Current scenario of COVID-19 in pediatric age group and physiology of immune and thymus response

SARS-CoV-2 Infection in Venezuelan Pediatric Patients-A Single Center Prospective Observational Study

Several studies suggest that children infected with SARS-CoV-2 have fewer clinical manifestations than adults; when they develop symptoms, they rarely progress to severe disease. Different immunological theories have been proposed to explain this phenomenon. In September 2020, 16% of the active COVID-19 cases in Venezuela were children under 19 years. We conducted a cross-sectional study of pediatric patients' immune response and clinical conditions with SARS-CoV-2 infection. The patients were admitted to the COVID-19 area of the emergency department of Dr José Manuel de los Ríos Children's Hospital (2021-2022). The lymphocyte subpopulations were analyzed by flow cytometry, and IFNγ, IL-6, and IL-10 serum concentrations were quantified using commercial ELISA assays. The analysis was conducted on 72 patients aged one month to 18 years. The majority, 52.8%, had mild disease, and 30.6% of the patients were diagnosed with MIS-C. The main symptoms reported were fever, cough, and diarrhea. A correlation was found between IL-10 and IL-6 concentrations and age group, lymphocyte subpopulations and nutritional status and steroid use, and IL-6 concentrations and clinical severity. The results suggest a different immune response depending on age and nutritional status that should be considered for treating pediatric COVID-19 patients.

Dynamic zero-COVID strategy in controlling COVID-19 in Shanghai, China: A cost-effectiveness analysis

BACKGROUND

The sustainability and generalizability of China's dynamic zero-COVID strategy on eliminating SARS-CoV-2 transmission has casted doubt globally, mainly because it has exacted high social and economic cost. This study aimed to estimate the disease burden during the first wave of Omicron in China and compared the cost-effectiveness of implementing a Real-world strategy (adjusted dynamic zero-COVID strategy) with two simulated strategies (routine and stricter dynamic zero-COVID strategy) to inform appropriate strategies for COVID-19 pandemic control.

METHODS

A dynamic state-transition simulation model was developed to compare the health and cost outcomes between different dynamic zero-COVID strategies. Omicron-related healthcare costs were estimated from the societal perspective. Epidemiological parameter values were derived from data of real-world or generated by model calibration; costs and effectiveness parameter values were informed either by local data or published literature. The primary outcomes were total social cost, disability adjusted life-years (DALYs) and net monetary benefit (NMB). Deterministic sensitivity analyses (DSA) and scenario analyses were performed to assess the model robustness.

RESULTS

The first wave of Omicron in Shanghai resulted in 47,646 DALYs lost and 415 billion RMB losses. At a willingness-to-pay threshold of 173,630 RMB (the GDP per capita of Shanghai in 2021) per DALY saved, the Real-world strategy was considered as the most cost-effective strategy due to its highest NMB (-407 billion). Results from DSA confirmed the robustness of our findings.

CONCLUSION

Our finding supported the Real-world strategy taken by the Shanghai Municipal Government between March 1 and May 21, 2022 to control the first wave of Omicron outbreak. Moreover, our results indicated that whether the Stricter dynamic zero-COVID strategy is worth implementing at the beginning of the COVID-19 outbreak mainly depended on the infection rate of COVID-19 among primary contacts. Our analysis provides important evidence to inform policy makers to make appropriate decisions regarding COVID-19 pandemic management.

Predicting model of mild and severe types of COVID-19 patients using Thymus CT radiomics model: A preliminary study

OBJECTIVE

To predict COVID-19 severity by building a prediction model based on the clinical manifestations and radiomic features of the thymus in COVID-19 patients.

METHOD

We retrospectively analyzed the clinical and radiological data from 217 confirmed cases of COVID-19 admitted to Xiangyang NO.1 People's Hospital and Jiangsu Hospital of Chinese Medicine from December 2019 to April 2022 (including 118 mild cases and 99 severe cases). The data were split into the training and test sets at a 7:3 ratio. The cases in the training set were compared in terms of clinical data and radiomic parameters of the lasso regression model. Several models for severity prediction were established based on the clinical and radiomic features of the COVID-19 patients. The DeLong test and decision curve analysis (DCA) were used to compare the performances of several models. Finally, the prediction results were verified on the test set.

RESULT

For the training set, the univariate analysis showed that BMI, diarrhea, thymic steatosis, anorexia, headache, findings on the chest CT scan, platelets, LDH, AST and radiomic features of the thymus were significantly different between the two groups of patients (P < 0.05). The combination model based on the clinical and radiomic features of COVID-19 patients had the highest predictive value for COVID-19 severity [AUC: 0.967 (OR 0.0115, 95%CI: 0.925-0.989)] vs. the clinical feature-based model [AUC: 0.772 (OR 0.0387, 95%CI: 0.697-0.836), P < 0.05], laboratory-based model [AUC: 0.687 (OR 0.0423, 95%CI: 0.608-0.760), P < 0.05] and model based on CT radiomics [AUC: 0.895 (OR 0.0261, 95%CI: 0.835-0.938), P < 0.05]. DCA also confirmed the high clinical net benefits of the combination model. The nomogram drawn based on the combination model could help differentiate between the mild and severe cases of COVID-19 at an early stage. The predictions from different models were verified on the test set.

CONCLUSION

Severe cases of COVID-19 had a higher level of thymic involution. The thymic differentiation in radiomic features was related to disease progression. The combination model based on the radiomic features of the thymus could better promote early clinical intervention of COVID-19 and increase the cure rate.

Impact of COVID-19 on children

Background

The COVID-19 global pandemic has spread throughout the world, posing an extremely dangerous health risk for almost everyone. While dealing with such a large-scale viral disease, the healthcare infrastructure is under strain. Young adults who were thought to have been clinically affected fared better than their older counterparts. This pandemic has affected millions of children, especially those from low-economic backgrounds, who are otherwise highly susceptible and underprivileged. Children of frontline workers and single parents face particular challenges. Children from disadvantaged backgrounds are more vulnerable to infection and may experience long-lasting negative effects of the pandemic, such as child labor, child trafficking, child marriage, sexual exploitation, and even death. To lessen the psychological negative effects of COVID-19 on children and adolescents, parents, physicians, psychologists, social workers, and hospital administrators, government and non-governmental organizations have essential responsibilities to play. Priority one is to ensure that all children from all socioeconomic strata have access to the necessities of life, including social security, health care, and education. Moreover, some positive changes may result from the global crisis. This research paper discusses the potential consequences of this pandemic. 

Summary

Some of the hypotheses being investigated while looking at the low case fatality rate among pediatric age groups include the peak of immunity and differences in immune system response. The vulnerability of the comorbid pediatric age group, on the other hand, is comparable to that of their older counterparts. During the severe acute respiratory syndrome and Middle Eastern respiratory syndrome outbreaks, similar results were observed. The inoculation of a mother during pregnancy was found to be effective in protecting her progeny.

Results

This is a review article, thus not applicable.

Conclusions

Children are quite discouraged when school is abruptly stopped, when planned outings are canceled, when they are confined to the house, and when they are afraid of the unknown with regard to the continuing epidemic. Even though almost all studies suggest that COVID-19 has a relatively mild clinical manifestation in children, one must be cautious due to the novel coronavirus’s rapid mutation rate. More research is needed to determine the relationship between COVID-19 and pediatric age groups.

Identification of Suitable Drug Combinations for Treating COVID-19 Using a Novel Machine Learning Approach: The RAIN Method

Simple Summary

This study follows an improved approach to systematic reviews, called the Systematic Review and Artificial Intelligence Network Meta-Analysis (RAIN), registered within PROSPERO (CRD42021256797), in which, the PRISMA criterion is still considered. Drugs used in the treatment of COVID-19 were searched in the databases of ScienceDirect, Web of Science (WoS), ProQuest, Embase, Medline (PubMed), and Scopus. In addition, using artificial intelligence and the measurement of the p-value between human genes affected by COVID-19 and drugs that have been suggested by clinical experts, and reported within the identified research papers, suitable drug combinations are proposed for the treatment of COVID-19. During the systematic review process, 39 studies were selected. Our analysis shows that most of the reported drugs, such as azithromycin and hydroxyl-chloroquine on their own, do not have much of an effect on the recovery of COVID-19 patients. Based on the result of the new artificial intelligence, on the other hand, at a significance level of less than 0.05, the combination of the two drugs therapeutic corticosteroid + camostat with a significance level of 0.02, remdesivir + azithromycin with a significance level of 0.03, and interleukin 1 receptor antagonist protein + camostat with a significance level 0.02 are considered far more effective for the treatment of COVID-19 and are therefore recommended.

Abstract

COVID-19 affects several human genes, each with its own p-value. The combination of drugs associated with these genes with small p-values may lead to an estimation of the combined p-value between COVID-19 and some drug combinations, thereby increasing the effectiveness of these combinations in defeating the disease. Based on human genes, we introduced a new machine learning method that offers an effective drug combination with low combined p-values between them and COVID-19. This study follows an improved approach to systematic reviews, called the Systematic Review and Artificial Intelligence Network Meta-Analysis (RAIN), registered within PROSPERO (CRD42021256797), in which, the PRISMA criterion is still considered. Drugs used in the treatment of COVID-19 were searched in the databases of ScienceDirect, Web of Science (WoS), ProQuest, Embase, Medline (PubMed), and Scopus. In addition, using artificial intelligence and the measurement of the p-value between human genes affected by COVID-19 and drugs that have been suggested by clinical experts, and reported within the identified research papers, suitable drug combinations are proposed for the treatment of COVID-19. During the systematic review process, 39 studies were selected. Our analysis shows that most of the reported drugs, such as azithromycin and hydroxyl-chloroquine on their own, do not have much of an effect on the recovery of COVID-19 patients. Based on the result of the new artificial intelligence, on the other hand, at a significance level of less than 0.05, the combination of the two drugs therapeutic corticosteroid + camostat with a significance level of 0.02, remdesivir + azithromycin with a significance level of 0.03, and interleukin 1 receptor antagonist protein + camostat with a significance level 0.02 are considered far more effective for the treatment of COVID-19 and are therefore recommended. Additionally, at a significance level of less than 0.01, the combination of interleukin 1 receptor antagonist protein + camostat + azithromycin + tocilizumab + oseltamivir with a significance level of 0.006, and the combination of interleukin 1 receptor antagonist protein + camostat + chloroquine + favipiravir + tocilizumab7 with corticosteroid + camostat + oseltamivir + remdesivir + tocilizumab at a significant level of 0.009 are effective in the treatment of patients with COVID-19 and are also recommended. The results of this study provide sets of effective drug combinations for the treatment of patients with COVID-19. In addition, the new artificial intelligence used in the RAIN method could provide a forward-looking approach to clinical trial studies, which could also be used effectively in the treatment of diseases such as cancer.

Role of thymus in health and disease

The thymus is a primary lymphoid organ, essential for the development of T-cells that will protect from invading pathogens, immune disorders, and cancer. The thymus decreases in size and cellularity with age referred to as thymus involution or atrophy. This involution causes decreased T-cell development and decreased naive T-cell emigration to the periphery, increased proportion of memory T cells, and a restricted, altered T-cell receptor (TCR) repertoire. The changes in composition and function of the circulating T cell pool as a result of thymic involution led to increased susceptibility to infectious diseases including the recent COVID and a higher risk for autoimmune disorders and cancers. Thymic involution consisting of both structural and functional loss of the thymus has a deleterious effect on T cell development, T cell selection, and tolerance. The mechanisms which act on the structural (cortex and medulla) matrix of the thymus, the gradual accumulation of genetic mutations, and altered gene expressions may lead to immunosenescence as a result of thymus involution. Understanding the molecular mechanisms behind thymic involution is critical for identifying diagnostic biomarkers and targets for treatment help to develop strategies to mitigate thymic involution-associated complications. This review is focused on the consequences of thymic involution in infections, immune disorders, and diseases, identifying potential checkpoints and potential approaches to sustain or restore the function of the thymus particularly in elderly and immune-compromised individuals.

An ethical analysis of the impacts of the COVID-19 pandemic on the health of children and adolescents

ABSTRACT The COVID-19 pandemic has impacted the lives of children and adolescents around the world. Hence, this study aimed to examine how the pandemic has impacted children and adolescents in Brazil through an ethical analysis. An interpretive analysis of Brazilian research on child and adolescent health during the pandemic was conducted. Recognizing this ethical dimension is pivotal to shedding more light on how responses to crisis situations, such as the current situation of the COVID-19 pandemic, can be shaped and where the priorities for action are according to all interested parties, situating the child between these parts of interest. Our analysis highlighted both direct and indirect effects surrounding the decision-making processes for children in the COVID-19 pandemic reality. These decisional processes must sustain the child’s right to participation to ascertain that the action taken is in the child’s best interests. Nevertheless, the Brazilian reality has shown a structural exclusion of children’s voices in decisions affecting them, particularly concerning the effects of the pandemic on their lives. Further studies must be conducted to deepen the knowledge about children’s best interests and their participation in the actions planned during the pandemic.

Análise ética dos impactos da pandemia de COVID-19 na saúde de crianças e adolescentes

RESUMO A pandemia de COVID-19 trouxe impactos significativos para a vida de crianças e adolescentes em todo o mundo. Considerando esse contexto, o objetivo deste artigo foi examinar como as crianças e os adolescentes no Brasil foram impactados pela pandemia à luz de uma análise ética. Para tanto, uma análise interpretativa de estudos brasileiros sobre a saúde da criança e do adolescente durante a pandemia foi realizada. A tarefa de reconhecer essa dimensão ética é importante para entender como as respostas a situações de crise, tais como a presente situação da pandemia de COVID-19, podem ser moldadas e identificar quais as prioridades de ação de acordo com todas as partes interessadas, situando a criança entre essas partes de interesse. A análise demonstrou que tanto os efeitos diretos quanto os indiretos implicam em processos de tomada de decisão que precisam utilizar e sustentar o direito de participação da criança para que a ação tomada esteja o máximo possível focada nos melhores interesses da criança. Contudo, a realidade brasileira tem demonstrado uma exclusão estrutural das vozes infantis. Recomenda-se que mais estudos sejam conduzidos a fim de aprofundar o conhecimento sobre os melhores interesses das crianças e sua participação nas ações tomadas durante a pandemia.

TAT-peptide conjugated repurposing drug against SARS-CoV-2 main protease (3CLpro): Potential therapeutic intervention to combat COVID-19

The Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that originated in Chinese city of Wuhan has caused around 906,092 deaths and 28,040,853 confirmed cases worldwide (https://covid19.who.int/, 11 September 2020). In a life-threatening situation, where there is no specific and licensed anti-COVID-19 vaccine or medicine available; the repurposed drug might act as a silver bullet. Currently, more than 211 vaccines, 80 antibodies, 31 antiviral drugs, 35 cell-based, 6 RNA-based and 131 other drugs are in clinical trials. It is therefore utter need of the hour to develop an effective drug that can be used for the treatment of COVID-19 before a vaccine can be developed. One of the best-characterized and attractive drug targets among coronaviruses is the main protease (3CL^pro). Therefore, the current study focuses on the molecular docking analysis of TAT-peptide^47–57 (GRKKRRQRRRP)-conjugated repurposed drugs (i.e., lopinavir, ritonavir, favipiravir, and hydroxychloroquine) with SARS-CoV-2 main protease (3CL^pro) to discover potential efficacy of TAT-peptide (TP) - conjugated repurposing drugs against SARS-CoV-2. The molecular docking results validated that TP-conjugated ritonavir, lopinavir, favipiravir, and hydroxychloroquine have superior and significantly enhanced interactions with the target SARS-CoV-2 main protease. In-silico approach employed in this study suggests that the combination of the drug with TP is an excelling alternative to develop a novel drug for the treatment of SARS-CoV-2 infected patients. The development of TP based delivery of repurposing drugs might be an excellent approach to enhance the efficacy of the existing drugs for the treatment of COVID-19. The predictions from the results obtained provide invaluable information that can be utilized for the choice of candidate drugs for in vitro, in vivo and clinical trials. The outcome from this work prove crucial for exploring and developing novel cost-effective and biocompatible TP conjugated anti-SARS-CoV-2 therapeutic agents in immediate future.

Relationship between Pneumonia and the Thymus Gland in Children with COVID-19: A Volumetric Computed Tomography Study

Objective Many studies showed that less-severe disease symptoms and fewer mortality rates have been reported in pediatric novel coronavirus disease 2019 (COVID-19) patients. In this study, we aimed to reveal the relationship between the volume of thymus gland, which provides T lymphocyte maturation in children, with the severity of lung involvement and blood laboratory values in pediatric patients with COVID-19 infection.

Methods Thymus density and thymus and cardiac volumes were measured in pediatric COVID-19 patients and a control group that underwent thoracic tomography for reasons other than infection. Thymus/heart ratios were calculated to index the thymus volumes of the patients to their body dimensions. The severity of pneumonia was demonstrated by proportioning the involved lung parenchymal volume to the total lung volume in patients with typical involvement in thoracic tomography. The relationship between volumetric and blood laboratory values was statistically evaluated.

Results Thymus density (p = 0.015) and thymus/heart ratio (p = 0.04) significantly differed between patients with COVID-19 infection and the control group. A correlation was observed between the pneumonia involvement rate and C-reactive protein (CRP) (k: 0.451, p = 0.08) and white blood cell (WBC; k: 0.419, p = 0.015) values in the thoracic tomography of the COVID-19 group.

Conclusion The thymus gland is enlarged as an indicator of activation in COVID-19 infection. We hope that our study will guide new studies on the prognostic value of thymus size in lymphopenic patients with severe disease.

COVID-19 pandemic: CT chest in COVID-19 infection and prediction of patient’s ICU needs

Background

With the tremendous rise in COVID-19 infection and the shortage of real-time reverse transcription-polymerase chain reaction (RT-PCR) testing, we aimed to assess the role of CT in the detection of COVID-19 infection and the correlation with the patients’ management. A retrospective study was conducted on 600 patients who presented with symptoms suspicious for COVID-19 infection between March and the end of June 2020. The current study followed the RSNA recommendations in CT reporting and correlated with the RT-PCR. CT was reviewed and the severity score was correlated with the patient’s management.

Results

Four hundred sixty-six patients were included with a mean age of 46 + 14.8 years and 63.3 % were males. Three hundred forty patients were confirmed positive by RT-PCR. CT sensitivity was 92.6% while the RT-PCR was the reference. The CT specificity showed a gradual increase with the CT probability reaching 97.6% with high probability CT features. Ground-glass opacities (GGO) was the commonest findings 85.9% with a high incidence of bilateral, peripheral, and multilobar involvement (88%, 92.8%, and 92.8% respectively). Consolidation was found in 81.5% of the ICU patients and was the dominant feature in 66.7% of the ICU cases. CT severity score was significantly higher in ICU patients with a score of ≥ 14.

Conclusions

COVID-19 infection showed typical CT features which can be used as a rapid and sensitive investigation. Two CT phenotypes identified with the predominant consolidation phenotype as well as severity score can be used to determine infection severity and ICU need.

Thymus Gland: A Double Edge Sword for Coronaviruses

The thymus is the main lymphoid organ that regulates the immune and endocrine systems by controlling thymic cell proliferation and differentiation. The gland is a primary lymphoid organ responsible for generating mature T cells into CD4+ or CD8+ single-positive (SP) T cells, contributing to cellular immunity. Regarding humoral immunity, the thymic plasma cells almost exclusively secrete IgG1 and IgG3, the two main complement-fixing effector IgG subclasses. Deformity in the thymus can lead to inflammatory diseases. Hassall’s corpuscles’ epithelial lining produces thymic stromal lymphopoietin, which induces differentiation of CDs thymocytes into regulatory T cells within the thymus medulla. Thymic B lymphocytes produce immunoglobulins and immunoregulating hormones, including thymosin. Modulation in T cell and naive T cells decrement due to thymus deformity induce alteration in the secretion of various inflammatory factors, resulting in multiple diseases. Influenza virus activates thymic CD4+ CD8+ thymocytes and a large amount of IFNγ. IFNs limit virus spread, enhance macrophages’ phagocytosis, and promote the natural killer cell restriction activity against infected cells. Th2 lymphocytes-produced cytokine IL-4 can bind to antiviral INFγ, decreasing the cell susceptibility and downregulating viral receptors. COVID-19 epitopes (S, M, and N proteins) with ≥90% identity to the SARS-CoV sequence have been predicted. These epitopes trigger immunity for antibodies production. Boosting the immune system by improving thymus function can be a therapeutic strategy for preventing virus-related diseases. This review aims to summarize the endocrine-immunoregulatory functions of the thymus and the underlying mechanisms in the prevention of COVID-19.

Immunity, Sex Hormones, and Environmental Factors as Determinants of COVID-19 Disparity in Women

The current coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome virus 2 (SARS-CoV-2), has resulted in a major global pandemic, causing extreme morbidity and mortality. Few studies appear to suggest a significant impact of gender in morbidity and mortality, where men are reported at a higher risk than women. The infectivity, transmissibility, and varying degree of disease manifestation (mild, modest, and severe) in population studies reinforce the importance of a number of genetic and epigenetic factors, in the context of immune response and gender. The present review dwells on several contributing factors such as a stronger innate immune response, estrogen, angiotensin-converting enzyme 2 gene, and microbiota, which impart greater resistance to the SARS-CoV-2 infection and disease progression in women. In addition, the underlying importance of associated microbiota and certain environmental factors in gender-based disparity pertaining to the mortality and morbidity due to COVID-19 in women has also been addressed.

Therapeutic development by repurposing drugs targeting SARS-CoV-2 spike protein interactions by simulation studies

The human-to-human transmitted respiratory illness in COVID-19 affected by the pathogenic Severe Acute Respiratory Syndrome Corona Virus 2 (SARS-CoV-2), which appeared in the last of December 2019 in Wuhan, China, and rapidly spread in many countries. Thereon, based on the urgent need for therapeutic molecules, we conducted in silico based docking and simulation molecular interaction studies on repurposing drugs, targeting SARS-CoV-2 spike protein. Further, the best binding energy of doxorubicin interacting with virus spike protein (PDB: 6VYB) was observed to be -6.38 kcal/mol and it was followed by exemestane and gatifloxacin. The molecular simulation dynamics analysis of doxorubicin, Reference Mean Square Deviation (RMSD), Root Mean Square fluctuation (RMSF), Radius of Gyration (Rg), and formation of hydrogen bonds plot interpretation suggested, a significant deviation and fluctuation of Doxorubicin-Spike RBD complex during the whole simulation period. The Rg analysis has stated that the Doxorubicin-Spike RBD complex was stable during 15,000-35,000 ps MDS. The results have suggested that doxorubicin could inhibit the virus spike protein and prevent the access of the SARS-CoV-2 to the host cell. Thus, in-vitro/in-vivo research on these drugs could be advantageous to evaluate significant molecules that control the COVID-19 disease.

Nano-therapeutic strategies to target coronavirus

The coronaviruses have caused severe acute respiratory syndrome (SARS), the Middle East respiratory syndrome (MERS), and the more recent coronavirus pneumonia (COVID-19). The global COVID-19 pandemic requires urgent action to develop anti-virals, new therapeutics, and vaccines. In this review, we discuss potential therapeutics including human recombinant ACE2 soluble, inflammatory cytokine inhibitors, and direct anti-viral agents such as remdesivir and favipiravir, to limit their fatality. We also discuss the structure of the SARS-CoV-2, which is crucial to the timely development of therapeutics, and previous attempts to generate vaccines against SARS-CoV and MERS-CoV. Finally, we provide an overview of the role of nanotechnology in the development of therapeutics as well as in the diagnosis of the infection. This information is key for computational modeling and nanomedicine-based new therapeutics by counteracting the variable proteins in the virus. Further, we also try to effectively share the latest information about many different aspects of COVID-19 vaccine developments and possible management to further scientific endeavors.

Diffuse functional brain disconnection syndrome in critically ill patients with COVID-19

The novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is most closely related to severe respiratory syndrome; however, recent reports showed that it is capable of causing neurological disease. Here we report a case-series of 4 critically ill COVID-19 patients who recovered from pneumonia but showed serious neurological symptoms and eventually died.

Infection-Associated Thymic Atrophy

The thymus is a vital organ of the immune system that plays an essential role in thymocyte development and maturation. Thymic atrophy occurs with age (physiological thymic atrophy) or as a result of viral, bacterial, parasitic or fungal infection (pathological thymic atrophy). Thymic atrophy directly results in loss of thymocytes and/or destruction of the thymic architecture, and indirectly leads to a decrease in naïve T cells and limited T cell receptor diversity. Thus, it is important to recognize the causes and mechanisms that induce thymic atrophy. In this review, we highlight current progress in infection-associated pathogenic thymic atrophy and discuss its possible mechanisms. In addition, we discuss whether extracellular vesicles/exosomes could be potential carriers of pathogenic substances to the thymus, and potential drugs for the treatment of thymic atrophy. Having acknowledged that most current research is limited to serological aspects, we look forward to the possibility of extending future work regarding the impact of neural modulation on thymic atrophy.

Thymic Aging May Be Associated with COVID-19 Pathophysiology in the Elderly

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) caused the global pandemic of coronavirus disease 2019 (COVID-19) and particularly exhibits severe symptoms and mortality in elderly individuals. Mounting evidence shows that the characteristics of the age-related clinical severity of COVID-19 are attributed to insufficient antiviral immune function and excessive self-damaging immune reaction, involving T cell immunity and associated with pre-existing basal inflammation in the elderly. Age-related changes to T cell immunosenescence is characterized by not only restricted T cell receptor (TCR) repertoire diversity, accumulation of exhausted and/or senescent memory T cells, but also by increased self-reactive T cell- and innate immune cell-induced chronic inflammation, and accumulated and functionally enhanced polyclonal regulatory T (Treg) cells. Many of these changes can be traced back to age-related thymic involution/degeneration. How these changes contribute to differences in COVID-19 disease severity between young and aged patients is an urgent area of investigation. Therefore, we attempt to connect various clues in this field by reviewing and discussing recent research on the role of the thymus and T cells in COVID-19 immunity during aging (a synergistic effect of diminished responses to pathogens and enhanced responses to self) impacting age-related clinical severity of COVID-19. We also address potential combinational strategies to rejuvenate multiple aging-impacted immune system checkpoints by revival of aged thymic function, boosting peripheral T cell responses, and alleviating chronic, basal inflammation to improve the efficiency of anti-SARS-CoV-2 immunity and vaccination in the elderly.

Wide spectrum of clinical picture of COVID-19 in children - From mild to severe disease

INTRODUCTION

Children account for a relatively small proportion of laboratory-confirmed SARS-CoV-2 infections. In children, COVID-19 usually has a relatively mild course. However, in rare cases, severe disorders can be observed, and clinical manifestations may differ from adults.

PURPOSE

The aim of this study is to analyse the frequency, clinical picture and outcome of COVID-19 in children based on the experience from the tertiary care centre and regional sanitary-epidemiological office.

METHODS

We report a study regarding 106 cases of confirmed SARS-CoV-2 infection cases in PCR from a nasopharyngeal swab (age range 1-month - 17-years). In all cases, history was taken. In children who required hospital admission, physical examination and laboratory test were performed according to clinical indications.

RESULTS

Twelve of the patients required admission to the hospital. The most common symptoms were anosmia and dysgeusia (75%) and headaches (49%) in outpatients and fever in hospitalised children (75%). Three children from the hospitalised group developed a severe course with increased inflammatory indexes. The clinical picture was more severe in younger children from the hospitalised group. Treatment options were regarded individually in all cases.

CONCLUSION

Our study is the first tour knowledge regarding the clinical course of COVID-19 in Polish children. In general, the clinical course of COVID-19 was mild with anosmia and dysgeusia as the most common symptoms. However, in hospitalised children, a severe progression of the disease and less typical signs as aplastic anaemia may be developed.

Atypical Manifestations of Severe Acute Respiratory Syndrome Coronavirus 2 Infection in Children: A Systematic Review

BACKGROUND

In December 2019, a local outbreak of pneumonia was presented in Wuhan (China) and quickly identified to be caused by a novel coronavirus, Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). The disease caused by SARS-CoV-2 was named COVID-19 and was soon declared a pandemic because of the millions of infections and thousands of deaths worldwide. Children infected with SARS-CoV-2 usually develop the asymptomatic or mild type of disease compared to adults. They are also more likely to have atypical and non-specific clinical manifestations than adults.

METHODS

A literature search was performed through PubMed and Scopus to summarize the extrapulmonary manifestations of SARS-CoV-2 infection in children since the beginning of the pandemic. Peer-reviewed papers in English were retrieved using the following keywords and combinations: 'pediatric,' 'child,' 'infant,' 'neonate,' 'novel coronavirus,' 'SARS-CoV-2,' 'COVID 19' and 'gastrointestinal,' 'renal,' 'cardiac,' 'dermatologic' or 'ophthalmologic'. We included published case series and case reports providing clinical symptoms and signs in SARS-CoV2 pediatric patients.

RESULTS

Although fever and symptoms of upper respiratory infection are the most frequently presented, a variety of other atypical presentations has also been reported. The clinical spectrum includes dermatological, ophthalmological, neurological, cardiovascular, renal, reproductive, and gastrointestinal presentations. In addition, a rare multi-inflammatory syndrome associated with SARS-- CoV-2 infection has been reported in children, often leading to shock and requiring inotropic support and mechanical ventilation.

CONCLUSION

Clinicians need to be aware of the wider range of extrapulmonary atypical manifestations of SARS-CoV-2 infection in children, so that appropriate testing, treatment, and public health measures can be implemented rapidly.

Aging in COVID-19: Vulnerability, immunity and intervention

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) pandemic was first reported in Wuhan, China in December 2019, moved across the globe at an unprecedented speed, and is having a profound and yet still unfolding health and socioeconomic impacts. SARS-CoV-2, a β-coronavirus, is a highly contagious respiratory pathogen that causes a disease that has been termed the 2019 coronavirus disease (COVID-19). Clinical experience thus far indicates that COVID-19 is highly heterogeneous, ranging from being asymptomatic and mild to severe and causing death. Host factors including age, sex, and comorbid conditions are key determinants of disease severity and progression. Aging itself is a prominent risk factor for severe disease and death from COVID-19. We hypothesize that age-related decline and dysregulation of immune function, i.e., immunosenescence and inflammaging play a major role in contributing to heightened vulnerability to severe COVID-19 outcomes in older adults. Much remains to be learned about the immune responses to SARS-CoV-2 infection. We need to begin partitioning all immunological outcome data by age to better understand disease heterogeneity and aging. Such knowledge is critical not only for understanding of COVID-19 pathogenesis but also for COVID-19 vaccine development.

A case series report of hospitalized children with severe acute respiratory syndrome coronavirus-2 infection in Jinan, China

In December 2019, the outbreak of novel severe acute respiratory syndrome coronavirus-2 infection was reported in Wuhan, China. The disease has spread rapidly throughout China and the rest of the world. It not only occurred in adults but also in some children. So, in this report, we aimed to clarify the epidemiological, clinical, laboratory, and radiological characteristics; treatment; and outcomes of children infected with severe acute respiratory syndrome coronavirus-2 in Jinan, China, and found that children with severe acute respiratory syndrome coronavirus-2 infection are non-specific and are milder than adults. Asymptomatic infections were common. Chest computed tomographic scanning is helpful for diagnosis. While myocardial creatine kinase–myocardial band was prone to increase in these cases. The prognosis of most cases was better.

COVID-19 infection prevalence in pediatric population: Etiology, clinical presentation, and outcome

Novel COVID-19 infections caused major morbidity and mortality globally in the adult age group. Likewise, SARS-COV-2 infections in children are highly risky in the selected patient population. We performed a focused literature search of published reports from December 1, 2019, till August 20, 2020. The aim was to explore the etiology, clinical presentations, and outcome of pediatric COVID-19 patients. Viral respiratory infections are associated with high societal costs for children. In addition, children with asymptomatic SARS-COV-2 infections can be a source of COVID-19 spread to parents and caregivers. The major reported risk factors for pediatric COVID-19 cases were close contact with a SARS-COV-2 positive family member, a history of travel, and/or living in endemic areas. Children with COVID-19 who required ICU care had various comorbidities, such as malignancy. As the pandemic evolved, multiple cases of multisystem inflammatory syndrome in children and adolescents temporarily related to covid-19 (MIS-C) were reported. A unique population is neonates born to COVID-19 affected mothers, as there is an urgent need to optimize their management and outcome during this rapidly evolving pandemic. The early identification of SARS-COV-2 infection in infants and children has important direct management effects in these children and public health implications because of the effects on disease transmission control measures.

Syndrome resembling Kawasaki disease in COVID-19 asymptomatic children

The current knowledge about the COVID-19 (Coronavirus Disease-2019) pandemic is still limited and is unravelling with the passing days, especially clinical data, and research in pediatric age group. Recently, there is a new and crucial development reported recently among the COVID-19 asymptomatic children, a novel syndrome affecting asymptomatic COVID-19 children, presenting as a hyperinflammatory syndrome which is like Kawasaki disease shock syndrome. The purpose of this correspondence is to discuss some important findings of the syndrome for the better understanding of the disease.

From SARS to COVID-19: What lessons have we learned?

After the outbreak of severe acute respiratory syndrome (SARS) in November 2002, coronaviruses (CoVs) received worldwide attention. On December 1, 2019, the first case of coronavirus disease 2019 (COVID-19), caused by a novel coronavirus (SARS-CoV-2), was reported in Wuhan, China, and CoVs returned to public view. On January 30, 2020, the World Health Organization (WHO) declared that the COVID-19 epidemic is a public health emergency of international concern (PHEIC), and on March 11, 2020, the WHO classified COVID-19 as a pandemic disease. As of July 31, 2020, COVID-19 has affected 216 countries and regions, with 17,064,064 confirmed cases and 668,073 deaths, and the number of new cases has been increasing daily. Additionally, on March 19, 2020, there were no new confirmed cases in China, providing hope and valuable experience for the international community. In this review, we systematically compare COVID-19 and SARS in terms of epidemiology, pathogenesis and clinical characteristics and discuss the current treatment approaches, scientific advancements and Chinese experience in fighting the epidemic to combat the novel coronavirus pandemic. We also discuss the lessons that we have learned from COVID-19 and SARS.

Angiotensin-converting enzyme 2: A protective factor in regulating disease virulence of SARS-COV-2

Novel SARS-CoV-2 named due to its close homology with severe acute respiratory syndrome coronavirus (SARS-CoV) is the etiologic agent for the ongoing pandemic outbreak causing loss of life and severe economic burden globally. The virus is believed to be evolved in a recombined form of bat and animal coronavirus with the capacity to infect human host using the ACE2 receptors as an entry point. Though the disease pathogenesis is not elucidated completely, the virus-mediated host response retains a similar pattern to that of previous SARS-CoV. Based on the available trend it is assumed that pediatric groups are less susceptible to the coronavirus. Understanding the possible mechanism that protects the children from hyper-inflammatory or disease severity could lead to better treatment modalities. In the present review, we have discussed the significance of age and sex-dependent pattern of ACE2 receptor expression and ACE2 variants in the immune protective mechanism of the disease virulence. We have also added a brief note on the importance of sex hormones in the pathogenesis of ACE2 mediated SARS-CoV2 infection.

Salient Conclusive Remarks on Epidemiology and Clinical Manifestations of Pediatric COVID-19: Narrative Review

The ongoing pandemic of COVID-19, which is caused by the novel coronavirus named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), constituted significant public health concerns and impacted the human populations with massive economic and social burdens worldwide. The disease is known to infect people of all ages, including children, adults, and the elderly. Although several reports about pediatric COVID-19 were seen in the literature, we believe that the epidemiology and pathology of the infection described in these reports are not conclusive. Therefore, in this scientific communication, a narrative review study was performed to shed some light on the characteristic epidemiological features and clinical phenotypes of pediatric COVID-19. In this report, we had compiled and presented the different epidemiological features of the disease related to the age of infection, virus acquisition, explanations of the low infectivity rates, and consequences of infections. The discriminatory clinical manifestations of the disease in children were also addressed and discussed in this review. The search included the data published from the date of the start of the pandemic in December 2019 up to October 2020. Our literature search revealed that children of all ages, including neonates, had been infected by the virus. Despite the fact that pediatric COVID-19 is less common to occur, as compared to the disease in adults, the infected children usually manifest the disease symptomatology in benign form. Asymptomatic and symptomatic adult patients are the primary source of the virus to the children. Intrauterine transmission of the virus and breastfeeding infections to the neonates were hypothesized in some studies but ruled out since they were not confirmed. Intensive review and discussion warranting the low infection rates and benign conditions of COVID-19 in children were also made in this study. As documented in many studies, the infectivity, morbidity, and mortality rates of the disease among the children populations are much lower than those in adults. They also seem to be lower than those observed during SARS-CoV and MERS-CoV epidemics. The described clinical phenotypes of COVID-19 in children do not differ much from those of adults, and complications of the disease seem to be associated with comorbidities.