COVID-19 in children: Pathogenesis and current status

Clinical characteristics and outcomes of COVID-19 in pediatric patients with rheumatic diseases

BACKGROUND

This study investigates the clinical characteristics and outcomes of pediatric patients with rheumatic diseases infected with COVID-19 in China.

METHODS

We conducted a retrospective analysis of pediatric patients with rheumatic diseases who contracted COVID-19. Data were collected via a comprehensive questionnaire with a 14-day follow-up. Multivariable logistic regression was used to assess severe outcomes, and network analyses evaluated symptom correlations.

RESULTS

A total of 1070 cases were collected. Fever (88.05%) and cough (62.75%) were the most common symptoms. Cough, nasal congestion, and runny nose exhibited a stronger correlation with each other. A higher incidence of fever reduced the incidence of two single symptoms (nasal congestion [r = -0.833], runny nose [r = -0.762]). Vaccinated children showed a shorter time to negative COVID-19 conversion (7.21 days vs. 7.63 days, p < 0.05) and lower hospitalization rates (p = 0.025). Prolonged symptom duration was associated with older age (OR: 1.07 [1.04-1.11]; p < 0.001) and systemic lupus erythematosus (OR: 1.47 [1.01-2.12]; p = 0.046).

CONCLUSIONS

Pediatric patients with rheumatic diseases exhibited a wide range of clinical symptoms after COVID-19 infection. The infection generally did not lead to severe outcomes in this study. COVID-19 vaccination was associated with reduced hospitalization risk and expediting the time to negativity for virus.

IMPACTS

This manuscript demonstrates a comprehensive analysis of the clinical characteristics and outcomes of COVID-19 infection in pediatric patients with rheumatic diseases in China. It provides critical insights into the specific challenges faced by this vulnerable population and offers practical recommendations for improving patient management during periods of increased infectious risk.

SARS-CoV-2 Variants of Concern and Clinical Severity in the Mexican Pediatric Population

The emergence of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) variants of concern (VOCs) presents global heterogeneity, and their relative effect on pediatric severity is still limited. In this study, we associate VOCs with pediatric clinical severity outcomes in Mexico. Bioinformatics methods were used to characterize VOCs and single amino acid (aa) mutations in 75,348 SARS-CoV-2 genetic sequences from February 2020 to October 2022. High-predominance VOCs groups were calculated and subsequently associated with 372,989 COVID-19 clinical pediatric outcomes. We identified 21 high-frequency mutations related to Omicron lineages with an increased prevalence in pediatric sequences compared to adults. Alpha and the other lineages had a significant increase in case fatality rate (CFR), intensive critical unit (ICU) admission, and automated mechanical ventilation (AMV). Furthermore, a logistic model with age-adjusted variables estimated an increased risk of hospitalization, ICU/AMV, and death in Gamma and Alpha, in contrast to the other lineages. We found that, regardless of the VOCs lineage, infant patients presented the worst severity prognoses. Our findings improve the understanding of the impact of VOCs on pediatric patients across time, regions, and clinical outcomes. Enhanced understanding of the pediatric severity for VOCs would enable the development and improvement of public health strategies worldwide.

Circulating sTREM-1 as a predictive biomarker of pediatric multisystemic inflammatory syndrome (MIS-C)

The exacerbation of the inflammatory response caused by SARS-CoV-2 in adults promotes the production of soluble mediators that could act as diagnostic and prognostic biomarkers for COVID-19. Among the potential biomarkers, the soluble triggering receptor expressed on myeloid cell-1 (sTREM-1) has been described as a predictor of inflammation severity. The aim was to evaluate sTREM-1 and cytokine serum concentrations in pediatric patients during the acute and convalescent phases of COVID-19. This was a prospective study that included 53 children/adolescents with acute COVID-19 (Acute-CoV group); 54 who recovered from COVID-19 (Post-CoV group) and 54 controls (Control group). Preexisting chronic conditions were present in the three groups, which were defined as follows: immunological diseases, neurological disorders, and renal and hepatic failures. The three groups were matched by age, sex, and similar preexisting chronic conditions. No differences in sTREM-1 levels were detected among the groups or when the groups were separately analyzed by preexisting chronic conditions. However, sTREM-1 analysis in the seven multisystemic inflammatory syndrome children (MIS-C) within the Acute-Cov group showed that sTREM-1 concentrations were higher in MIS-C vs non-MIS-C acute patients. Then, the receiver operating curve analysis (ROC) performed with MIS-C acute patients revealed a significant AUC of 0.870, and the sTREM-1 cutoff value of > 5781 pg/mL yielded a sensitivity of 71.4 % and a specificity of 91.3 % for disease severity, and patients with sTREM-1 levels above this cutoff presented an elevated risk for MIS-C development in 22.85-fold (OR = 22.85 [95 % CI 1.64-317.5], p = 0.02). The cytokine analyses in the acute phase revealed that IL-6, IL-8, and IL-10 concentrations were elevated regardless of whether the patient developed MIS-C, and those levels decreased in the convalescent phase, even when compared with controls. Spearman correlation analysis generated positive indexes between sTREM-1 and IL-12 and TNF-α concentrations, only within the Acute-CoV group. Our findings revealed that sTREM-1 in pediatric patients has good predictive accuracy as an early screening tool for surveillance of MIS-C cases, even in patients with chronic underlying conditions.

Case report: Increased troponin level in 125 children during COVID-19

Introduction

Increase in cardiac biomarkers during Coronavirus disease 2019 (COVID-19) was frequent regardless of the presence of myocarditis and multisystem inflammatory syndrome in children (MIS-C). Several studies described MIS-C, but few papers evaluated cardiac manifestations in children with SARS-CoV-2 infection without MIS-C and investigated the role of troponin in absence of electrocardiogram (ECG) and echocardiographic alterations. The aim of this case series is to describe the cardiac manifestations during COVID-19 in children, trying to explain the meaning of laboratory findings during COVID-19, especially of increased troponin.

Materials and methods

We conducted a retrospective case series of children aged <18 years admitted at the Department of Pediatrics, University of Chieti, for SARS-CoV-2 infection between 1st March 2020 and 31th July 2022. All patients with documented SARS-CoV-2 infection underwent a laboratory evaluation at admission. Children with increased troponin I and/or BNP underwent electrocardiographic and echocardiographic exams.

Results

125 children were admitted for SARS-CoV-2 infection to our Department of Pediatrics, of whom 17 (13.6% of cases) with different patterns of cardiac involvement. Specifically, 5 subjects (4.0% of admitted children) were diagnosed as MIS-C and 12 children (9.6%) manifested a cardiac involvement in terms of increased troponin with or without ECG and echocardiography anomalies. Troponin, C-reactive protein, procalcitonin and BNP values resulted higher in patients with MIS-C compared to patients without MIS-C. Furthermore, patients with MIS-C had higher neutrophils and lower lymphocytes compared to patients without MIS-C. ECG abnormalities were found in 4/5 patients with MIS-C and in 2/12 patients without MIS-C. Echocardiographic anomalies were found in all patients with MIS-C, especially in terms of valve regurgitation and ejection fraction reduction and in 2/12 patients without MIS-C, especially in terms of pericardial effusion. Despite high troponin levels, children presented a favorable clinical evolution.

Conclusion

The increase in troponin level in children with COVID-19 could also be due to respiratory causes or a massive inflammatory state. In our case series, patients with increased troponin associated to COVID-19 presented a favorable clinical course with clinical and laboratory remission almost always within 7 days.

Real-World Immunogenicity and Reactogenicity of Two Doses of Pfizer-BioNTech COVID-19 Vaccination in Children Aged 5-11 Years

There are limited data concerning the immunogenicity and reactogenicity of COVID-19 vaccines in children. A total of 110 children, 5-11 years old were vaccinated with two doses (with a 3-week interval between doses) of the Pfizer-BioNTech COVID-19 vaccine and were followed for 21, 90, and 180 days after vaccination for immunogenicity, adverse events, and breakthrough infections. Ninety days after the first vaccine dose, the GeoMean (CI 95%) of IgG ascended to 1291.0 BAU (929.6-1790.2) for uninfected children and 1670.0 BAU (1131.0-2466.0) for Infected children. One hundred and eighty days after receiving the first dose of the vaccine, the titers decreased to 535.5 BAU (288.4-993.6) for the uninfected children, while only a small decline was detected among infected children-1479.0 (878.2-2490.0). The neutralizing antibodies titer almost did not change over time in the uninfected children, and even elevated for the infected children. Of the 110 vaccinated children, 75.5% were infected, with only mild COVID-19 infection symptoms. Child vaccination was found to be safe, with mild, mostly local, and of short duration, reported AEs. No serious adverse events (SAEs) were reported after vaccination. The durability of two doses of vaccine in children is longer, thus a booster may not be needed as early as in adults.

Monkeypox viral infection and disease: A challenge for the allergist-immunologist

Background: Human monkeypox is a zoonosis caused by the monkeypox virus, an orthopoxvirus and close relative of variola virus, the causative agent of smallpox. The disease was first reported in central Africa in 1970, where it continues to be endemic and has historically affected some of the poorest and most marginalized communities in the world. The condition has recently attracted global attention due to >14,000 cases, including five deaths, reported by the World Health Organization, and a total of 5189 confirmed monkeypox cases in the United States reported by the Centers for Disease Control and Prevention as of July 29, 2022. On July 23, 2022, the World Health Organization declared the current monkeypox outbreak a Public Health Emergency of International Concern. Objective: The purpose of the present report was to review the epidemiology of monkeypox viral infection; its clinical manifestations; and current recommendations for diagnosis, treatment, and use of vaccines for prevention of the disease, with a focus on those aspects that have particular relevance to the allergist/immunologist. Results: Monkeypox was discovered in the early 1970s and, for years, has been well described by researchers in west and central Africa, where the disease has been present for decades. Although this outbreak thus far has mostly affected men who have sex with men, it is possible that the disease could become endemic and could begin spreading in settings where there is close physical contact, which is how the virus is transmitted. Conclusion: Monkeypox is a different viral infection from the coronavirus. Unlike the coronavirus, which is an extremely contagious respiratory pathogen, monkeypox is primarily transmitted through body fluids and/or prolonged skin-to-skin contact. Although the control of monkeypox will require renewed efforts and resources, we have learned much from the past and have the tools to stop this virus from becoming yet another serious illness with which Americans have to contend. The allergist/immunologist can play a significant role.

Multisystem inflammatory syndrome in children (MIS-C) showing disseminated aspergillosis, cytomegalovirus reactivation and persistent SARS-COV-2: Case report with autopsy review

Multisystem inflammatory syndrome in children (MIS-C) is an emerging phenomenon associated with SARS-COV-2 infection (COVID-19) occurring in < 1 % of infected children. MIS-C is characterized by a hyperinflammatory state with excessive cytokine release ('storm') leading to hemodynamic compromise and multiorgan failure, with a death rate of ∼2 %. Autopsy examination can play a particularly important role in helping to understand the pathogenesis of MIS-C. Yet, only five autopsy studies have been reported to date. We report a fatal case of MIS-C involving a previously healthy, 5-year-old Thai boy admitted with MIS-C, one month after exposure to SARS-COV-2. While in intensive care, he was found to have a hypertrophic cardiomyopathy, and despite immunosuppressive treatment for MIS-C, developed shock and died. Multiorgan inflammation was not found at autopsy, implying that the MIS-C had responded to treatment. However, there was disseminated aspergillosis and cytomegalovirus reactivation, attributed to the immunosuppression. SARS-COV-2 virus was also found in multiple organs. To the best of our knowledge, this is the first reported autopsy of an MIS-C patient from Asia, and the first report of aspergillosis in MIS-C. This case underscores that the risks of immunosuppression are also a concern in MIS-C. Although MIS-C is generally considered to be a post-infectious hyperimmune reaction, persistence of SARS-COV-2 is a feature in all autopsies of MIS-C patients reported to date, suggesting a possible role in the pathogenesis, at least in fatal cases.

Clinical features and severe acute respiratory syndrome-coronavirus-2 structural protein-based serology of Mexican children and adolescents with coronavirus disease 2019

Severe acute respiratory syndrome (SARS)-coronavirus (CoV)-2 infection in children and adolescents primarily causes mild or asymptomatic coronavirus disease 2019 (COVID-19), and severe illness is mainly associated with comorbidities. However, the worldwide prevalence of COVID-19 in this population is only 1%–2%. In Mexico, the prevalence of COVID-19 in children has increased to 10%. As serology-based studies are scarce, we analyzed the clinical features and serological response (SARS-CoV-2 structural proteins) of children and adolescents who visited the Hospital Infantil de México Federico Gómez (October 2020–March 2021). The majority were 9-year-old children without comorbidities who were treated as outpatients and had mild-to-moderate illness. Children aged 6–10 years and adolescents aged 11–15 years had the maximum number of symptoms, including those with obesity. Nevertheless, children with comorbidities such as immunosuppression, leukemia, and obesity exhibited the lowest antibody response, whereas those aged 1–5 years with heart disease had the highest levels of antibodies. The SARS-CoV-2 spike receptor-binding domain-localized peptides and M and E proteins had the best antibody response. In conclusion, Mexican children and adolescents with COVID-19 represent a heterogeneous population, and comorbidities play an important role in the antibody response against SARS-CoV-2 infection.

Ultrasound Comparative Analysis of Coronary Arteries before and after Immune Blocking Therapy with Gamma Globulin in Children with Kawasaki Disease

Objective

To investigate the ultrasound characteristics and clinical efficacy of coronary arteries before and after immune blocking therapy with gamma globulin in children with Kawasaki disease.

Methods

A total of 64 children with Kawasaki disease who were treated in our hospital from January 2018 to October 2021 were selected. All the children were given immune blocking therapy with gamma globulin on the basis of conventional treatment. The disappearance time of related symptoms and signs (fever, mucosal congestion, cervical lymphadenopathy, and swelling of the hands and feet) in children were counted. The white blood cell count (WBC), platelet count (PLT), C-reactive protein (CRP), and procalcitonin (PCT) levels of the children before and after treatment were compared, and the characteristics of coronary echocardiography before and after treatment were observed for analysis and discussion, to carefully observe whether the coronary artery involvement of the children was improved.

Results

The inner diameter of the left and right coronary arteries significantly decreased (P < 0.05), and the levels of leukocytes, platelets, CRP, erythrocyte sedimentation rate, vascular endothelial growth factor (VEGF), and endostatin were significantly decreased compared with those before treatment, with a statistical difference (P < 0.05).

Conclusion

The effect of gamma globulin in the treatment of Kawasaki disease is remarkable, which can improve the blood indexes, VEGF, and endostatin levels in children, significantly reduce coronary dilatation, and reduce the incidence of coronary artery disease. Echocardiography is of high value in the examination of children with Kawasaki disease, which can accurately detect the size, location, and inner diameter of coronary artery lesions, and can effectively evaluate the treatment effect on children.

Multisystem Inflammatory Syndrome in Children Associated with COVID-19 Infection: A Comprehensive Review

The Multisystem Inflammatory Syndrome in Children (MIS-C) is a postinfectious syndrome associated with coronavirus disease 2019 (COVID-19) disease in children. The aim of this study is to conduct a thorough review to assist health care professionals in diagnosis and management of this complication of COVID-19 disease in children. A thorough systematic review was conducted through an on-line search based on MIS-C with the primary focus on epidemiology, clinical characteristics, diagnosis, pathophysiology, management, and long-term follow-up. This syndrome is characterized by an exaggerated and uncontrolled release of proinflammatory cytokines involving dysfunction of both innate and adaptive immunity. In this review, a summary of observational studies and case reports was conducted, in which we found that MIS-C generates multiple-organ failure frequently presenting with hemodynamic instability further characterized by Kawasaki-like symptoms (such as persistent high fever, polymorphic rash, and bilateral conjunctivitis) and predominance of gastrointestinal and cardiovascular signs and symptoms. Keys to effective management involve early diagnosis, timely treatment and re-evaluation following hospital discharge. Diagnosis is marked by significant elevation of inflammatory biomarkers, laboratory evidence of COVID-19 infection or history of recent exposure, and absence of any other plausible explanation for the associated signs, symptoms, and presentation. Management includes hemodynamic stabilization, empiric antibiotic therapy (de-escalation if cultures and polymerase chain reaction studies indicate no bacterial co-infection), immunomodulatory therapy (methylprednisolone, intravenous immunoglobulin, anakinra, tocilizumab, siltuximab, Janus kinase inhibitors, tumor necrosis factor-α inhibitors), antivirals (remdesivir), and anticoagulation (acetylsalicylic acid, unfractionated or low-molecular-weight heparin or new oral anticoagulants). In addition, we identified poor prognostic risk factors to include concurrent comorbidities, blood-component consumption and marrow suppression (lymphopenia, thrombocytopenia), depletion of homeostatic components (hypoalbuminemia), and marked evidence of a hyperinflammatory response to include elevated values of ferritin, C-reactive protein, and D-dimer. MIS-C constitutes a postinfectious syndrome characterized by a marked cytokine storm, characterized by fever, bilateral conjunctivitis, and multiple organ dysfunction. Promoting future research and long-term follow-up will be essential for the development of guidelines and recommendations leading to effective identification and management of MIS-C.

Obesity and COVID-19 in Children and Adolescents: Reciprocal Detrimental Influence—Systematic Literature Review and Meta-Analysis

The dramatic lifestyle changes forced by COVID-19-related lockdown promoted weight gain, with a stronger impact on obese subjects, at higher risk of severe infection. The PubMed database was searched to identify original studies assessing: (1) the extent and risk factors of lockdown-induced weight increase; and (2) the impact of obesity on the risk of hospital admission in children and adolescents. A systematic literature review and meta-analyses were performed. Twenty out of 13,986 identified records were included. A significant weight increase was reported in the majority of subjects, with no apparent gender or age differences. It was induced by a higher consumption of hypercaloric/hyperglycemic/junk food and/or the reduction of physical activity, often associated with an altered sleep–wake cycle. On the other hand, obesity increased the risk of hospitalization (OR = 4.38; 95% C.I. 1.46–13.19; p = 0.009; I² = 96%) as compared to the normal weight population. COVID-19 and obesity represent epidemic conditions with reciprocal detrimental impact. Urgent public health interventions, targeting the various age and social strata, and involving governmental authorities, health care personnel, teachers and families are warranted to increase awareness and actively promote healthy lifestyles to contrast pediatric obesity and its detrimental consequences at a global level.

COVID-19 Infection in Children and Infants: Current Status on Therapies and Vaccines

Since the beginning in December 2019, the SARS-CoV-2 outbreak appeared to affect mostly the adult population, sparing the vast majority of children who only showed mild symptoms. The purpose of this investigation is to assess the status on the mechanisms that give children and infants this variation in epidemiology compared to the adult population and its impact on therapies and vaccines that are aimed towards them. A literature review, including in vitro studies, reviews, published guidelines and clinical trials was performed. Clinical trials concerned topics that allowed a descriptive synthesis to be produced. Four underlying mechanisms were found that may play a key role in providing COVID-19 protection in babies. No guidelines are available yet for therapy due to insufficient data; support therapy remains the most used. Only two vaccines are approved by the World Health Organization to be used in children from 12 years of age, and there are currently no efficacy or safety data for children below the age of 12 years. The COVID-19 clinical frame infection is milder in children and adolescents. This section of the population can act as vectors and reservoirs and play a key role in the transmission of the infection; therefore, vaccines are paramount. More evidence is required to guide safely the vaccination campaign.

Therapeutic Strategies for COVID-19 Lung Disease in Children

The novel Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection has milder presentation in children than in adults, mostly requiring only supportive therapy. The immunopathogenic course of COVID-19 can be divided in two distinct but overlapping phases: the first triggered by the virus itself and the second one by the host immune response (cytokine storm). Respiratory failure or systemic involvement as Multisystem Inflammatory Syndrome in Children (MIS-C) requiring intensive care are described only in a small portion of infected children. Less severe lung injury in children could be explained by qualitative and quantitative differences in age-related immune response. Evidence on the best therapeutic approach for COVID-19 lung disease in children is lacking. Currently, the approach is mainly conservative and based on supportive therapy. However, in hospitalized children with critical illness and worsening lung function, antiviral therapy with remdesivir and immunomodulant treatment could be considered the "therapeutic pillars."

Exhausted NK cells and cytokine storms in COVID-19: Whether NK cell therapy could be a therapeutic choice

The global outbreak of coronavirus-2019 (COVID-19) still claims more lives daily around the world due to the lack of a definitive treatment and the rapid tendency of virus to mutate, which even jeopardizes vaccination efficacy. At the forefront battle against SARS-CoV-2, an effective innate response to the infection has a pivotal role in the initial control and treatment of disease. However, SARS-CoV-2 subtly interrupts the equations of immune responses, disrupting the cytolytic antiviral effects of NK cells, while seriously activating infected macrophages and other immune cells to induce an unleashed "cytokine storm", a dangerous and uncontrollable inflammatory response causing life-threatening symptoms in patients. Notably, the NK cell exhaustion with ineffective cytolytic function against the sources of exaggerated cytokine release, acts as an Achilles' heel which exacerbates the severity of COVID-19. Given this, approaches that improve NK cell cytotoxicity may benefit treatment protocols. As a suggestion, adoptive transfer of NK or CAR-NK cells with proper cytotolytic potentials and the lowest capacity of cytokine-release (for example CD56dim NK cells brightly express activating receptors), to severe COVID-19 patients may provide an effective cure especially in cases suffering from cytokine storms. More intriguingly, the ongoing evidence for persistent clonal expansion of NK memory cells characterized by an activating phenotype in response to viral infections, can benefit the future studies on vaccine development and adoptive NK cell therapy in COVID-19. Whether vaccinated volunteers or recovered patients can also be considered as suitable candidates for cell donation could be the subject of future research.

The immunologic response to severe acute respiratory syndrome coronavirus 2

Background: The spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has precipitated the worst global pandemic in a century, which has caused millions of infections and deaths as well as massive economic repercussions. Objective: As with any pathogenic virus, it is crucial to understand its unique interactions with the human immune system so that pharmaceutical and prophylactic interventions can be deployed to effectively control the pandemic. Methods: A literature search by using PubMed was conducted in 2020 with variants of the terms "COVID-19," "SARS-CoV-2," and "immunological response." English language articles that presented original data about the immunologic response to coronavirus disease 2019 (COVID-19) were selected for review. This article reviewed the current understanding of the innate and adaptive immune responses to SARS-CoV-2 infection, including their relationship to current therapeutic and diagnostic strategies. Results: SARS-CoV-2 uses several unique molecular techniques to evade detection by the innate immune system early in the course of infection, and upregulation of these innate immune pathways may possibly accelerate the time to recovery and prevent severe disease. Although the majority of cases results in the patients' recovery, a significant proportion of infections result in deaths prompted by the host's inflammatory overreaction to the infection, a response that can be attenuated with corticosteroids and potentially other immune modulators. Conclusion: Current work by the scientific community to further understand how SARS-CoV-2 interacts with the human immune system will be invaluable to our response and preparedness for future coronavirus pandemics.

The global burden of vaccine-preventable infectious diseases in children less than 5 years of age: Implications for COVID-19 vaccination. How can we do better?

Background: Infectious diseases are a leading cause of morbidity and mortality worldwide. As of 2018, the total world population of children < 5 years of age was roughly estimated at 679 million. Of these children, an estimated 5.3 million died of all causes in 2018, with an estimated 700,000 who died of vaccine-preventable infectious diseases; 99% of the children who died had lived in low- and middle-income countries. The infectious diseases that remain major causes of mortality for which vaccines have been shown to provide proven preventive success include, in order of prevalence, are those caused by Streptococcus pneumoniae, Rotavirus, Bordetella pertussis, measles virus, Haemophilus influenzae type b and influenza virus. Objective: The purpose of the present report was to address the global burden of these six vaccine-preventable infectious diseases in children < 5 years of age, together with implications for the prevention of coronavirus disease 2019 (COVID-19) infection in children. Methods: The current immunization strategies for the prevention of the six vaccine-preventable infectious diseases in children are reviewed as a framework for new strategies of vaccine prevention of COVID-19 in children. Results: The burden of addressing vaccine prevention of future infectious disease in children can be effectively pursued through knowledge gained from past experiences with vaccine usage in these six vaccine-preventable childhood infectious diseases. Conclusion: Issues with regard to the burden of disease mortality, disease transmission, and available vaccines as well as vaccine successes and shortcomings for specific pathogens can serve as important landmarks for effective use of future vaccines. Although much success has been made globally in preventing these childhood deaths, much remains to be done.

An Overview of Asthma and COVID-19: Protective Factors Against SARS-COV-2 in Pediatric Patients

Coronavirus disease 2019 (COVID-19) is a pandemic infectious disease caused by severe acute respiratory syndrome coronavirus SARS-COV-2. Aberrant innate immunity response and cytokine storm are responsible for the syndrome. Apparently, in asthmatic patients, the inadequate antiviral immune response and the tendency for asthma exacerbation evoked by common respiratory viruses could explain increased susceptibility to SARS-COV-2 infection. However, asthma has not been suggested to be a risk factor in COVID-19 patients. Therefore, in asthmatic patients some potential protective mechanisms against SARS-COV-2 have been hypothesized, like type 2 immune response, number of eosinophils, overproduction of mucus, and asthma treatment, along with behavioral factors not strictly related to asthma, such as social distancing, hygiene measures and wearing facemasks, that contribute to reduce the individual susceptibility to SARS-COV-2 infection. In this mini-review, we will describe the current literature regarding potential protective factors against COVID-19 in children with asthma based on the evidence available so far.

Similarities and differences between multiple inflammatory syndrome in children associated with COVID-19 and Kawasaki disease: clinical presentations, diagnosis, and treatment

BACKGROUND

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has been spreading rapidly around the world, while "multisystem inflammatory syndrome in children" (MIS-C) is a new type of syndrome that has now been reported in many countries. Similar and different characteristics between KD and MIS-C have been reported in a variety of literature. We aimed to focus on reviewing clinical presentations, diagnosis, and treatment of KD and MIS-C.

METHODS

We searched articles in the electronic databases, including the Cochrane Library database, EMBASE, and MEDLINE with the keywords "multiple inflammatory syndrome" and/or "COVID-19" and/or "Kawasaki disease" and "children".

RESULTS

Main presentations of MIS-C and KD include fever, rashes, mucous membrane involvement, conjunctivitis, hands and feet erythema/edema, and cervical lymphadenopathy. However, compared with the highest incidence of KD among some Asian countries, MIS-C is common among Black and Hispanic children. MIS-C is common in older children and teenagers, whereas classic KD is common in children under five years of age. Gastrointestinal symptoms, shock, and coagulopathy are common in MIS-C patients but are not common in classic KD. Cardiac manifestations are more common than KD, including myocarditis with cardiac dysfunction and coronary artery dilation or aneurysms. Severe cases in MIS-C present with vasodilated or cardiogenic shock that requires fluid resuscitation, muscular support, and even mechanical ventilation and extracorporeal membrane oxygenation (ECMO), whereas KD rarely presents with these manifestations and requires these treatments. Increased serum ferritin, leukopenia, lymphopenia and thrombocytopenia are common in MIS-C. However, thrombocytosis is a characteristic feature of KD. Intravenous immunoglobulin (IVIG) and moderate-high dose aspirin are still a standard recommended treatment for KD. In addition to the above-mentioned medications, steroids and biological drugs are frequently used in patients with MIS-C. Most of the children with KD have a good prognosis; however, the long-term clinical outcomes of MIS-C are not clear.

CONCLUSIONS

The overall presentation and treatment of MIS-C appear to overlap with KD. However, there are still great differences between the syndromes, and it is controversial to say whether MIS-C is a new entity or is a "severe type" of KD.