Human coronavirus-NL63 infection is not associated with acute Kawasaki disease

Emerging evidence of microbial infection in causing systematic immune vasculitis in Kawasaki disease

Kawasaki disease (KD) is a systematic vasculitis that is often complicated by coronary artery lesions and is a leading cause of acquired heart disease in developed countries. Previous studies have suggested that genetic susceptibility, together with an inducing infectious agent, could be involved in KD pathogenesis; however, the precise causative agent of this disease remains unknown. Moreover, there are still debates concerning whether KD is an infectious disease or an autoimmune disease, although many studies have begun to show that various pathogens functioning as critical inducers could activate different kinds of immune cells, consequently leading to the dysfunction of endothelial cells and systematic vasculitis. Here in this review, we attempt to summarize all the available evidence concerning pathogen infections associated with KD pathogenesis. We also discuss the related mechanisms, present a future perspective, and identify the open questions that remain to be investigated, thereby providing a comprehensive description of pathogen infections and their correlations with the host immune system in leading to KD.

A Review of Coronaviruses Associated With Kawasaki Disease: Possible Implications for Pathogenesis of the Multisystem Inflammatory Syndrome Associated With COVID-19

Multisystem Inflammatory Syndrome in Children (MIS-C), representing a new entity in the spectrum of manifestations of COVID-19, bears symptomatic resemblance with Kawasaki Disease (KD). This review explores the possible associations between KD and the human coronaviruses and discusses the pathophysiological similarities between KD and MIS-C and proposes implications for the pathogenesis of MIS-C in COVID-19. Since 2005, when a case-control study demonstrated the association of a strain of human coronavirus with KD, several studies have provided evidence regarding the association of different strains of the human coronaviruses with KD. Thus, the emergence of the KD-like disease MIS-C in COVID-19 may not be an unprecedented phenomenon. KD and MIS-C share a range of similarities in pathophysiology and possibly even genetics. Both share features of a cytokine storm, leading to a systemic inflammatory response and oxidative stress that may cause vasculitis and precipitate multi-organ failure. Moreover, antibody-dependent enhancement, a phenomenon demonstrated in previous coronaviruses, and the possible superantigenic behavior of SARS-CoV-2, possibly may also contribute toward the pathogenesis of MIS-C. Lastly, there is some evidence of complement-mediated microvascular injury in COVID-19, as well as of endotheliitis. Genetics may also represent a possible link between MIS-C and KD, with variations in FcγRII and IL-6 genes potentially increasing susceptibility to both conditions. Early detection and treatment are essential for the management of MIS-C in COVID-19. By highlighting the potential pathophysiological mechanisms that contribute to MIS-C, our review holds important implications for diagnostics, management, and further research of this rare manifestation of COVID-19.

Non-SARS, non-MERS human coronavirus infections and risk of Kawasaki disease: a meta-analysis

Aim: To study the association between non-SARS, non-MERS human coronavirus (HCoV) infections and Kawasaki disease (KD). Methods: Meta-analysis of observational studies published until 1 May 2021. Results: Out of 571 papers retrieved through database search, 10 provided data of 17,732 children. Age ranged from 2 months-14.9 years with 66% being male and 71% being complete KD. Compared with controls, there was an increased risk of developing KD in those detected to have HCoV infection (OR: 2.3 [95% CI: 1.06-4.99]; p = 0.03). The GRADE evidence for all outcomes was of 'low-certainty'. Conclusion: A 'low certainty' of evidence suggests an increased risk of KD in children infected with HCoV. We need multi-center, prospective studies to support or refute this finding. PROSPERO protocol registration: CRD42021251582.

Kawasaki Disease Shock Syndrome vs Classical Kawasaki Disease: A Meta-analysis and Comparison With SARS-CoV-2 Multisystem Inflammatory Syndrome

BACKGROUND

The emergence of increasing reports worldwide of a severe inflammatory process and shock in pediatric patients resembling Kawasaki disease (KD)-and, more specifically, Kawasaki disease shock syndrome (KDSS)-prompted us to explore KDSS in a preamble of a systematic comparison between the 2 conditions.

METHODS

We completed a systematic review of KDSS and performed a meta-analysis comparison between reported KDSS cases and KD controls.

RESULTS

A total of 10 case-control series were included in the meta-analysis. Patients with KDSS were older (38.4 ± 30.6 vs 21.9 ± 19.5 months; P < 0.001) compared with standard KD with equal sex distribution and completeness of clinical diagnostic criteria. KDSS present higher C-reactive protein (59.4 ± 29.2 mg/dL vs 20.8 ± 14.8 mg/dL; P < 0.001), lower albumin (2.7 ± 0.5 g/dL vs 3.3 ± 0.5 g/dL; P < 0.01), and lower platelets (255 ± 149 109/L vs 394 ± 132 109/L; P < 0.001) but only borderline higher white blood cells (P = 0.06). Differences in alanine transaminase, aspartate aminotransferase, and erythrocyte sedimentation rate were nonsignificant. The odds of intravenous immunoglobulin resistance (44.4% vs 9.6%; (P < 0.001) and the hospital length of stay (10.9 ± 5.8 vs 5.0 ± 3.0 days; P < 0.001) were higher in KDSS, as were the odds of coronary-artery abnormalities (33.9% vs 8.6%; P < 0.001).

CONCLUSIONS

This first meta-analysis on KDSS vs KD represents a basis for future works on KDSS and opens the opportunity for future multicentre studies in the search of causal relationships between presenting elements and the eventual complications of KDSS. The similarities between SARS-CoV-2 multisystem inflammatory syndrome in children and KDSS open new horizons to the understanding of the etiology and pathophysiology related to KDSS.

Characteristics of Children With Kawasaki Disease-Like Signs in COVID-19 Pandemic: A Systematic Review

Recent studies have shown that several children diagnosed with COVID-19 have developed Kawasaki Disease (KD)-like symptoms. This systematic review aims to assess the demographic, laboratory, and clinical characteristics of children with KD-like syndrome during the COVID-19 pandemic and evaluate efficacy of treatments and patients' outcome. A comprehensive search was carried out systematically through PubMed, Scopus, and Web of Science (WoS), medRxiv, and bioRxiv by two reviewers independently for all studies or preprints data on the demographic, laboratory, and clinical characteristics of children with K.D-like signs during the COVID-19 outbreak. Overall, 378 studies were identified by the systematic search, of which 25 studies were included in the study. The included studies involved 599 patients in total. Thirteen studies (52%) were case reports or case series, and the rest (48%) were cohort studies. In 19 studies, patients were diagnosed with Multisystem inflammatory syndrome in children (MIS-C). In 16 studies COVID-19 was diagnosed in all patients based on their polymerase chain reaction result, serological findings, and computed tomography results. Higher C-reactive protein and erythrocyte sedimentation rate level were the most prevalent laboratory findings. In most studies, patients had leucopenia with marked lymphopenia, hypoalbuminemia, and increased ferritin, as well as hyponatremia. Abnormal echocardiography and respiratory outcomes were the most common clinical outcomes. In 11 studies, all patients required intensive care unit admission. Findings of the present systematic review show that the incidence of KD-like syndrome in the COVID-19 pandemic increased significantly. Moreover, this study offers new insights in the KD-like syndrome pathogenesis and clinical spectrum during COVID-19 pandemic.

COVID-19 Inflammatory Syndrome With Clinical Features Resembling Kawasaki Disease

We describe 2 patients with coronavirus disease who had multiple clinical features suggestive of Kawasaki disease (KD). Both patients presented with fever lasting >5 days and were found to have rash, conjunctival injection, and swollen lips. One patient also had extremity swelling, whereas the other developed desquamation of the fingers. In both cases, laboratory results were similar to those seen in KD. These patients had highly unusual but similar features, and both appeared to respond favorably to treatment. It remains unclear whether these patients had true KD or manifestations of coronavirus disease that resembled KD.

Identification of new respiratory viruses in the new millennium

The rapid advancement of molecular tools in the past 15 years has allowed for the retrospective discovery of several new respiratory viruses as well as the characterization of novel emergent strains. The inability to characterize the etiological origins of respiratory conditions, particularly in children, led several researchers to pursue the discovery of the underlying etiology of disease. In 2001, this led to the discovery of human metapneumovirus (hMPV) and soon following that the outbreak of Severe Acute Respiratory Syndrome coronavirus (SARS-CoV) promoted an increased interest in coronavirology and the latter discovery of human coronavirus (HCoV) NL63 and HCoV-HKU1. Human bocavirus, with its four separate lineages, discovered in 2005, has been linked to acute respiratory tract infections and gastrointestinal complications. Middle East Respiratory Syndrome coronavirus (MERS-CoV) represents the most recent outbreak of a completely novel respiratory virus, which occurred in Saudi Arabia in 2012 and presents a significant threat to human health. This review will detail the most current clinical and epidemiological findings to all respiratory viruses discovered since 2001.

The role of infection in Kawasaki syndrome

Objectives

To analyse the evidence suggesting a possible infectious origin of Kawasaki syndrome (KS).

Methods

PubMed was searched for all of the studies published over the last 15 years using the key words “Kawasaki syndrome” or “mucocutaneous lymph node syndrome” and “infectious disease” or “genetics” or “vasculitis” or “pathogenesis”.

Results

Various levels of evidence support the hypothesis that KS is a complex disease triggered by an infection due to one or more pathogens. Viruses or bacteria may be the primum movens, although no specific infectious agent can be considered definitely etiological. A number of genetic polymorphisms have been identified in subjects with KS, but none of them can currently be considered a real marker of susceptibility.

Conclusions

Various data suggest that KS is intimately related to infectious diseases and that its clinical expression is influenced by predisposing genetic backgrounds, but our knowledge of the infectious agent(s) involved and the genetic characteristics of susceptible children remains only partial. Further studies are needed to address the many still open questions concerning the disease.

HexaPrime: a novel method for detection of coronaviruses

Despite intense efforts to develop novel and better tools to identify known viruses and to discover new viruses, establishing etiological roles for viruses in human disease is challenging. In large part, this may be attributed to the high variability of viral species and the difficulties in developing broad-spectrum, yet specific, diagnostic assays. To overcome this problem, a novel method for the detection of viruses is described in the current manuscript. The technique relies on the addition of synthetic oligonucleotides to both termini of RNA fragments in a sequence-dependent manner during first- and second-strand DNA synthesis; these oligonucleotides are used subsequently for amplification of the viral nucleic acids of interest. The recognition of the target sequence by the oligonucleotides is mediated by short (6–8 nt) conserved regions, which facilitates development of broad–spectrum assays. The method has been tested for coronaviruses, although it may be also adopted for other RNA viruses.

Development of loop-mediated isothermal amplification assay for detection of human coronavirus-NL63

Human coronavirus NL63 was identified in 2004 in the Netherlands. Due to the high prevalence and world-wide distribution of this pathogen, it is essential to develop a sensitive and specific detection assay suitable for use in a routine diagnostic laboratory. Techniques based on PCR or real-time PCR are laborious and expensive. Detailed analysis of the HCoV-NL63 genome permitted the identification of a conserved nucleic acid sequential motif, which was sufficient for the design of a loop-mediated isothermal amplification (LAMP) assay. Evaluation of the method showed that the test is specific to HCoV-NL63 and that it does not cross-react with other respiratory viruses. The detection limit was found to be 1 copy of RNA template per reaction in cell culture supernatants and clinical specimens.

Human coronaviruses 229E and NL63: close yet still so far

HCoV-NL63 and HCoV-229E are two of the four human coronaviruses that circulate worldwide. These two viruses are unique in their relationship towards each other. Phylogenetically, the viruses are more closely related to each other than to any other human coronavirus, yet they only share 65% sequence identity. Moreover, the viruses use different receptors to enter their target cell. HCoV-NL63 is associated with croup in children, whereas all signs suggest that the virus probably causes the common cold in healthy adults. HCoV-229E is a proven common cold virus in healthy adults, so it is probable that both viruses induce comparable symptoms in adults, even though their mode of infection differs. Here, we present an overview of the current knowledge on both human coronaviruses, focusing on similarities and differences.

Emerging respiratory agents: new viruses for old diseases?

The recent advances in molecular technology have enabled the detection of several new viral agents in specimens collected from the human respiratory tract. Human metapneumovirus was first described in 2001, and is a significant respiratory pathogen, particularly of children. Following the identification of severe acute respiratory syndrome (SARS) associated coronavirus, two other newly detected coronaviruses, NL63 and HKU1, have been linked to respiratory disease in humans. However, identifying a new virus as the causative agent of a specific disease is difficult, and ideally would involve satisfying Koch's postulates. The recently described human bocavirus and polyomaviruses KI and WU have been detected in samples collected from humans with acute respiratory infection, but as yet, have not been conclusively proven to be agents of human disease.

We review the new viral agents that have been detected in respiratory samples since 2001, and examine their contribution as agents of human disease.

Acute life threatening event (ALTE) in an infant with human coronavirus HCoV-229E infection

In this short report we discuss the temporal association between an acute life threatening event (ALTE) and a RT-PCR confirmed coronavirus HCoV-229E infection in a 4 months old otherwise healthy infant. More detailed microbiological investigations of affected children even without apparent signs of a respiratory tract infection may help to clarify the etiology in some patients and extend our understanding of the pathogenesis. PCR-based techniques should be utilized to increase the sensitivity of detection for old and new respiratory viral pathogens in comparable cases.