Th1 and Th2 cytokine production is suppressed at the level of transcriptional regulation in Kawasaki disease

Integration of scRNA-Seq and bulk RNA-Seq uncover perturbed immune cell types and pathways of Kawasaki disease

Introduction

Kawasaki disease (KD) is an acute febrile illness primarily affecting children and characterized by systemic inflammation and vasculitis that can lead to coronary artery complications. The aim of this study was to gain a comprehensive understanding of immune dysregulation in KD.

Methods

To this end, we employed integration of single-cell RNA sequencing (scRNA-Seq) and bulk RNA sequencing (bulk RNA-Seq) data. Furthermore, we conducted flow cytometry analysis for a cohort of 82 KD patients.

Results

Our analysis revealed significant heterogeneity within immune cell populations in KD patients, with distinct clusters of T cells, B cells, and natural killer (NK) cells. Importantly, CD4+ naïve T cells in KD patients were found to predominantly differentiate into Treg cells and Th2 cells, potentially playing a role in the excessive inflammation and vascular damage characteristic of the disease. Dysregulated signaling pathways were also identified, including the mTOR signaling pathway, cardiomyopathy pathway, COVID-19 signaling pathway, and pathways involved in bacterial or viral infection.

Discussion

These findings provide insights into the immunopathogenesis of KD, emphasizing the importance of immune cell dysregulation and dysregulated signaling pathways. Integration of scRNA-Seq and bulk RNA-Seq data offers a comprehensive view of the molecular and cellular alterations in KD and highlights potential therapeutic targets for further investigation. Validation and functional studies are warranted to elucidate the roles of the identified immune cell types and pathways in KD pathogenesis and to develop targeted interventions to improve patient outcomes.

Intravenous Immunoglobulin Therapy Restores the Quantity and Phenotype of Circulating Dendritic Cells and CD4+ T Cells in Children With Acute Kawasaki Disease

Background

Intravenous immunoglobulin (IVIG) showed its therapeutic efficacy on Kawasaki disease (KD). However, the mechanisms by which it reduces systemic inflammation are not completely understood. Dendritic cells (DCs) and T cells play critical roles in the pathogenic processes of immune disorders. Assessing the quantity of DC subsets and T cells and identifying functional molecules present on these cells, which provide information about KD, in the peripheral blood may provide new insights into the mechanisms of immunoglobulin therapy.

Methods

In total, 54 patients with KD and 27 age-matched healthy controls (HCs) were included in this study. The number, percentage, and phenotype of DC subsets and CD4⁺ T cells in peripheral blood were analyzed through flow cytometry.

Results

Patients with KD exhibited fewer peripheral DC subsets and CD4⁺ T cells than HCs. Human leucocyte antigen-DR (HLA-DR) expression was reduced on CD1c⁺ myeloid DCs (CD1c⁺ mDCs), whereas that on plasmacytoid DCs (pDCs) did not change significantly. Both pDCs and CD1c⁺ mDCs displayed significantly reduced expression of co-stimulatory molecules, including CD40, CD86. pDCs and CD1c⁺ mDCs presented an immature or tolerant phenotype in acute stages of KD. Number of circulating pDC and CD1c⁺ mDC significantly inversely correlated with plasma interleukin-6 (IL-6) levels in KD patients pre-IVIG treatment. No significant differences were found concerning the DC subsets and CD4⁺ T cells in patients with KD with and without coronary artery lesions. Importantly, these altered quantity and phenotypes on DC subsets and CD4⁺ T cells were restored to a great extent post-IVIG treatment. T helper (Th) subsets including Th1 and Th2 among CD4⁺ T cells did not show alteration pre- and post-IVIG treatment, although the Th1-related cytokine IFN-γ level in plasma increased dramatically in patients with KD pre-IVIG treatment.

Conclusions

pDCs and CD1c⁺ mDCs presented an immature or tolerant phenotype in acute stages of KD, IVIG treatment restored the quantity and functional molecules of DCs and CD4⁺ T cells to distinct levels in vivo, indicating the involvement of DCs and CD4⁺ T cells in the inflammation in KD. The findings provide insights into the immunomodulatory actions of IVIG in KD.

The Impact of Moderate-Dose Acetylsalicylic Acid in the Reduction of Inflammatory Cytokine and Prevention of Complication in Acute Phase of Kawasaki Disease: The Benefit of Moderate-Dose Acetylsalicylic Acid

Background: Acetylsalicylic acid (ASA) is part of the recommended treatment of Kawasaki disease (KD). Controversies remain regarding the optimal dose of ASA. We aimed to evaluate the impact of different doses of ASA on inflammation control while minimizing adverse effects in the acute phase treatment of KD. Methods: The enrolled 323 patients with KD were divided into three groups according to ASA dose: moderate-dose (30–50 mg/kg/day), high-dose (80–100 mg/kg/day), and non-ASA. Results: High-dose ASA group showed a significantly shorter duration of fever from the start of treatment to remission than other groups. Baseline level and delta score of interleukin (IL)-1, IL-6, IL-10, tumor necrosis factor-α, and transforming growth factor β were not statistically different among the groups. The number of patients who received additional treatments in the non-ASA group was more than other groups. Coronary artery dilatation was not significantly different among the groups. One patient with high-dose ASA was diagnosed with Reye syndrome. Conclusion: Different doses of ASA did not show any differences in changes of inflammatory bio-makers and cytokines. However, high-dose ASA showed occurrence of Reye syndrome, and non-ASA showed intravenous immunoglobulin refractoriness. We suggest that moderate-dose ASA may be beneficial for the treatment of patients in the acute phase of KD.

Effects of changes on gut microbiota in children with acute Kawasaki disease

Background

Kawasaki disease (KD) is an acute febrile illness of early childhood. The exact etiology of the disease remains unknown. At present, research on KD is mostly limited to susceptibility genes, infections, and immunity. However, research on the correlation between gut microbiota and KD is rare.

Methods

Children with a diagnosis of acute KD and children undergoing physical examination during the same period were included. At the time of admission, the subjects’ peripheral venous blood and feces were collected. Faecal samples were analyzed for bacterial taxonomic content via high-throughput sequencing. The abundance, diversity, composition, and characteristic differences of the gut microbiota in KD and healthy children were compared by alpha diversity, beta diversity, linear discriminant analysis and LDA effect size analysis. Blood samples were used for routine blood examination, biochemical analysis, and immunoglobulin quantitative detection.

Results

Compared with the control group, the community richness and structure of gut microbiota in the KD group was significantly reduced (Chao1 richness estimator, mean 215.85 in KD vs. mean 725.76 in control, p < 0.01; Shannon diversity index, mean 3.32 in KD vs. mean 5.69 in control, p < 0.05). LEfSe analysis identified two strains of bacteria significantly associated with KD: Bacteroidetes and Dorea. Bacteroidetes were enriched in healthy children (mean 0.16 in KD vs. mean 0.34 in control, p < 0.05). Dorea was also enriched in healthy children but rarely existed in children with KD (mean 0.002 in KD vs. mean 0.016 in control, p < 0.05). Compared with the control, IgA and IgG in the KD group decreased (IgA, median 0.68 g/L in KD vs. median 1.06 g/L in control, p < 0.001; IgG, median 6.67 g/L in KD vs. median 9.71 g/L in control, p < 0.001), and IgE and IgM levels were not significantly changed.

Conclusions

Dysbiosis of gut microbiota occurs in children with acute KD and may be related to the etiology or pathogenesis of KD. It is worth noting that for the first time, we found that Dorea, a hydrogen-producing bacterium, was significantly reduced in children with acute KD. Overall, our results provide a theoretical basis for the prevention or diagnosis of KD based on intestinal microecology.

Acute hepatitis B virus infection model within the host incorporating immune cells and cytokine responses

We formulate and analyze a within-host hepatitis B viral mathematical model for hepatitis B in the acute phase of infection. The model incorporates hepatocytes, hepatitis B virus, immune system cells and cytokine dynamics using a system of ordinary differential equations. We use the model to demonstrate the trends of the hepatitis B infection qualitatively without the effects of immune cells and cytokines. Using these trends, we tested the effects of incorporating the immune cells only and immune cells with cytokine responses at low and high inhibitions on the hepatitis B virus infection. Our results showed that it is impossible to have the immune cells work independently from cytokines when there is an acute hepatitis B virus infection. Therefore, our results suggest that incorporating immune cells and cytokine dynamics in the acute hepatitis B virus infection stage delays infection in the hepatocytes and excluding such dynamics speeds up infection during this phase. Results from this study are useful in developing strategies for control of hepatocellular carcinoma which is caused by hepatitis B virus infection.

MiR-182-5p enhances in vitro neutrophil infiltration in Kawasaki disease

Background

Kawasaki disease (KD) patients could develop coronary artery lesion (CAL) which threatens children's life. A previous study identified KD biomarker miRNAs that could discriminate KD patients from febrile non‐KD patients. We wonder whether these KD prediction biomarkers could be further applied to predict CAL formation in KD patients.

Methods

To examine this hypothesis, we conducted a meta‐analysis, miRNA mimic transfection, in vitro cell model and microarray assays.

Results

We first showed that miR‐182‐5p and miR‐183‐5p kept higher levels in the KD patients with CAL than those without CAL (p < .05). Further machine learning alignment confirmed that CAL formation could be predicted, with an auROC value of 0.86. We further treated neutrophil cells with miR‐182‐5p mimic, followed by in vitro transendotherial migration assay. As a result, miR‐182‐5p overexpression significantly (p < .05) enhanced neutrophil cells to infiltrate the endothelial layer composed of human coronary artery endothelium cells. Further microarray assay and pathway enrichment analysis showed that the genes activated with miR‐182‐5p overexpression were significantly enriched in the leukocyte transendothelial migration pathway (kegg_pathway_194, p < .05).

Conclusion

Therefore, our study suggested that miR‐182‐5p enhanced in vitro leukocyte infiltration by activating the leukocyte transendothelial migration pathway in CAL formation in KD.

A low-frequency IL4R locus variant in Japanese patients with intravenous immunoglobulin therapy-unresponsive Kawasaki disease

BACKGROUND

Kawasaki disease (KD) is a systemic vasculitis which may be associated with coronary artery aneurysms. A notable risk factor for the development of coronary artery aneurysms is resistance to intravenous immunoglobulin (IVIG) therapy, which comprises standard treatment for the acute phase of KD. The cause of IVIG resistance in KD is largely unknown; however, the contribution of genetic factors, especially variants in immune-related genes, has been suspected.

METHODS

To explore genetic variants related to IVIG-unresponsiveness, we designated KD patients who did not respond to both first and second courses of IVIG therapy as IVIG-unresponsive patients. Using genomic DNA from 30 IVIG-unresponsive KD patients, we performed pooled genome sequencing targeting 39 immune-related cytokine receptor genes.

RESULTS

The single nucleotide variant (SNV), rs563535954 (located in the IL4R locus), was concentrated in IVIG-unresponsive KD patients. Individual genotyping showed that the minor allele of rs563535954 was present in 4/33 patients with IVIG-unresponsive KD, compared with 20/1063 individuals in the Japanese genome variation database (odds ratio = 7.19, 95% confidence interval 2.43-21.47). Furthermore, the minor allele of rs563535954 was absent in 42 KD patients who responded to IVIG treatment (P = 0.0337), indicating that a low-frequency variant, rs563535954, is associated with IVIG-unresponsiveness in KD patients. Although rs563535954 is located in the 3'-untranslated region of IL4R, there was no alternation in IL4R expression associated with the mior allele of rs563535954. However, IVIG-unresponsive patients that exhibited the minor allele of rs563535954 tended to be classified into the low-risk group (based on previously reported risk scores) for prediction of IVIG-resistance. Therefore, IVIG-unresponsiveness associated with the minor allele of rs563535954 might differ from IVIG-unresponsiveness associated with previous risk factors used to evaluate IVIG-unresponsiveness in KD.

CONCLUSION

These findings suggest that the SNV rs563535954 could serve as a predictive indicator of IVIG-unresponsiveness, thereby improving the sensitivity of risk scoring systems, and may aid in prevention of coronary artery lesions in KD patients.

Downregulation of Transcription Factor T-Bet as a Protective Strategy in Monosodium Urate-Induced Gouty Inflammation

Gout is sterile joint inflammation triggered by the damaging effects of monosodium urate (MSU) crystals accumulation. Previous studies suggest transcription factor T-bet plays an important role in inflammatory arthritis. Notably, mice lacking T-bet markedly reduced joint inflammation of rheumatoid arthritis models, however, the involvement of T-bet in gouty inflammation has yet to be clarified. Here, we took advantage of T-bet knockout (KO) mice to investigate the role of T-bet in the pathogenesis of MSU-induced gout inflammation. T-bet KO and wild type (WT) mice were used for models of acute inflammation induced with MSU crystals, including footpad, air pouch and peritonitis models. Inflammatory cytokines and phagocytosis were detected in bone-marrow-derived macrophages (BMDMs) from T-bet KO and WT mice treated with MSU crystals in vitro. In addition, T-bet expression in peripheral blood mononuclear cells (PBMCs) from gout patients was measured, as well as plasma inflammatory cytokines. We found that the levels of interleukin (IL)-17, IL-23, and interferon-γ were reduced, but tumor necrosis factor-α was not, in BMDMs from T-bet KO compared with WT mice after MSU challenge in vitro, as well as MSU phagocytosis. In comparison with WT mice in vivo, the swelling index of T-bet KO mice was significantly decreased in the footpad model. T-bet deficiency also dramatically relieved MSU-induced inflammatory cell infiltration in peritonitis and air pouch models in vivo, and as well as the IL-1β levels of air pouch lavage fluid (APLF). In addition, plasma IL-17 and IL-23 levels were elevated in acute gout, whereas protein levels of T-bet were downregulated in PBMCs from acute gout patients and intercritical gout treated with MSU crystals in vitro as well. Transcription factor T-bet deficiency protects against MSU-induced gouty inflammation, suggesting that downregulation of T-bet could be a protective strategy and contribute to spontaneous remission of inflammation in acute gout.

Biomarkers for Kawasaki Disease: Clinical Utility and the Challenges Ahead

Kawasaki disease (KD) has replaced acute rheumatic fever as the most common cause of acquired heart disease in children in the developed world and is increasingly being recognized from several developing countries. It is a systemic vasculitis with a predilection for coronary arteries. The diagnosis is based on a constellation of clinical findings that appear in a temporal sequence. Quite understandably, this can become a problem in situations wherein the clinical features are not typical. In such situations, it can be very difficult, if not impossible, to arrive at a diagnosis. Several biomarkers have been recognized in children with acute KD but none of these has reasonably high sensitivity and specificity in predicting the course of the illness. A line up of inflammatory, proteomic, gene expression and micro-RNA based biomarkers has been studied in association with KD. The commonly used inflammatory markers e.g. erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and total leucocyte counts (TLC) lack specificity for KD. Proteomic studies are based on the identification of specific proteins in serum, plasma and urine by gel electrophoresis. A host of genetic studies have identified genes associated with KD and some of these genes can predict the course and coronary outcomes in the affected individuals. Most of these tests are in the early stages of their development and some of these can predict the course, propensity to develop coronary artery sequelae, intravenous immunoglobulin (IVIg) resistance and the severity of the illness in a patient. Development of clinical criteria based on these tests will improve our diagnostic acumen and aid in early identification and prevention of cardiovascular complications.

Variation in IL-21-secreting circulating follicular helper T cells in Kawasaki disease

Objective

Circulating follicular helper T (cTfh) cells are a specialized subset of CD4⁺ T cells that express the CXC-chemokine receptor 5 (CXCR5). These cells exhibit immune activities by inducing B cell differentiation and proliferation via the secretion of interleukin (IL)-21. Multiple studies have demonstrated that cTfh cells are associated with the progression and severity of numerous diseases. To investigate the role of cTfh cells in the development of Kawasaki disease (KD), we analyzed the distinct subpopulations of cTfh cells and serum IL-21 levels in different phases of KD.

Methods

According to the differential expression of inducible co-stimulator (ICOS) and programmed cell death protein 1 (PD-1), cTfh cells were divided into distinct subsets. We used flow cytometry and flow cytometric bead arrays (CBA) to analyze subsets of CD4⁺CXCR5⁺ T cells and serum IL-21 levels. The samples were collected from control subjects and Kawasaki disease patients in the acute and remission phases.

Results

In the acute phase (AP), the percentages of ICOS^highPD-1^high, ICOS⁺PD-1⁺, ICOS⁻PD-1⁺, CD45RA⁻IL-21⁺ cTfh cells and serum IL-21 levels significantly increased. Furthermore, the percentages of ICOS^highPD-1^high and ICOS⁺PD-1⁺ cTfh cells positively correlated with erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) values, whereas the percentage of ICOS⁻PD-1⁺ cTfh cells indicated negative correlations. The percentages of ICOS⁺PD-1⁺, ICOS^highPD-1^high and CD45RA⁻IL-21⁺ cTfh cells correlated positively with serum IL-21 levels. In the remission phase (RP), the percentages of ICOS⁻PD-1⁺, CD45RA⁻IL-21⁺ cTfh cells and serum IL-21 levels were significantly decreased. In contrast, the percentages of ICOS⁺PD-1⁺, ICOS^highPD-1^high, and ICOS⁺PD-1⁻ cTfh cells were further increased. Among these subsets, only CD45RA⁻IL-21⁺ cTfh cells correlated positively with serum IL-21 levels.

Conclusions

The present study is the first investigation that examined the distribution of circulating cTfh cell subsets in Kawasaki disease. Both cTfh cells and serum IL-21 are essential to the pathogenesis of KD. Our study provides further understanding of the immune response involved in KD and offers novel insights in the pathogenetic mechanism of this disease.

Electronic supplementary material

The online version of this article (10.1186/s12865-018-0282-8) contains supplementary material, which is available to authorized users.

The risk of hospitalization for respiratory tract infection (RTI) in children who are treated with high-dose IVIG in Kawasaki Disease: a nationwide population-based matched cohort study

Background

Kawasaki disease (KD) is an immune-mediated systemic vasculitis, and infection plays an important role in the pathophysiology of KD. The susceptibility to infectious disease in patients with KD remains largely unclear. This study aimed to investigate the risk of respiratory tract infection (RTI)-related hospitalizations in children with KD.

Methods

Data from the Taiwanese National Health Insurance Research Database was analyzed. We excluded patients with history of congenital abnormality, allergic diseases, or hospitalization history. Children with KD were selected as KD group and age- and sex-matched non-KD patients were selected as control group with 1:4 ratio. Both cohorts were tracked for one year to investigate the incidences of RTI-related hospitalizations. Cox regression hazard model was used to adjust for confounding factors and calculate the adjusted hazard ratio (aHR).

Results

Between January 1996 and December 2012, 4,973 patients with KD were identified as the KD group and 19,683 patients were enrolled as the control group. An obviously reduced risk of RTI-related hospitalizations was observed in KD patients (aHR: 0.75, 95% CI [0.66-0.85]). The decreased risk persisted through the first six-months follow-up period with a peak protection in 3-6 months (aHR: 0.49, 95% CI [0.37-0.64]).

Conclusions

KD patients had approximately half reduction of risk for RTI-related hospitalizations. The protective effects persisted for at least six months. Further studies are warranted to elucidate the entire mechanism and investigate the influences of intravenous immunoglobulin.

T-Helper Cytokine Profiles in Patients with Kawasaki Disease

Background and Objectives

Kawasaki disease is an acute systemic vasculitis of which pathogenesis suspected is caused by immune dysregulation. The goal of this study is to evaluate the activation pattern of T helper cell type 1 (Th1) and T helper cell type 2 (Th2) in patients with Kawasaki disease.

Subjects and Methods

Prospective study of 60 patients (male 36, female 24) with diagnosis of Kawasaki disease were enrolled. One hundred and eighty blood samples from these patients were collected according to the different clinical stages {before initial intravenous immunoglobulin (IVIG), 5 days after initial IVIG, 2 months after initial IVIG}. The plasma level of Th1 cytokines; interferon-gamma (IFN-γ) & interleukin (IL)-2 and Th2 cytokines; IL-4 & IL-10 were measured by enzyme-liked immunosorbent assay.

Results

In all patients, the plasma level of Th1 cytokines (IFN-γ, IL-2) and Th2 cytokines (IL-4 and IL-10) were markedly elevated during the acute stage of Kawasaki disease. Since then, the plasma level of all these cytokines decreased significantly along with the process of clinical stages. Regardless of the existence of coronary artery lesion or no response to initial IVIG treatment, there were no significant differences between them.

Conclusion

These data suggest that both Th1 and Th2 cells may be activated simultaneously during the acute stage of Kawasaki disease. Further studies are therefore required to establish the difference of activation pattern of T helper cells between Kawasaki disease and other inflammatory diseases.

Regulatory T cells in cardiovascular diseases

Inflammation is essential in the initial development and progression of many cardiovascular diseases involving innate and adaptive immune responses. The role of CD4(+)CD25(+)FOXP3(+) regulatory T (TREG) cells in the modulation of inflammation and immunity has received increasing attention. Given the important role of TREG cells in the induction and maintenance of immune homeostasis and tolerance, dysregulation in the generation or function of TREG cells can trigger abnormal immune responses and lead to pathology. A wealth of evidence from experimental and clinical studies has indicated that TREG cells might have an important role in protecting against cardiovascular disease, in particular atherosclerosis and abdominal aortic aneurysm. In this Review, we provide an overview of the roles of TREG cells in the pathogenesis of a number of cardiovascular diseases, including atherosclerosis, hypertension, ischaemic stroke, abdominal aortic aneurysm, Kawasaki disease, pulmonary arterial hypertension, myocardial infarction and remodelling, postischaemic neovascularization, myocarditis and dilated cardiomyopathy, and heart failure. Although the exact molecular mechanisms underlying the cardioprotective effects of TREG cells are still to be elucidated, targeted therapies with TREG cells might provide a promising and novel future approach to the prevention and treatment of cardiovascular diseases.

Plasma levels of monokine induced by interferon-gamma/chemokine (C-X-X motif) ligand 9, thymus and activation-regulated chemokine/chemokine (C-C motif) ligand 17 in children with Kawasaki disease

Background

Monokines induced by interferon-gamma/Chemokine (C-X-C motif) ligand 9 (MIG/CXCL9), thymus and activation-regulated chemokine/Chemokine (C-C motif) ligand 17 (TARC/CCL17) are chemotactic factors that specifically collect and activate leukocytes, which are considered as chemoattractants of T helper cells. In the present study, we have investigated the effects of T helper type-1 (Th1) cells and T helper type-2 (Th2) cells in Kawasaki disease (KD) by determining plasma levels of MIG/CXCL9 and TARC/CCL17 and exploring the relationship between MIG/CXCL9, TARC/CCL17 levels and coronary artery lesions (CAL).

Methods

Forty-three children patients with KD and 19 healthy controls were included in this study. General characteristics were obtained from all subjects. Plasma concentrations of chemotactic factors of MIG/CXCL9 and TARC/CCL17 were measured by enzyme-linked immunosorbent assay (ELISA) for all subjects.

Results

Plasma levels of MIG/CXCL9, TARC/CCL17, and the ratios of MIG/TARC were significantly elevated in pediatric patients with KD compared to those in the control group. There were also significantly higher levels of MIG/CXCL9, TARC/CCL17, MIG/TARC ratios and prominently lower hemoglobin (Hb) levels in KD with CAL compared to KD without coronary artery lesions (NCAL). Hb was significantly decreased and plasma MIG/CXCL9 levels had a significantly negative correlation with CRP in KD with CAL patients (KD-CAL), whereas a positive correlation of plasma MIG/CXCL 9 with WBC was observed in KD without CAL patients (KD-NCAL).

Conclusion

Th1 and Th2 cells may be involved in an imbalanced activation in pediatric KD patients during an acute period of the disease. Furthermore, immune lesions of vessels in KD patients may be mediated by the imbalanced activation of Th1 and Th2 cells.

Th17- and Treg-related cytokine and mRNA expression are associated with acute and resolving Kawasaki disease

BACKGROUND

Kawasaki disease is a vasculitis most commonly afflicting children <5 years of age. Many autoimmune diseases are associated with up-regulation of T helper (Th) 17 cells, and down-regulation Treg cells. Few studies have examined the Th17/Treg expression in Kawasaki disease.

METHODS

Blood samples were obtained from 186 children with Kawasaki disease at 24 h before IVIG therapy, followed by 3 days and 21 days after IVIG therapy. Thirty children with an acute febrile infectious disease and 30 healthy children were obtained as control. Plasma levels of Th17- and Treg-related cytokines including IL-6, IL-17A, IL-10, TGF-β, and mRNA expression levels of RORγt and Foxp3 were tested.

RESULTS

Patients with Kawasaki disease had higher levels of plasma IL-17A (25.35 ± 3.21 vs 7.78 ± 1.78 pg/ml, P < 0.001) and IL-6 (152.29 ± 21.94 vs 38.63 ± 12.40 pg/ml, P < 0.001) when compared to the febrile control group. IVIG resulted in a reduction in IL-6 and IL-17A at both 3 and 21 days after IVIG therapy. FoxP3 levels increased significantly 3 days after IVIG therapy (2.28 ± 0.34 vs 0.88 ± 0.14, P < 0.001). IVIG resistance was associated with higher levels of IL-10 and IL-17A.

CONCLUSION

Kawasaki disease was associated with higher IL-17A and IL-6, a cytokine profile similar to other autoimmune diseases. IVIG therapy resulted in increased expression of Treg-related FoxP3. IVIG resistance was associated with higher levels of IL-10 and IL-17A. Our findings provide further evidence that Kawasaki disease is an autoimmune-like disease.

Evaluation of intravenous immunoglobulin resistance and coronary artery lesions in relation to Th1/Th2 cytokine profiles in patients with Kawasaki disease

OBJECTIVE

To investigate the roles of serum Th1 and Th2 cytokines in Kawasaki disease (KD) and determine whether the Th1/Th2 cytokine profiles in children with KD may be involved in intravenous immunoglobulin (IVIG) resistance and development of coronary artery lesions (CALs).

METHODS

Serum Th1 and Th2 cytokines, including interferon-γ (IFNγ), tumor necrosis factor α (TNFα), interleukin-10 (IL-10), IL-6, IL-4, and IL-2, were measured using a cytometric bead array in the serum of 143 patients with KD before and after treatment with IVIG (pre-IVIG, at 3 days after temperature normalization following IVIG treatment [post-IVIG], and 1 month posttreatment).

RESULTS

Levels of IL-6, IL-10, TNFα, and IFNγ were significantly increased in KD patients pre-IVIG. Post-IVIG, the levels of IL-6, IL-10, and IFNγ quickly decreased. The levels of TNFα decreased significantly after IVIG treatment in KD patients without CALs post-IVIG and in KD patients who were IVIG responders, but increased slightly in KD patients with CALs post-IVIG and in KD patients who were IVIG nonresponders. Before IVIG treatment, the levels of IL-4, IL-6, IL-10, and IFNγ were significantly higher in KD patients with CALs than in those without CALs. The post-IVIG levels of IL-6 and IL-10 were significantly higher in IVIG nonresponders than in IVIG responders. Pre-IVIG, an IL-10 level >8 pg/ml had a sensitivity of 75.0% and a specificity of 64.4% for predicting CALs, while a TNFα level <2 pg/ml had a sensitivity of 66.7% and a specificity of 74.2% for predicting IVIG resistance. Post-IVIG, an IL-6 level >10 pg/ml had a sensitivity of 67.9% and a specificity of 81.7% for predicting CALs, while an IL-10 level >6 pg/ml had a sensitivity of 53.6% and a specificity of 86% for predicting CALs.

CONCLUSION

Determination of the serum Th1/Th2 cytokine profile may be helpful for predicting the disease prognosis and targeting treatment strategies in patients with KD.

Understanding the pathogenesis of Kawasaki disease by network and pathway analysis

Kawasaki disease (KD) is a complex disease, leading to the damage of multisystems. The pathogen that triggers this sophisticated disease is still unknown since it was first reported in 1967. To increase our knowledge on the effects of genes in KD, we extracted statistically significant genes so far associated with this mysterious illness from candidate gene studies and genome-wide association studies. These genes contributed to susceptibility to KD, coronary artery lesions, resistance to initial IVIG treatment, incomplete KD, and so on. Gene ontology category and pathways were analyzed for relationships among these statistically significant genes. These genes were represented in a variety of functional categories, including immune response, inflammatory response, and cellular calcium ion homeostasis. They were mainly enriched in the pathway of immune response. We further highlighted the compelling immune pathway of NF-AT signal and leukocyte interactions combined with another transcription factor NF- κ B in the pathogenesis of KD. STRING analysis, a network analysis focusing on protein interactions, validated close contact between these genes and implied the importance of this pathway. This data will contribute to understanding pathogenesis of KD.

Augmented TLR2 expression on monocytes in both human Kawasaki disease and a mouse model of coronary arteritis

BACKGROUND

Kawasaki disease (KD) of unknown immunopathogenesis is an acute febrile systemic vasculitis and the leading cause of acquired heart diseases in childhood. To search for a better strategy for the prevention and treatment of KD, this study compared and validated human KD immunopathogenesis in a mouse model of Lactobacillus casei cell wall extract (LCWE)-induced coronary arteritis.

METHODS

Recruited subjects fulfilled the criteria of KD and were admitted for intravenous gamma globulin (IVIG) treatment at the Kaohsiung Chang Gung Memorial Hospital from 2001 to 2009. Blood samples from KD patients were collected before and after IVIG treatment, and cardiovascular abnormalities were examined by transthoracic echocardiography. Wild-type male BALB/c mice (4-week-old) were intraperitoneally injected with LCWE (1 mg/mL) to induce coronary arteritis. The induced immune response in mice was examined on days 1, 3, 7, and 14 post injections, and histopathology studies were performed on days 7 and 14.

RESULTS

Both human KD patients and LCWE-treated mice developed coronary arteritis, myocarditis, valvulitis, and pericarditis, as well as elevated plasma levels of interleukin (IL)-2, IL-6, IL-10, monocyte chemoattractant protein (MCP)-1, and tumor necrosis factor (TNF)-α in acute phase. Most of these proinflammatory cytokines declined to normal levels in mice, whereas normal levels were achieved in patients only after IVIG treatment, with a few exceptions. Toll-like receptor (TLR)-2, but not TLR4 surface enhancement on circulating CD14+ monocytes, was augmented in KD patients before IVIG treatment and in LCWE-treated mice, which declined in patients after IVIG treatment.

CONCLUSION

This result suggests that that not only TLR2 augmentation on CD14+ monocytes might be an inflammatory marker for both human KD patients and LCWE-induced CAL mouse model but also this model is feasible for studying therapeutic strategies of coronary arteritis in human KD by modulating TLR2-mediated immune activation on CD14+ monocytes.

CD40 Gene polymorphisms associated with susceptibility and coronary artery lesions of Kawasaki disease in the Taiwanese population

BACKGROUND

Kawasaki disease (KD) is characterized by systemic vasculitis of unknown etiology. Our previous studies showed expression of CD40 ligand on CD4+ T cells correlated to the coronary artery lesion (CAL) and disease progress in KD. Other studies from Japan suggested the role of CD40L in the pathogenesis of CAL, and this might help explain the excessive number of males affected with KD but cannot be reproduced by Taiwanese population. This study was conducted to investigate the CD40 polymorphism in KD and CAL formation.

METHODS

A total of 950 subjects (381 KD patients and 569 controls) were investigated to identify 2 tagging single-nucleotide polymorphisms (tSNPs) of CD40 (rs4810485 and rs1535045) by using the TaqMan allelic discrimination assay.

RESULTS

A significant association was noted with regards to CD40 tSNPs (rs1535045) between controls and KD patients (P = 0.0405, dominant model). In KD patients, polymorphisms of CD40 (rs4810485) showed significant association with CAL formation (P = 0.0436, recessive model). Haplotype analysis did not yield more significant results between polymorphisms of CD40 and susceptibility/disease activity of KD.

CONCLUSIONS

This study showed for the first time that polymorphisms of CD40 are associated with susceptibility to KD and CAL formation, in the Taiwanese population.

Hospitalisation with infection, asthma and allergy in Kawasaki disease patients and their families: genealogical analysis using linked population data

BACKGROUND

Kawasaki disease results from an abnormal immunological response to one or more infectious triggers. We hypothesised that heritable differences in immune responses in Kawasaki disease-affected children and their families would result in different epidemiological patterns of other immune-related conditions. We investigated whether hospitalisation for infection and asthma/allergy were different in Kawasaki disease-affected children and their relatives.

METHODS/MAJOR FINDINGS

We used Western Australian population-linked health data from live births (1970-2006) to compare patterns of hospital admissions in Kawasaki disease cases, age- and sex-matched controls, and their relatives. There were 295 Kawasaki disease cases and 598 age- and sex-matched controls, with 1,636 and 3,780 relatives, respectively. Compared to controls, cases were more likely to have been admitted at least once with an infection (cases, 150 admissions (50.8%) vs controls, 210 admissions (35.1%); odds ratio (OR) = 1.9, 95% confidence interval (CI) 1.4-2.6, P = 7.2×10⁻⁶), and with asthma/allergy (cases, 49 admissions (16.6%) vs controls, 42 admissions (7.0%); OR = 2.6, 95% CI 1.7-4.2, P = 1.3×10⁻⁵). Cases also had more admissions per person with infection (cases, median 2 admissions, 95% CI 1-5, vs controls, median 1 admission, 95% CI 1-4, P = 1.09×10⁻⁵). The risk of admission with infection was higher in the first degree relatives of Kawasaki disease cases compared to those of controls, but the differences were not significant.

CONCLUSION

Differences in the immune phenotype of children who develop Kawasaki disease may influence the severity of other immune-related conditions, with some similar patterns observed in relatives. These data suggest the influence of shared heritable factors in these families.

Transforming growth factor-beta signaling pathway in patients with Kawasaki disease

BACKGROUND

Transforming growth factor (TGF)-β is a multifunctional peptide that is important in T-cell activation and cardiovascular remodeling, both of which are important features of Kawasaki disease (KD). We postulated that variation in TGF-β signaling might be important in KD susceptibility and disease outcome.

METHODS AND RESULTS

We investigated genetic variation in 15 genes belonging to the TGF-β pathway in a total of 771 KD subjects of mainly European descent from the United States, the United Kingdom, Australia, and the Netherlands. We analyzed transcript abundance patterns using microarray and reverse transcriptase-polymerase chain reaction for these same genes, and measured TGF-β2 protein levels in plasma. Genetic variants in TGFB2, TGFBR2, and SMAD3 and their haplotypes were consistently and reproducibly associated with KD susceptibility, coronary artery aneurysm formation, aortic root dilatation, and intravenous immunoglobulin treatment response in different cohorts. A SMAD3 haplotype associated with KD susceptibility replicated in 2 independent cohorts and an intronic single nucleotide polymorphism in a separate haplotype block was also strongly associated (A/G, rs4776338) (P=0.000022; odds ratio, 1.50; 95% confidence interval, 1.25 to 1.81). Pathway analysis using all 15 genes further confirmed the importance of the TGF-β pathway in KD pathogenesis. Whole-blood transcript abundance for these genes and TGF-β2 plasma protein levels changed dynamically over the course of the illness.

CONCLUSIONS

These studies suggest that genetic variation in the TGF-β pathway influences KD susceptibility, disease outcome, and response to therapy, and that aortic root and coronary artery Z scores can be used for phenotype/genotype analyses. Analysis of transcript abundance and protein levels further support the importance of this pathway in KD pathogenesis.

Marker of T-cell activation is elevated in refractory Kawasaki disease

BACKGROUND

The aim of this study was to investigate whether T-cell activation is involved in the pathogenesis of Kawasaki disease (KD) resistant to intravenous immunoglobulin (IVIG) treatment.

METHODS

Serum samples were obtained from 27 patients who fulfilled the diagnostic criteria for KD. These 27 patients were divided into three groups according to their responses to IVIG: Group A, nine patients who showed no response to either initial IVIG or additional IVIG; Group B, six patients who did not respond to initial IVIG but did respond to additional IVIG; Group C, 12 patients who responded to initial IVIG. Serum samples were obtained before and after initial IVIG. Using a commercial chemiluminescence enzyme immunoassay, we examined the serum levels of two cytokines related to T-cell activation and the severity of inflammation: soluble interleukin-2 receptor and interleukin-6.

RESULTS

There were no significant differences in the serum levels of the two cytokines before initial IVIG among the three groups, but significant intergroup differences were evident after initial IVIG in the serum levels of soluble interleukin-2 receptor (P < 0.01, Group A > C) and interleukin-6 (P < 0.01, Group A > B > C).

CONCLUSIONS

Our results show that marker of T-cell activation is elevated most markedly in KD patients resistant to both initial and additional IVIG, and suggest that T cells may be activated in refractory KD.

BTNL2 gene polymorphisms may be associated with susceptibility to Kawasaki disease and formation of coronary artery lesions in Taiwanese children

The butyrophilin-like 2 (BTNL2) gene is a member of the B7 receptor family that probably functions as a T cell costimulatory molecule. Because altered T cell functions are implicated in dysregulation of the immune response seen in Kawasaki disease (KD), it is reasonable to speculate that BTNL2 gene is involved in the pathophysiology of KD. The purpose of this study was to investigate whether polymorphisms of the BTNL2 gene are associated with KD and the development of coronary artery lesions (CALs) in Taiwanese children. Nine-three patients with KD and 669 ethnically matched healthy controls were genotyped for BTNL2 gene rs1555115 C/G and rs2395158 A/G polymorphisms. The frequency of GG genotype of rs 1555115 was significantly higher in KD patients compared with controls (2.2% vs 0.2%, P = 0.012). The odds ratio for developing KD in individuals with rs 1555115 GG genotype was 14.7 (95% confidence interval, 2.04-105.5, P = 0.003) compared with individuals with rs 1555115 CG and CC genotypes. No significant difference was observed in the genotype and allelic frequencies of rs 2395158 polymorphism between KD patients and controls. However, the frequency of the G allele of rs 2395158 was significantly higher in KD patients with CALs than in those without CALs (P = 0.001). No significant difference was observed in the genotype and allelic frequencies of rs 1555115 polymorphism between KD patients with and without CALs. In conclusion, our results suggest that BTNL2 gene polymorphisms might be genetic markers of KD susceptibility and risk of coronary artery complication in Taiwanese children.

Unique activation status of peripheral blood mononuclear cells at acute phase of Kawasaki disease

Although Kawasaki disease (KD) is characterized by a marked activation of the immune system with elevations of serum proinflammatory cytokines and chemokines at acute phase, the major sources for these chemical mediators remain controversial. We analysed the activation status of peripheral blood mononuclear cells (PBMCs) by flow cytometry, DNA microarray and quantitative reverse transcription-polymerase chain reaction. The proportions of CD69+ cells in both natural killer cells and gammadeltaT cells at acute-phase KD were significantly higher than those at convalescent-phase KD. Microarray analysis revealed that five genes such as NAIP, IPAF, S100A9, FCGR1A and GCA up-regulated in acute-phase KD and the pathways involved in acute phase KD were related closely to the innate immune system. The relative expression levels of damage-associated molecular pattern molecule (DAMP) (S100A9 and S100A12) genes in PBMCs at acute-phase KD were significantly higher than those at convalescent-phase KD, while those of TNFA, IL1B and IL6 genes were not significantly different between KD patients and healthy controls. Intracellular production of tumour necrosis factor-alpha, interleukin-10 and interferon-gamma in PBMCs was not observed in KD patients. The present data have indicated that PBMCs showed a unique activation status with high expression of DAMP genes but low expression of proinflammatory cytokine genes, and that the innate immune system appears to play a role in the pathogenesis and pathophysiology of KD.

A clinical grade poly I:C-analogue (Ampligen) promotes optimal DC maturation and Th1-type T cell responses of healthy donors and cancer patients in vitro

Maturation of dendritic cells (DC) can be triggered in vitro by inflammatory cytokines or Toll-like receptor (TLR) ligands such as CpG or polyI:C. Corresponding, well-characterized agents which can be applied in clinical settings are sparse. We have evaluated a clinical grade, non-toxic analogue of polyI:C, poly(I:C12U) (Ampligen), as a potential adjuvant for cancer immunotherapy, for its ability to drive maturation of human myeloid DC. Our results provide evidence that poly(I:C12U) is effective in inducing optimal phenotypic (elevated levels of MHC-Class I/Class II, CD83, CCR7, CD86 and CD40 molecules) and functional maturation of human DC in vitro, capable of promoting the production of the inflammatory (Th1-type) cytokine IL-12, with significantly lower levels of IL-10 production, compared to that induced by the parent compound polyI:C. Importantly, poly(I:C12U) has a comparable effect on the maturation and function of DC derived either from healthy donors or cancer patients indicating that it is able to overcome any immune suppressive factors associated with the tumour bearing state. These characteristics make poly(I:C12U) a suitable agent for use as an adjuvant in cancer directed immunotherapeutic regimes.

Kawasaki disease

PURPOSE OF REVIEW

Kawasaki disease is still a dilemma for pediatricians, especially its atypical or incomplete presentation. The current diagnostic criteria appear inadequate, and the early diagnosis frequently remains challenging with high risk of coronary damage. This review focuses on recent data concerning Kawasaki disease etiology and pathogenesis, and emphasizes the proposal of including altered laboratory values in revised diagnostic criteria aimed at identifying patients with incomplete disease.

RECENT FINDINGS

Despite a timely treatment, approximately 15% of children have persistent or recurrent fever, thus requiring additional intravenous immunoglobulin, corticosteroids, immunosuppressant, and eventually biologic drugs. Recent cardiologic tests strongly suggest that endothelial damage may lead to coronary stenosis and myocardial ischemia over time, even in children apparently normal at initial cardiac evaluation. New noninvasive tools are suggested to monitor coronary artery aneurysm outcome. Giant coronary artery aneurysms still represent a severe life-threatening complication. There is as yet no agreement regarding the prevention of thrombosis and stenosis in children with giant aneurysms.

SUMMARY

Due to earlier recognition, aggressive medical treatment, and surgical procedures, the quality of life in patients with Kawasaki disease is significantly improved. The identification of children at high risk for coronary artery aneurysms is crucial in order to reduce the occurrence of sudden death in adolescence and early adulthood. High parameters of inflammation, anemia, and low sodium and albumin levels, along with persistent unexplained fever, should alert clinicians to suspect the disease even though all clinical symptoms are lacking.

Kawasaki disease: infection, immunity and genetics

Kawasaki disease is an acute multisystem vasculitic syndrome of unknown etiology occurring mostly in infants and children younger than 5 years of age. In developed countries, Kawasaki disease is currently the leading cause of acquired heart diseases in children. However, it is still a mysterious disease. In this article, we reviewed and summarized from the aspects based on infection agents, host immune dysregulation and genetic background intended to establish a feasible infection-immunogenetic pathogenesis for this mysterious disease and also provided the rational strategy to explore optimal treatment of this disease.

Pathogénie des vascularites systémiques primitives (II): vascularites ANCA-négatives

The pathogenesis of different types of systemic vasculitis negative for antineutrophil cytoplasm antibodies (ANCA) and involving small or medium-sized vessels is not very well documented. During polyarteritis nodosa (PAN), which is related to hepatitis B virus (HBV) infection, as well as during cryoglobulinemic vasculitides, associated with hepatitis C virus (HCV), and probably during Henoch Schönlein purpura, histological lesions may result from the deposition of immune complexes formed from viral antigens and from antibodies responsible for the activation of the classic complement pathway and for recruitment of polymorphonuclear neutrophils. Two other mechanisms are discussed for other types of ANCA-negative systemic vasculitis: immune complex deposition and sheer stress at arterial bifurcation points. A bacterial superantigen is suspected in Kawasaki disease but remains unproved.

Personalized exposure assessment: promising approaches for human environmental health research

New technologies and methods for assessing human exposure to chemicals, dietary and lifestyle factors, infectious agents, and other stressors provide an opportunity to extend the range of human health investigations and advance our understanding of the relationship between environmental exposure and disease. An ad hoc Committee on Environmental Exposure Technology Development was convened to identify new technologies and methods for deriving personalized exposure measurements for application to environmental health studies. The committee identified a "toolbox" of methods for measuring external (environmental) and internal (biologic) exposure and assessing human behaviors that influence the likelihood of exposure to environmental agents. The methods use environmental sensors, geographic information systems, biologic sensors, toxicogenomics, and body burden (biologic) measurements. We discuss each of the methods in relation to current use in human health research; specific gaps in the development, validation, and application of the methods are highlighted. We also present a conceptual framework for moving these technologies into use and acceptance by the scientific community. The framework focuses on understanding complex human diseases using an integrated approach to exposure assessment to define particular exposure-disease relationships and the interaction of genetic and environmental factors in disease occurrence. Improved methods for exposure assessment will result in better means of monitoring and targeting intervention and prevention programs.

Altered T helper 1 reaction but not increase of virus load in patients with dengue hemorrhagic fever

To investigate whether dengue-2 patients with and without dengue hemorrhagic fever had different virus load, immune mediators, or T helper (Th) reaction, we simultaneously measured virus load, immune mediators and the Th1/Th2 transcription factors T-bet/GATA-3 mRNA expression in a large outbreak of dengue-2 infections in Southern Taiwan. Results showed that virus load was not significantly different between patients with and without dengue hemorrhagic fever. Patients with dengue fever had higher IFN-gamma levels, but patients with dengue hemorrhagic fever had significantly higher IL-10 levels. Further studies showed that patients with dengue hemorrhagic fever had a significantly lower T-bet than those with dengue fever, but GATA-3 mRNA expression in peripheral blood leukocytes was not significant difference between both groups. In conclusion, altered Th1 reaction as reflected by lower T-bet mRNA expression associated with higher IL-10 levels might be involved in the pathogenesis of dengue hemorrhagic fever.