patients with severe asthma during COVID-19, who received omalizumab during the pandemic, has strongly suggested that continued treatment with omalizumab is safe and may help prevent the severe course of COVID-19. Targeted therapy for asthma with the use of omalizumab may also help to reduce severe asthma associated with COVID-19. However, further studies are needed to prove the effect of omalizumab. Data analysis should persist, based on the results of the course of asthma after COVID-19 with varying degrees of severity.

Are Endomyocardial Ventricular Biopsies Useful for Assessing Myocardial Fibrosis?

Myocardial fibrosis is an important factor in the progression of cardiovascular diseases. However, there is still no universal lifetime method of myocardial fibrosis assessment that has a high prognostic significance. The aim of the study was to determine the significance of ventricular endomyocardial biopsies for the assessment of myocardial fibrosis and to identify the severity of myocardial fibrosis in different cardiovascular diseases. Material and Methods: Endomyocardial biopsies (EMBs) of 20 patients with chronic lymphocytic myocarditis (CM), endomyocardial fragments obtained during septal reduction of 21 patients with hypertrophic cardiomyopathy (HCM), and 36 patients with a long history of hypertensive and ischemic heart disease (HHD + IHD) were included in the study. The control group was formed from EMBs taken on 12-14 days after heart transplantation (n = 28). Also, for one patient without clinical and morphological data for cardiovascular pathology, postmortem myocardial fragments were taken from typical EMB and septal reduction sites. The relative area of fibrosis was calculated as the ratio of the total area of collagen fibers to the area of the whole biopsy. Endocardium and subendocardial fibrosis were not included in the total biopsy area. Results: The relative fibrosis area in the EMBs in the CM patient group was 5.6 [3.3; 12.6]%, 11.1 [6.6; 15.9]% in the HHD + IHD patient group, 13.4 [8.8; 16.7]% in the HCM patient group, and 2.7 [1.5; 4.6]% in the control group. When comparing the fibrosis area of the CM patients in repeat EMBs, it was found that the fibrosis area in the first EMBs was 7.6 [4.8; 12.0]%, and in repeat EMBs, it was 5.3 [3.2; 7.6]%. No statistically significant differences were found between the primary and repeat EMBs (p = 0.15). In ROC analysis, the area of fibrosis in the myocardium of 1.1% (or lower than one) was found to be highly specific for the control group of patients compared to the study patients. Conclusions: EMB in the assessment of myocardial fibrosis has a questionable role because of the heterogeneity of fibrotic changes in the myocardium.

Tuberculosis disease in immunocompromised children and adolescents: a pTBnet multi-centre case-control study.

BACKGROUND: In high-resource settings the survival of immunocompromised (IC) children has increased and immunosuppressive therapies are increasingly being used. This study aimed to determine the clinical characteristics, performance of diagnostic tools and outcome of IC children with TB in Europe. METHODS: Multicentre, matched case-control study within the Paediatric Tuberculosis Network European Trials Group (ptbnet), capturing TB cases <18 years diagnosed 2000-2020. RESULTS: 417 TB cases were included, comprising 139 children with IC (HIV, inborn errors of immunity, drug-induced immunosuppression and other immunocompromising conditions) and 278 non-IC children as controls. Non-respiratory TB was more frequent among cases than controls (32.4% vs. 21.2%; p = 0.013). IC patients had an increased likelihood of presenting with severe disease (57.6% vs. 38.5%; p < 0.001; OR [95% CI]: 2.073 [1.37-3.13]). Children with IC had higher rates of false-negative tuberculin skin test (31.9% vs. 6.0%; p < 0.001) and QuantiFERON-TB Gold assay (30.0% vs. 7.3%; p < 0.001) results at diagnosis. Overall, the microbiological confirmation rate was similar in IC and non-IC cases (58.3% vs. 49.3%; p = 0.083). Although the mortality in IC children was <1%, the rate of long-term sequelae was significantly higher than in non-IC cases (14.8% vs. 6.1%; p = 0.004). CONCLUSIONS: IC children with TB disease in Europe have increased rates of non-respiratory TB, severe disease, and long-term sequelae. Immune-based TB tests have poor sensitivity in those children. Future research should focus on developing improved immunological TB tests that perform better in IC patients, and determining the reasons for the increased risk of long-term sequelae, with the aim to design preventive management strategies.

COVID-19 and Tuberculosis: Mathematical Modeling of Infection Spread Taking into Account Reduced Screening.

The COVID-19 pandemic resulted in the cessation of many tuberculosis (TB) support programs and reduced screening coverage for TB worldwide. We propose a model that demonstrates, among other things, how undetected cases of TB affect the number of future M. tuberculosis (M. tb) infections. The analysis of official statistics on the incidence of TB, preventive examination coverage of the population, and the number of patients with bacterial excretion of M. tb in the Russian Federation from 2008 to 2021 is carried out. The desired model can be obtained due to the fluctuation of these indicators in 2020, when the COVID-19 pandemic caused a dramatic reduction in TB interventions. Statistical analysis is carried out using R v.4.2.1. The resulting model describes the dependence of the detected incidence and prevalence of TB with bacterial excretion in the current year on the prevalence of TB with bacterial excretion in the previous year and on the coverage of preventive examinations in the current and previous years. The adjusted coefficient of model determination (adjusted R-squared) is 0.9969, indicating that the model contains almost no random component. It clearly shows that TB cases missed due to low screening coverage and left uncontrolled will lead to a significant increase in the number of new infections in the future. We may conclude that the obtained results clearly demonstrate the need for mass screening of the population in the context of the spread of TB infection, which makes it possible to timely identify patients with TB with bacterial excretion.

Assessment of Comorbidity in Patients with Drug-Resistant Tuberculosis.

A wide range of comorbidities, especially in multidrug-resistant tuberculosis (MDR-TB) and extensively drug-resistant tuberculosis (XDR-TB) patients, markedly complicates selecting effective treatment of tuberculosis (TB) and preventing the development of adverse events. At present, it is impossible to assess the severity of comorbid pathologies and develop indications for the administration of accompanying therapy in TB patients. The aim of this study was to identify the difference in the range of comorbidities between patients with MDR-TB and XDR-TB and assess the impact of comorbidities on TB treatment. Materials and Methods: A retrospective, prospective study was conducted where 307 patients with MDR-TB and XDR-TB pulmonary tuberculosis aged 18 to 75 years who received eTB treatment from 2016 to 2021 in St. Petersburg hospitals were analyzed. The analysis showed that the comorbidity level in MDR-TB and XDR-TB patients with TB treatment success and treatment failure was comparable with the use of the Charlson Comorbidity Index (CCI). The CCI demonstrated declining data in terms of TB treatment outcome period in both groups. A slight predominance of CCI score (3 to 4 points) in XDR-TB (22.7%) vs. MDR-TB (15.4%) patients was found. In the case of an TB treatment failure, the CCI level in MDR-TB vs. XDR-TB patients was characterized by a significantly higher rate of low magnitude (ranging from 1 to 2 points) in 21.1% vs. 4.5% (p < 0.05), which was higher in XDR-TB patients (ranging from 4 to 5 points, in 10.0% vs. 0, χ2 = 33.7 (p < 0.01)). Chronic viral hepatitis B and C infection, cardiovascular pathology, chronic obstructive pulmonary disease, and chronic alcoholism were found to be significant comorbidity factors that influenced the TB treatment success. Conclusions: It is evident that XDR-TB patients comprise a cohort with the most severe disease course due to comorbidities impacting TB treatment efficacy. The obtained data pointed to the need to determine comorbidity severity in patients with drug-resistant Mbt prior to administering TB treatment schemes.

Expression of Cytoskeletal Proteins (GFAP, Vimentin), Proapoptotic Protein (Caspase-3) and Protective Protein (S100) in the Epileptic Focus in Adults and Children with Drug-Resistant Temporal Lobe Epilepsy Associated with Focal Cortical Dysplasia.

The European Commission of the International League Against Epilepsy (ILAE) has identified glial mechanisms of seizures and epileptogenesis as top research priorities. The aim of our study was to conduct a comparative analysis of the expression levels of cytoskeletal proteins (glial fibrillar acidic protein (GFAP) and vimentin), protective protein S100, and proapoptotic caspase-3 protein in patients with drug-resistant epilepsy (DRE) associated with focal cortical dysplasia (FCD). We aimed to investigate how the expression levels of these proteins depend on age (both in children and adults), gender, and disease duration, using immunohistochemistry. Nonparametric statistical methods were employed for data analysis. In the epileptic focus area of the cortex and white matter in patients with FCD-associated temporal lobe DRE, a higher level of expression of these proteins was observed. Age and gender differences were found for vimentin and S100. In the early stages of disease development, there was a compensatory sequential increase in the expression of cytoskeletal and protective proteins. In patients with DRE, depending on the disease duration, patterns of development of neurodegeneration were noted, which is accompanied by apoptosis of gliocytes. These results provide insights into epilepsy mechanisms and may contribute to improving diagnostic and treatment approaches.

High Risk of Heart Tumors after COVID-19.

An emergence of evidence suggests that severe COVID-19 is associated with an increased risk of developing breast and gastrointestinal cancers. The aim of this research was to assess the risk of heart tumors development in patients who have had COVID-19. METHODS: A comparative analysis of 173 heart tumors was conducted between 2016 and 2023. Immunohistochemical examination with antibodies against spike SARS-CoV-2 was performed on 21 heart tumors: 10 myxomas operated before 2020 (the control group), four cardiac myxomas, one proliferating myxoma, three papillary fibroelastomas, two myxofibrosarcomas, one chondrosarcoma resected in 2022-2023. Immunohistochemical analysis with antibodies against CD34 and CD68 was also conducted on the same 11 Post-COVID period heart tumors. Immunofluorescent examination with a cocktail of antibodies against spike SARS-CoV-2/CD34 and spike SARS-CoV-2/CD68 was performed in 2 cases out of 11 (proliferating myxoma and classic myxoma). RESULTS: A 1.5-fold increase in the number of heart tumors by 2023 was observed, with a statistically significant increase in the number of myxomas. There was no correlation with vaccination, and no significant differences were found between patients from 2016-2019 and 2021-2023 in terms of gender, age, and cardiac rhythm dis-orders. Morphological examination revealed the expression of spike SARS-CoV-2 in tumor cells, endothelial cells, and macrophages in 10 out of 11 heart tumors. CONCLUSION: The detection of SARS-CoV-2 persistence in endothelium and macrophages as well as in tumor cells of benign and malignant cardiac neoplasms, the increase in the number of these tumors, especially cardiac myxomas, after the pandemic by 2023 may indicate a trend toward an increased risk of cardiac neoplasms in COVID-19 patients, which re-quires further research on this issue and a search for new evidence.

A Key Role of CD8+ T Cells in Controlling of Tuberculosis Infection.

The main role in the control of tuberculosis infection is played by macrophages and Th1 and CD8+ T cells. The study aimed to identify the most diagnostically significant CD8+ T cell subsets in tuberculosis patients. METHODS: Peripheral blood samples from patients with clinical, radiological, and bacteriologically confirmed pulmonary tuberculosis (TB, n = 32) and healthy subjects (HC, n = 31) were collected and analyzed using 10-color flow cytometry. RESULTS: The frequency of the EM4 CD3+CD8+ cells was reduced in the peripheral blood of patients with pulmonary tuberculosis, while the relative and absolute number of EM1 CD3+CD8+ cells increased compared to the control group. CD57 expression was reduced in patients with pulmonary tuberculosis on EM1, EM2, and pE1 CD3+CD8+ cells, whereas the EM3 cells had a high level of CD57 expression. The relative and absolute number of Tc2 (CCR6-CXCR3-) cells in peripheral blood in patients with pulmonary tuberculosis was increased, while the frequency of Tc1 (CCR6-CXCR3+) was decreased, compared to healthy donors. CONCLUSIONS: Patients with pulmonary tuberculosis have an abnormal CD3+CD8+ cell profile and demonstrate their impaired maturation and functional activity.

Tuberculosis and COVID-19 Dually Affect Human Th17 Cell Immune Response.

COVID-19 infection not only profoundly impacts the detection of tuberculosis infection (Tbc) but also affects modality in tuberculosis patient immune response. It is important to determine immune response alterations in latent tuberculosis infection as well as in SARS-CoV-2-infected tuberculosis patients. Such changes may have underlying effects on the development and course of further tuberculosis. Here, we aimed to review the characteristics of immune response in TB patients or convalescent COVID-19 patients with latent TB infection (LTBI). MATERIALS AND METHODS: We analyzed the features of immune response in tuberculosis and COVID-19 patients. For this, we analyzed publications released from December 2019 to March 2023; those which were published in accessible international databases ("Medline", "PubMed", "Scopus") and with keywords such as "COVID-19", "SARS-CoV-2", "tuberculosis", "pulmonary tuberculosis", "latent tuberculosis infection", "Treg", "follicular Treg", and "Treg subsets", we considered. RESULTS: Through our analysis, we found that tuberculosis patients who had been infected with COVID-19 previously and elevated Th1 and Th2 cell levels. High levels of Th1 and Th2 cells may serve as a positive marker, characterizing activated immune response during TB infection. COVID-19 or post-COVID-19 subjects showed decreased Th17 levels, indicating a lack of tuberculosis development. Moreover, the typical course of tuberculosis is associated with an increase in Treg level, but COVID-19 contributes to a hyperinflammatory response. CONCLUSION: According to the data obtained, the course of tuberculosis proceeds in a dissimilar way due to the distinct immune response, elicited by SARS-CoV-2. Importantly, the development of active tuberculosis with a severe course is associated with a decline in Treg levels. Both pathogens lead to disturbed immune responses, increasing the risk of developing severe TB. The insights and findings of this paper may be used to improve the future management of individuals with latent and active tuberculosis.

Features of Myocarditis: Morphological Differential Diagnosis in Post-COVID-19 Children.

Myocarditis is characterized by dysfunction and destruction of cardiomyocytes, infiltrative inflammation, and development of fibrosis. Late diagnosis of myocarditis has been a serious global health problem, especially due to the spread of a new coronavirus infection. The aim of this review is to identify differences between myocarditis of viral etiology, including SARS-CoV-2 lesions, based on instrumental and pathomorphological findings. MATERIAL AND METHODS: We analyzed publications covering the period from December 2019 to May 2023, published in publicly accessible international databases ("Medline", "PubMed", "Scopus"), with queries for the keywords "myocarditis", "children", "cardiovascular inflammation", "COVID-19", "SARS-CoV-2", "severe acute respiratory syndrome coronavirus 2", "differential diagnosis". RESULTS: It was found that no unambiguous morphological criteria for the diagnosis of myocarditis coupled to SARS-CoV-2 lesions were identified. However, the detected histopathological changes such as virus-associated degeneration, apoptosis, cardiomyocyte necrosis, moderate interstitial hyperemia, myocardial tissue oedema, and capillary endothelial cell dysfunction were the major markers of SARS-CoV-2 infection. CONCLUSION: It is necessary further reconsider morphological criteria to diagnose SARS-CoV-2-caused myocarditis, rather than solely relying on detecting viral RNA by PCR as the sole evidence-based criterion. Similar issues accompany diagnostics of myocardial lesions associated with other viral infections. Evidence for an etiological diagnosis of myocarditis can be provided by a comprehensive analysis of the diagnostic criteria obtained, confirming virus exposure, followed by development of distinct clinical symptoms, MRI and CT changes, and morphological criteria.

New Scenarios in Heart Transplantation and Persistency of SARS-CoV-2 (Case Report).

Heart transplantation is a treatment of choice for patients with severe heart failure. Infection transmission from a donor to a recipient remains a prominent problem in organ transplantation. However, the risk of SARS-CoV-2 transmission in nonlung organ transplantation is still unclear. In this article we presented a case of a 28-year-old pregnant woman who developed heart failure soon after recovery from a SARS-CoV-2 infection in the third trimester of gestation. In the postpartum period, the heart disease worsened and the patient required cardiac transplantation. We examined the recipient's heart and made a diagnosis of left ventricular noncompaction cardiomyopathy. Immunohistochemical analysis showed SARS-CoV-2 antigen expression in the donor's heart before transplantation, and after the transplantation, an endomyocardial biopsy was taken. Moreover, an ultrastructural assessment of the endomyocardial specimen revealed endothelial and pericyte injury and a single particle on the surface of the endothelium consistent with SARS-CoV-2 viral particles. Recent findings in the literature associated these damages with SARS-CoV-2 infection. The present study describes the rare case of SARS-CoV-2 transmission from donor to postpartum recipient through a heart transplant and demonstrates the importance of endomyocardial biopsy before and after heart transplantation.

Morphological Changes in the Myocardium of Patients with Post-Acute Coronavirus Syndrome: A Study of Endomyocardial Biopsies.

The clinical manifestation study of post-acute sequelae of SARS-CoV-2 infection (PASC) has shown a lack of knowledge regarding its morphology and pathogenesis. The aim of this research was to investigate morphological manifestations of PASC in the myocardium. MATERIALS AND METHODS: The study included 38 patients requiring endomyocardial biopsy (EMB) during the post-acute phase of coronavirus infection and a control group including patients requiring EMB prior to the SARS-CoV-2 pandemic. The patients' clinical and laboratory data were analyzed. Histological examination and immunohistochemistry (IHC) of the myocardial tissue was conducted with antibodies to CD3, CD68, HLA-DR, MHC1, C1q, VP1 enteroviruses, spike protein SARS-CoV-2, Ang1, von Willebrand factor (VWF), and VEGF. The morphometric analysis included counting the mean number of inflammatory infiltrate cells per mm2 and evaluating the expression of SARS-CoV-2 spike protein, HLA-DR, MHC1, C1q, Ang1, VWF, and VEGF using a scoring system. If the expression of SARS-CoV-2 spike protein was >3 points, an additional IHC test with antibodies to ACE2, CD16 as well as RT-PCR testing of the myocardial tissue were performed. For two patients, immunofluorescence tests of the myocardial tissue were performed using antibody cocktails to SARS-CoV-2 spike protein/CD16, SARS-CoV-2 spike protein/CD68, CD80/CD163. The statistical data analysis was carried out using the Python programming language and libraries such as NumPy, SciPy, Pandas, and Matplotlib. RESULTS: The study demonstrated a significant increase in the number of CD68+ macrophages in the myocardium of PASC patients compared to patients who did not have a history of COVID-19 (p = 0.014 and p = 0.007 for patients with and without myocarditis, respectively), predominantly due to M2 macrophages. An increase in the number of CD68+ macrophages was more frequently observed in patients with shorter intervals between the most recent positive SARS-CoV-2 PCR test and the time of performing the EMB (r = -0.33 and r = -0.61 for patients with and without myocarditis, respectively). The expression scores of Ang1, VEGF, VWF, and C1q in PASC patients did not significantly differ from those in EMB samples taken before 2019. CONCLUSION: The myocardium of PASC patients demonstrated a significant increase in the number of CD68+ macrophages and a decrease in the expression of markers associated with angiopathy. No evidence of coronavirus-associated myocarditis was observed in any PASC patient.

Circulating Regulatory T Cell Subsets in Patients with Sarcoidosis.

Over recent years, many researchers have supported the autoimmune theory of sarcoidosis. The presence of uncontrolled inflammatory response on local and system levels in patients with sarcoidosis did not define that the immunoregulatory mechanisms could be affected. The aim of this study was to evaluate the distribution and the disturbance circulating Treg cell subsets in the peripheral blood in patients with sarcoidosis. MATERIALS AND METHODS: A prospective comparative study was performed in 2016-2018 (34 patients with sarcoidosis (men (67.6%), women (32.3%)) were examined). Healthy subjects-the control group (n = 40). The diagnosis of pulmonary sarcoidosis was performed according to the standard criteria. We used two ten-color combinations of antibodies for Treg immunophenotyping. The first one contained CD39-FITC, CD127-PE, CCR4-PE/Dazzle™ 594, CD25-PC5.5, CD161-PC7, CD4-APC, CD8-APC-AF700, CD3-APC/Cy7, HLA-DR-PacBlue, and CD45 RA-BV 510™, while the second consisted of CXCR3-Alexa Fluor 488, CD25-РЕ, CXCR5-РЕ/Dazzle™ 594, CCR4-PerСP/Сy5.5, CCR6-РЕ/Cy7, CD4-АPC, CD8 АPC-AF700, CD3-АPC/Cy7, CCR7-BV 421, and CD45 RA-BV 510. The flow cytometry data were analyzed by using Kaluza software v2.3. A statistical analysis was performed with Statistica 7.0 and GraphPad Prism 8 software packages. RESULTS OF THE STUDY: Primarily, we found that patients with sarcoidosis had decreased absolute numbers of Treg cells in circulation. We noted that the level of CCR7-expressing Tregs decreased in patients with sarcoidosis vs. the control group (65.55% (60.08; 70.60) vs. 76.93% (69.59; 79.86) with p < 0.001). We noticed that the relative numbers of CD45RA-CCR7+ Tregs decreased in patients with sarcoidosis (27.11% vs. 35.43%, p < 0.001), while the frequency of CD45 RA-CCR7- and CD45RA+ CCR7- Tregs increased compared to the control group (33.3% vs. 22.73% and 0.76% vs. 0.51% with p < 0.001 and p = 0.028, respectively). CXCR3-expressing Treg cell subsets-Th1-like CCR60078CXCR3+ Tregs and Th17.1-like CCR6+ CXCR3+ Tregs-significantly increased in patients with sarcoidosis vs. the control group (14.4% vs. 10.5% with p < 0.01 and 27.9% vs. 22.8% with p < 0.01, respectively). Furthermore, the levels of peripheral blood EM Th17-like Tregs significantly decreased in the sarcoidosis group vs. the control group (36.38% vs. 46.70% with p < 0.001). Finally, we found that CXCR5 expression was increased in CM Tregs cell subsets in patients with sarcoidosis. CONCLUSIONS: Our data indicated a decrease in circulating Tregs absolute numbers and several alterations in Treg cell subsets. Moreover, our results highlight the presence of increased levels of CM CXCR5+ follicular Tregs in the periphery that could be linked with the imbalance of follicular Th cell subsets and alterations in B cell, based on the immune response. The balance between the two functionally distinct Treg cell populations-Th1-like and Th17-like Tregs-could be used in sarcoidosis diagnosis and the determination of prognosis and disease outcomes. Furthermore, we want to declare that analysis of Treg numbers of phenotypes could fully characterize their functional activity in peripherally inflamed tissues.

Sarcoidosis and Autoimmune Inflammatory Syndrome Induced by Adjuvants.

Currently, sarcoidosis remains one of the diseases with unknown etiology, which significantly complicates its diagnosis and treatment. Various causes of sarcoidosis have been studied for many years. Both organic and inorganic trigger factors, provoking the development of granulomatous inflammation are considered. However, the most promising and evidence-based hypothesis is the development of sarcoidosis as an autoimmune disease, provoked by various adjuvants in genetic predisposed individuals. This concept fits into the structure of the autoimmune/inflammatory syndrome, induced by adjuvants (ASIA) that was proposed in 2011 by Professor Shoenfeld Y. In this paper, the authors reveal the presence of major and minor ASIA criteria for sarcoidosis, propose a new concept of the course of sarcoidosis within the framework of ASIA, and point out the difficulties in creating a model of the disease and the selection of therapy. It is obvious that the data obtained not only bring us closer to understanding the nature of sarcoidosis, but also potentiate new studies confirming this hypothesis by obtaining a model of the disease.

Severe Course of COVID-19 and Long-COVID-19 in Children: Difficulties in Diagnosis.

The question of COVID-19 and long-COVID-19 course in children remains unsolved. This infection in children, which is associated with COVID-19, can vary from asymptomatic to systemic damage of various systems. Multisystem inflammatory syndrome in children, associated with SARS-CoV-2 (MIS-C), is a serious condition in children and adolescents after experiencing COVID-19. Published data on MIS-C have indicated that the inflammation can be registered in the gastrointestinal tract (60-100%), as well as in cardiovascular (80%), nervous (29-58%), and respiratory (21-65%) systems. However, with the changing characteristics of SARS-CoV-2, the manifestations of COVID-19 and long-COVID-19 in children have also been changing. Currently, there is no clear understanding of the development of severe COVID-19 and MIS-C in children, especially after being exposed to patients with COVID-19. We presented two new clinical courses of multisystem inflammatory syndrome in children with severe multisystem damage after close contact to relatives with COVID-19 or long-COVID-19. Thus, high-risk children, who are positive for SARS-CoV-2 infection after contact with COVID-19 patients, should be clinically managed during the first few months. The identification of the disease complexity requires the involvement of neurologists, cardiologists, and other specialists.

Tuberculosis in the Russian Federation: Prognosis and Epidemiological Models in a Situation After the COVID-19 Pandemic.

AIM: Because of the COVID-19 pandemic, many support programs for tuberculosis (TB) patients have been discontinued and TB mass screening activities decreased worldwide, resulting in a decrease in new case detection and an increase in TB deaths (WHO, WHO global lists of high burden countries for TB, multidrug/rifampicin-resistant TB (MDR/RR-TB) and TB/HIV, 2021-2025, 2021). The study aimed to assess changes in epidemiological indicators of tuberculosis in the Russian Federation and to simulate these indicators in the post-COVID-19 period. MATERIALS AND METHODS: The main epidemiological indicators of tuberculosis were analyzed with the use of government statistical data for the period from 2009 to 2021. Further mathematical modeling of epidemiological indicators for the coming years was carried out, taking into account the TB screening by chest X-ray. Statistical analysis was carried out using the software environment R (v.3.5.1) for statistical computing and the commercial software Statistical Package for the Social Sciences (SPSS Statistics for Windows, version 24.0, IBM Corp., 2016). Time series forecasting was performed using the programming language for statistical calculations R, version 4.1.2 and the bsts package, version 0.9.8. STUDY RESULTS: The study has found that the mean regression coefficient of a single predictor differs in the model for TB incidence and mortality (0.0098 and 0.0002, respectively). Forecast of overall incidence, the incidence of children and the forecast for mortality using the basic scenario (screening 75-78%) for the period from 2022 to 2026 was characterized by a mean decrease rate of 23.1%, 15.6% and 6.0% per year, respectively. A conservative scenario (screening 47-63%) of overall incidence indicates that the incidence of children and the forecast for mortality will continue to decrease with a mean decrease rate of 23.2%, 15.6% and 6.0% per year, respectively. Comparable data were obtained from the forecast of overall incidence, the incidence of children and the forecast for mortality using the optimistic scenario (screening 82-89%) with a mean decrease rate of 22.9%, 15.4% and 6.0% per year, respectively. CONCLUSIONS: It has been proven that the significance of screening with chest X-ray as a predictor of mortality is minimal. However, TB screening at least 60% of the population (chest X-ray in adults and immunological tests in children) have provided relationship between the TB screening rate and TB mortality rate (TB mortality rate increases with an increase in the population coverage and, conversely, decreases with a decrease in the population coverage).

COVID-19 Heart Lesions in Children: Clinical, Diagnostic and Immunological Changes.

In the beginning of COVID-19, the proportion of confirmed cases in the pediatric population was relatively small and there was an opinion that children often had a mild or asymptomatic course of infection. Our understanding of the immune response, diagnosis and treatment of COVID-19 is highly oriented towards the adult population. At the same time, despite the fact that COVID-19 in children usually occurs in a mild form, there is an incomplete understanding of the course as an acute infection and its subsequent manifestations such as Long-COVID-19 or Post-COVID-19, PASC in the pediatric population, correlations with comorbidities and immunological changes. In mild COVID-19 in childhood, some authors explain the absence of population decreasing T and B lymphocytes. Regardless of the patient's condition, they can have the second phase, related to the exacerbation of inflammation in the heart tissue even if the viral infection was completely eliminated-post infectious myocarditis. Mechanism of myocardial dysfunction development in MIS-C are not fully understood. It is known that various immunocompetent cells, including both resident inflammatory cells of peripheral tissues (for example macrophages, dendritic cells, resident memory T-lymphocytes and so on) and also circulating in the peripheral blood immune cells play an important role in the immunopathogenesis of myocarditis. It is expected that hyperproduction of interferons and the enhanced cytokine response of T cells 1 and 2 types contribute to dysfunction of the myocardium. However, the role of Th1 in the pathogenesis of myocarditis remains highly controversial. At the same time, the clinical manifestations and mechanisms of damage, including the heart, both against the background and after COVID-19, in children differ from adults. Further studies are needed to evaluate whether transient or persistent cardiac complications are associated with long-term adverse cardiac events.

Performance of QuantiFERON-TB Gold Plus assays in paediatric tuberculosis: a multicentre PTBNET study.

RATIONALE: In 2016, a new interferon-gamma release assay (IGRA) was introduced, QuantiFERON-TB Gold Plus (QFT-Plus), claimed to have improved sensitivity in active tuberculosis (TB). OBJECTIVES: This study aimed to determine the performance of QFT-Plus, compared with previous generation IGRAs and the tuberculin skin test (TST), in children with TB in Europe. METHODS: Multicentre, ambispective cohort study within the Paediatric Tuberculosis Network European Trials Group (ptbnet), a dedicated paediatric TB research network comprising >300 members, capturing TB cases <18 years-of-age diagnosed between January 2009 and December 2019. MEASUREMENTS AND MAIN RESULTS: 1001 TB cases from 16 countries were included (mean age (IQR) 5.6 (2.4-12.1) years). QFT-Plus was performed in 358, QFT Gold in-Tube (QFT-GIT) in 600, T-SPOT.TB in 58 and TST in 636 cases. The overall test sensitivities were: QFT-Plus 83.8% (95% CI 80.2% to 87.8%), QFT-GIT 85.5% (95% CI 82.7% to 88.3%), T-SPOT.TB 77.6% (95% CI 66.9% to 88.3%) and TST (cut-off ≥10 mm) 83.3% (95% CI 83.3% to 86.2%). There was a trend for tests to have lower sensitivity in patients with miliary and/or central nervous system (CNS) TB (73.1%, 70.9%, 63.6% and 43.5%, respectively), and in immunocompromised patients (75.0%, 59.6%, 45.5% and 59.1%, respectively). CONCLUSIONS: The results indicate that the latest generation IGRA assay, QFT-Plus, does not perform better than previous generation IGRAs or the TST in children with TB disease. Overall, tests performed worse in CNS and miliary TB, and in immunocompromised children. None of the tests evaluated had sufficiently high sensitivity to be used as a rule-out test in children with suspected TB.

Sarcoidosis-related autoimmune inflammation in COVID-19 convalescent patients.

Currently, there are a large number of reports about the development of autoimmune conditions after COVID-19. Also, there have been cases of sarcoid-like granulomas in convalescents as a part of the post-COVID-19 syndrome. Since one of the etiological theories of sarcoidosis considers it to be an autoimmune disease, we decided to study changes in the adaptive humoral immune response in sarcoidosis and SARS-CoV-2 infection and to find out whether COVID-19 can provoke the development of sarcoidosis. This review discusses histological changes in lymphoid organs in sarcoidosis and COVID-19, changes in B cell subpopulations, T-follicular helper cells (Tfh), and T-follicular regulatory cells (Tfr), and analyzes various autoantibodies detected in these pathologies. Based on the data studied, we concluded that SARS-CoV-2 infection may cause the development of autoimmune pathologies, in particular contributing to the onset of sarcoidosis in convalescents.

Efficacy of Tuberculosis Treatment in Patients with Drug-Resistant Tuberculosis with the Use of Bedaquiline: The Experience of the Russian Federation.

In the conditions of the continued growth of multiple- and extensive drug-resistant tuberculosis, use of the new highly effective anti-tuberculosis drugs in this patient category is of great relevance. The aim of the study was determination the efficacy of treatment in patients with multidrug- and extensive drug-resistant tuberculosis using bedaquiline based on studies published in the Russian Federation. MATERIALS AND METHODS: The authors analyzed data published in studies from 2014 to 2022; 41 publications were included in total and 17 articles corresponded to the study design. The results of treatment of 1404 tuberculosis patients with MDR/XDR TB were described. Bedaquiline was used according to the standard scheme with a description of the treatment results after 24-26 weeks. Treatment efficacy was estimated according to accepted criteria. RESULTS OF THE STUDY: The analysis showed that the treatment efficacy on conversion was achieved in 79.5% of cases (95% Cl 76.5-82.3), and recovery was observed in 82.0% of cases (95% Cl 78.6-85.1). Departure from the therapy was observed in rare cases (9.8%; 95% Cl 7.9-12.2). Deaths were recorded in 6.5% of cases (95% Cl 4.9-8.3), which were associated with the severe disease and concomitant pathology in 74.3%. The development of adverse events was noted in half of the patients (55.7%); however, bedaquiline cancellation occurred in a few cases (7.0%; 95% Cl 3.0-13.0). From analyzing data in patients with MDR and XDR TB, the efficacy of treatment was 89.9% (95% Cl 85.9-93.2) and 71.9% (95% Cl 66.2-77.1), respectively. CONCLUSION: Use of bedaquiline in treatment makes it possible to achieve recovery of patients with MDR/XDR TB in 82.0% of cases with patients dropping out of treatment in 9.8%. At the same time, in patients with MDR TB, recovery was achieved in 89.9% of cases, while in patients with XDR TB, 71.9% of cases recovered.