Search Results (79)

Although Kawasaki disease (KD) has been known since 1967, when it was first described by Dr. Tomisaku Kawasaki, the literature indicates that its etiology—similarly to Multisystem Inflammatory Syndrome in Children (MIS-C)—remains largely unclear and is the subject of intensive research. The former disease, which typically occurs shortly after infection, is the most common cause of primary vasculitis in children worldwide. The latter—MIS-C, associated with SARS-CoV-2 infection—is characterized by involvement of at least two organ systems. Undoubtedly, both diseases exhibit heightened immune system activity and significant inflammation. In recent years, increasing attention has been directed towards alterations in the microbiota observed in affected patients. We undertake an analysis and systematic review of the current scientific findings in this field. We emphasize the role of the microbiome—which encompasses not only bacteria but also viruses, fungi, parasites, and archaea—in health and disease. We track its composition from birth and highlight factors influencing its diversity, such as the mode of delivery. We recognize the microbiome’s role in reducing the likelihood of allergic diseases in children and its interactions with the immune system. In addition to comparing the pathomechanisms and clinical manifestations of KD and MIS-C, also known as Pediatric Inflammatory Multisystem Syndrome (PIMS), we investigate microbiota alterations in these conditions and analyze potential applications of microbiome knowledge, for example, in identifying diagnostic markers. We also point out potential directions for future research, such as the use of short-chain fatty acids (SCFAs) in MIS-C and the long-term changes in the gut microbiota associated with these diseases, which remain poorly documented and currently represent significant gaps in knowledge. Full article

Multisystem inflammatory syndrome in children (MIS-C), also known as pediatric inflammatory multisystem syndrome (PIMS), presents significant challenges in pediatric cardiology, due to its complex molecular pathophysiology. In this retrospective analysis of 15 cases that were managed at a single tertiary care center, we investigated the molecular contributors to myocardial dysfunction, including cytokine storms, hyperinflammation markers, and hypercoagulable states. Transient myocardial involvement was identified in 46.6% of patients, with complete recovery achieved within 2–4 weeks following treatment. Ferritin, NT-ProBNP, and troponin levels were significantly elevated in patients with ventricular dysfunction compared to those without. The neutrophil-to-lymphocyte ratio (NLR), which was previously identified as a severity marker in acute COVID-19, was also significantly higher in patients with ventricular dysfunction, suggesting its potential as a prognostic indicator in MIS-C. Notably, no coronary artery aneurysms were detected in the cohort. These findings underscore the importance of early, standardized therapeutic interventions in mitigating severe outcomes, and they provide valuable insights into the molecular mechanisms driving myocardial dysfunction in MIS-C. Incorporating NLR and ferritin into the initial diagnostic workup may improve the early triage and identification of high-risk MIS-C patients. Full article

Background: Macrophage activation syndrome (MAS) is a hyperinflammatory and potentially fatal complication associated with rheumatologic disorders. In Kawasaki disease (KD), MAS is a rare and poorly described condition, making its differentiation from a severe, treatment-resistant presentation of KD particularly challenging. Objective: We aimed to describe MAS in KD by analyzing its epidemiological, clinical, and laboratory characteristics, complications, therapeutic strategies, and outcomes. Methods: A comprehensive literature review of PubMed, Embase, Scopus, and Cochrane Library was conducted to identify English-language studies on KD complicated by MAS, including case reports and case series, until 15 November 2024. Results: A total of 176 pediatric patients (60 females; median age 4 years, range 0.13–17) from 48 articles were included. MAS occurred after or simultaneously with KD diagnosis in 174/176 cases (99%). Common features included fever (100%), splenomegaly (49.4%), and hyperferritinemia (98.2%). Cardiac involvement was reported in 37% of children. The HLH-2004 criteria were met in 63% of cases, while the 2016 Ravelli criteria for MAS complicating systemic juvenile idiopathic arthritis were met in 94%. Treatment included additional doses of IVIG (36.2%), GCs (82.8%), cyclosporine A (28.7%), and biologics (13.8%), with complete MAS resolution in 93% of cases. Conclusions: MAS in KD is a rare but severe complication, with overlapping features that make its differentiation from severe and resistant KD challenging. Persistent fever despite initial IVIG administration, along with splenomegaly and hyperferritinemia, emerge as key warning signs. Ravelli criteria provide stronger diagnostic support compared to the HLH-2004 criteria. Moreover, MAS is associated with increased cardiac involvement. Full article

Background/Objectives: To investigate if the severity and presentation of multisystem inflammatory syndrome in children (MIS-C) vary between different severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants. Methods: This retrospective study included 59 patients aged 0–18 years, diagnosed with COVID-19 and MIS-C, treated and monitored over a one-year period after discharge from hospital. The patients were grouped according to the predominant SARS-CoV-2 variant. The predominant variant of SARS-CoV-2 was assumed by the date of hospitalization. The following patient data were collected: demographic data (age, sex), information on comorbidities, body mass index, clinical data (fever and duration of febrile periods, symptoms of Kawasaki-like phenotypes, and presence of respiratory, cardiovascular, gastrointestinal, neurological and other symptoms), and laboratory and imaging findings. Results: In total, 24 (41%), 19 (32%), and 15 (25%) patients were diagnosed with MIS-C during the Alpha, Delta, and Omicron periods, respectively (63.8% were males; 36.2% were females). Comorbidities were present in 49% of patients. Respiratory symptoms were the most common during the Delta period (73%, p = 0.028). There was no statistically significant difference in the occurrence of other symptoms, laboratory findings, treatment, complications, and long-term outcomes between groups. Conclusions: No significant correlation was found between hospitalization date (used to estimate COVID-19 variant) and presentation/severity of MIS-C. Full article

Background and Objectives: Due to its link with the SARS-CoV-2, Multisystem Inflammatory Syndrome in Children (MIS-C) gained global attention as a serious condition that requires hospital care. Our study aimed to present the clinical and laboratory characteristics of MIS-C patients by age group and intensive care unit (ICU) admission status and assess early echocardiographic changes. Materials and Methods: A single-center partly retrospective, partly prospective observational cohort study was performed from December 2020 to June 2024. The study included 42 patients aged between 1 month and 18 years who were diagnosed with MIS-C and gave informed consent. Results: The median age was 6.5 years (IQR 2.0–9.3). The predominant symptoms were cardiovascular (88.1%), mucocutaneous (85.7%) and gastrointestinal (76.2%). Five children (11.9%) developed shock. About two-thirds of patients (66.7%) were admitted to the ICU. Adolescents (≥12 years) were less likely to exhibit mucocutaneous or cardiovascular symptoms and thus less frequently having Kawasaki—like disease symptoms compared with other age groups (<5 years or 5–11 years). Lymphopenia was more common among patients aged 5 years and older. Adolescents had higher procalcitonin (PCT) and a lower estimated glomerular filtration rate. Troponin I and B-type natriuretic peptide (BNP) levels were higher in children aged 5–11 years, while ferritin levels were lower among the youngest (<5 years). Patients treated at the ICU were more likely to have cardiovascular and respiratory symptoms, as well as a history of symptomatic COVID-19, higher C-reactive protein (CRP), PCT, BNP and lower albumin levels. Echocardiographic abnormalities were found in 71.4% of cases. During hospitalization, left ventricular ejection fraction values increased significantly (p < 0.001) over 12 (IQR 9.0–14.0) days. Conclusions: Symptoms and laboratory markers of MIS-C vary according to age. Higher CRP, PCT, BNP and hypoalbuminemia are predictors of MIS-C severity. Cardiovascular involvement is common and might be severe, but rapid resolution is encouraging. Full article

Objectives: The purpose of this study was to compare and contrast Kawasaki disease (KD) with multisystem inflammatory syndrome in children (MIS-C) during the SARS-CoV-2 pandemic. Methods: A retrospective analysis of the medical records of patients diagnosed with KD and MIS-C at a single institution from July 2020 to November 2021 was performed. Results: The study included 39 MIS-C patients (84.6% male) with a median age of 138 months and 17 KD patients (58.8% male) with a median age of 36 months. The MIS-C patients were older (p < 0.001) and had prolonged hospitalizations (p = 0.023), elevated neutrophil counts (p < 0.001), C-reactive protein (p < 0.001), procalcitonin (p < 0.001), interleukin-6 (p < 0.014), ferritin (p < 0.001), fibrinogen (p < 0.001), troponin I (p = 0.001), NT-proBNP (p < 0.001), and D-dimer levels (p < 0.001). There were more cases of hypotension (p = 0.024), decreased left ventricular function (p = 0.023), and a greater need for corticosteroids (p < 0.001), enoxaparin (p = 0.045), and therapeutic plasma exchange (p < 0.001). Kawasaki disease patients had a greater incidence of rash (p < 0.001), changes in oral mucosa (p < 0.001), conjunctival injection (p < 0.001), extremity changes (p < 0.001), and cervical lymphadenopathy (p < 0.001). They had a longer duration of fever (p < 0.001), elevated white blood cell count (p < 0.001), platelet count (p < 0.001), and alanine aminotransferase level (p < 0.001). The two groups were similar regarding the hemoglobin levels, erythrocyte sedimentation rates, albumin levels, and the frequency of coronary aneurysm, myocarditis, pericarditis, invasive mechanical ventilatory support, and intravenous immunoglobulin treatment. Conclusions: Advanced patient age, a greater presence of gastrointestinal and cardiac findings associated with hypotension, increased NT-proBNP levels, decreased left ventricular function, the use of various treatment modalities, and longer hospital stays suggest MIS-C, whereas prolonged fever and classical clinical features of KD favor KD. Full article

Background/Objectives: Multisystem Inflammatory Syndrome in Children (MIS-C) is a post-infectious complication of COVID-19. MIS-C has overlapping features with other pediatric inflammatory disorders including Kawasaki Disease (KD), Macrophage Activation Syndrome (MAS), Toxic Shock Syndrome and sepsis. The exact mechanisms responsible for the clinical overlap between MIS-C and these conditions remain unclear, and biomarkers that could distinguish MIS-C from its clinical mimics are lacking. This study aimed to provide an overview of how proteomic methods, like Mass Spectrometry (MS) and affinity-based proteomics, can offer a detailed understanding of pathophysiology and aid in the diagnosis and prognosis of MIS-C. Methods: A narrative review of relevant studies published up to July 2024 was conducted. Results: We identified 15 studies and summarized their key proteomic findings. These studies investigated the serum or plasma proteome of MIS-C patients using MS, Proximity Extension, or Aptamer-based assays. The studies associated the proteomic profile of MIS-C with laboratory and clinical parameters and/or compared it with that of other diseases including acute COVID-19, KD, MAS, pediatric rheumatic diseases, sepsis and myocarditis or pericarditis following COVID-19 mRNA immunization. Depending on the method and the control group, different proteins were increased or decreased in the MIS-C group. The limitations and challenges in MIS-C proteomic research are also discussed, and future research recommendations are provided. Conclusions: Although proteomics appear to be a promising approach for understanding the pathogenesis and uncovering candidate biomarkers in MIS-C, proteomic studies are still needed to recognize and validate biomarkers that could accurately discriminate MIS-C from its clinical mimics. Full article

Background: Kawasaki disease (KD) is a pediatric vasculitis, leading to coronary artery aneurysms (CAAs) in ~4–14%. Attention to the etiology and course of KD was generated by the close mimic of a SARS-CoV-2-induced phenotype, called multisystem inflammatory syndrome in children (MIS-C). Methods: A total of 1179 cases were collected from 2012 with ~50% of cases retrospectively included. Clinical characteristics were described and risk factors for CAA (persistence) were investigated. Phenotypic patterns of the prospectively included KD patients were evaluated. These patterns were also compared to the seronegative KD and seropositive MIS-C cases identified during the SARS-CoV-2 pandemic. Results: KD mostly affected boys and children < 5 years. IVIG resistance, CAAs, and giant CAAs occurred in 24.5%, 21.4%, and 6.6%, respectively. Giant CAAs were significantly more likely to normalize to a normal Z score in patients that were younger than 2.5 years old at the time of initial giant CAA (χ² test p = 0.02). In our prospective (SARS-CoV-2-seronegative) KD series, there was a diminishing male predominance over time, whereas the proportions of incomplete presentations (p < 0.001) and patients with circulatory shock (p = 0.04) increased since the COVID-19 pandemic. Pre- and post-pandemic KD cases presented with different levels of C-reactive protein, thrombocyte counts, and hemoglobin levels over the years. Compared to pandemic KD, SARS-CoV-2-seropositive MIS-C patients were older (p < 0.001), and more often required intensive care admission (p < 0.001), with a gradual decrease over time between 2020 and 2022 (p = 0.04). KD carried a substantial risk of CAA development in contrast to MIS-C. Conclusion: the phenotypic changes seen over the last twelve years of our prospective follow-up study suggest a spectrum of hyperinflammatory states with potentially different triggering events within this clinical entity. Full article

Multisystem inflammatory syndrome in children (MIS-C) is a disease that made its mark in the early days of the COVID-19 pandemic due to the diverse course and symptoms affecting multiple body systems. It is a condition that develops in pediatric patients about 2–6 weeks after contact with a person infected with the SARS-CoV-2 virus. In many instances, MIS-C has caused multiple organ failure, with particularly severe complications involving the cardiovascular system and manifesting as hypotension, various cardiac arrhythmias, myocarditis or coronary artery lesions resembling those seen in Kawasaki disease. Currently, the incidence of MIS-C is about 1–3 per 1000 children, with a decreasing trend in recent years due to the introduction of immunization against the SARS-CoV-2 virus for children as young as 6 months. In our paper, we present the case of a patient with a severe course of MIS-C with numerous cardiovascular and neurological complications, in whom the symptoms of the disease were managed by administering biological treatment. We also present a review of the literature on the subject, which shows how many different facets this disease can have and that physicians still need to remain alert, as there are cases of severe MIS-C, especially in unvaccinated patients. Full article

Background: Kawasaki disease (KD) is a syndrome primarily affecting young children, typically under the age of five, and is characterized by the development of acute vasculitis. Through extensive research conducted on both murine and human subjects, it has been demonstrated that heightened levels of reactive oxygen species (ROS) play a pivotal role in the development of KD, especial coronary artery lesions (CALs). Hydrogen gas exhibits potent antioxidant properties that effectively regulate ROS production and the inflammatory response. Methods: We used Lactobacillus casei cell wall extract (LCWE)-induced vasculitis in mice as an animal model of KD and treated the mice with hydrogen gas inhalation. Results: We observed significant dilatation and higher Z scores in the left coronary artery (LCA) in D21 and D28 in mice after LCWE treatment compared to the control group (p < 0.001) and a significant resolution of LCA diameters (p < 0.01) and Z scores (p < 0.01) after treatment with inhaled hydrogen gas. We further demonstrated that serum IL-6 expression was higher in mice after LCWE treatment (p < 0.01) and IL-6 significantly decreased after inhaled hydrogen gas therapy (p < 0.001). Conclusion: According to our literature review, this is the first report where hydrogen gas inhalation has been demonstrated to be effective for the treatment of coronary artery dilatation in a KD murine model. Full article

Systemic vasculitides are a rare and complex group of diseases that can affect multiple organ systems. Clinically, presentation may be vague and non-specific and as such, diagnosis and subsequent management are challenging. These entities are typically classified by the size of vessel involved, including large-vessel vasculitis (giant cell arteritis, Takayasu’s arteritis, and clinically isolated aortitis), medium-vessel vasculitis (including polyarteritis nodosa and Kawasaki disease), and small-vessel vasculitis (granulomatosis with polyangiitis and eosinophilic granulomatosis with polyangiitis). There are also other systemic vasculitides that do not fit in to these categories, such as Behcet’s disease, Cogan syndrome, and IgG4-related disease. Advances in medical imaging modalities have revolutionized the approach to diagnosis of these diseases. Specifically, color Doppler ultrasound, computed tomography and angiography, magnetic resonance imaging, positron emission tomography, or invasive catheterization as indicated have become fundamental in the work up of any patient with suspected systemic or localized vasculitis. This review presents the key diagnostic imaging modalities and their clinical utility in the evaluation of systemic vasculitis. Full article

Background: Vasculitis diseases include Kawasaki disease (KD), Kawasaki disease shock syndrome (KDSS), Multisystem Inflammatory Syndrome (MIS), Henoch–Schönlein purpura (HS), or IgA vasculitis, and additional vasculitis diseases. These diseases are often preceded by infections or immunizations. Disease incidence rates are higher in children than in adults. These diseases have been extensively studied, but understanding of the disease etiology remains to be established. Objective: Many studies have failed to demonstrate an association between vasculitis diseases and vaccination; this study examines possible associations. Methods: Herein, the Vaccine Adverse Event Reporting System (VAERS) database is retrospectively examined for associations between vasculitis diseases and immunizations. Results: For some vaccines, the number of rare cases of KD, MIS, and HS are higher than the background rates. These rare cases are predicted to occur in individuals with (1) genetic risk factors with (2) antibody titer levels above the primary immune response level. Herein, the model of humoral immune response antibodies bound to antigens (pathogen or vaccine) creating immune complexes is proposed. These immune complexes are proposed to bind Fc receptors on immune cells and platelets, resulting in cell activation and the release of inflammatory molecules including histamine and serotonin. Immune complexes and inflammatory molecules including serotonin and histamine likely trigger vasculitis. Elevated serotonin and possibly histamine drive initial vasoconstrictions, disrupting blood flow. Increased blood flow pressure from cardiac capillary vasoconstrictions is predicted to trigger coronary artery aneurysms (CAA) or lesions (CAL) in some patients. For KDSS and MIS patients, these cardiac capillary vasoconstrictions are predicted to result in ischemia followed by ventricular dysfunction. Ongoing ischemia can result in long-term cardiac damage. Cases associated with pathogens are likely to have persistent infections triggering disease onset. Conclusion: The proposed model of immune complexes driving disease initial disease etiology by Fc receptor activation of immune cells and platelets, resulting in elevated histamine and serotonin levels, is testable and is consistent with disease symptoms and current treatments. Full article

This study examined the distinctions between multisystem inflammatory syndrome associated with coronavirus disease 2019, Kawasaki disease, and infectious mononucleosis. These three inflammatory disorders have commonalities according to clinical and laboratory results, particularly in relation to eosinophil levels. In this retrospective, single-center study, we documented the examination records (acute phase reactants and complete blood count) and clinical and cardiological findings of 130 patients diagnosed with multisystem inflammatory syndrome, Kawasaki disease, and infectious mononucleosis. These patients were treated and received follow-up care in our hospital from March 12, 2020, to September 13, 2022, as per the hospital records. Statistical analyses were performed using NCSS 2007, version 1 software. Eosinopenia was more prevalent in children with multisystem inflammatory syndrome than in those with Kawasaki disease, who showed normal or elevated eosinophil counts. The eosinophil counts in patients with infectious mononucleosis typically fell within the normal range. Our study found no correlation between the eosinophil counts and cardiac involvement in pediatric patients with either condition. These findings indicate a higher prevalence of eosinopenia in patients with multisystem inflammatory syndrome, irrespective of cardiac involvement, than in those with Kawasaki disease. Despite similarities in clinical findings, Kawasaki disease and multisystem inflammatory syndrome in children necessitate further studies for distinct characteristic elucidation. Full article

Kawasaki disease (KD) is an acute febrile vasculitis that occurs mostly in children younger than five years. KD involves multiple intricately connected inflammatory reactions activated by a cytokine cascade. Despite therapeutic advances, coronary artery damage may develop in some patients, who will be at risk of clinical cardiovascular events and even sudden death. The etiology of KD remains unclear; however, it may involve both genetic and environmental factors leading to aberrant inflammatory responses. Given the young age of onset, prenatal or perinatal exposure may be etiologically relevant. Multisystem inflammatory syndrome in children, a post-infectious hyper-inflammatory disorder associated with severe acute respiratory syndrome coronavirus 2, has features that overlap with those of KD. Available evidence indicates that vascular endothelial dysfunction is a critical step in the sequence of events leading to the development of cardiovascular lesions in KD. Oxidative stress and the dysregulation of the nitric oxide (NO) system contribute to the pathogenesis of inflammatory responses related to this disease. This review provides current evidence and concepts highlighting the adverse effects of oxidative injury and NO system derangements on the initiation and progression of KD and potential therapeutic strategies for cardiovascular pathologies in affected children. Full article

Multisystem inflammatory syndrome in children (MIS-C) is a postinfectious sequela of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), with some clinical features overlapping with Kawasaki disease (KD). Our research group and others have highlighted that the spike protein of SARS-CoV-2 can trigger the activation of human endogenous retroviruses (HERVs), which in turn induces inflammatory and immune reactions, suggesting HERVs as contributing factors in COVID-19 immunopathology. With the aim to identify new factors involved in the processes underlying KD and MIS-C, we analysed the transcriptional levels of HERVs, HERV-related genes, and immune mediators in children during the acute and subacute phases compared with COVID-19 paediatric patients and healthy controls. The results showed higher levels of HERV-W, HERV-K, Syn-1, and ASCT-1/2 in KD, MIS-C, and COV patients, while higher levels of Syn-2 and MFSD2A were found only in MIS-C patients. Moreover, KD and MIS-C shared the dysregulation of several inflammatory and regulatory cytokines. Interestingly, in MIS-C patients, negative correlations have been found between HERV-W and IL-10 and between Syn-2 and IL-10, while positive correlations have been found between HERV-K and IL-10. In addition, HERV-W expression positively correlated with the C-reactive protein. This pilot study supports the role of HERVs in inflammatory diseases, suggesting their interplay with the immune system in this setting. The elevated expression of Syn-2 and MFSD2A seems to be a distinctive trait of MIS-C patients, allowing to distinguish them from KD ones. The understanding of pathological mechanisms can lead to the best available treatment for these two diseases, limiting complications and serious outcomes. Full article