Immunological abnormalities in Kawasaki disease with coronary artery lesions

Tight junction protein ZO-1 in Kawasaki disease

Background

Kawasaki disease (KD) is a form of systemic febrile vasculitis that is complicated with coronary artery lesions (CAL). The tight junctions that maintain the intestinal barrier also play a role in systemic inflammatory diseases. Serum zonula occludens-1 (ZO-1) expression was found to be significantly lower in asthmatic patients, and another study reported that elevated systemic ZO-1 was positively correlated with inflammation in cirrhotic patients. A murine model of KD vasculitis demonstrated that vasculitis depended on intestinal barrier dysfunction, which is maintained by tight junctions. In this study, we aimed to investigate the role of the tight junction zonula occludens-1 (ZO-1) in the treatment response of intravenous immunoglobulin (IVIG) and the occurrence of CAL formation in KD patients.

Methods

We enrolled 40 KD patients, 12 healthy controls, and 12 febrile controls in this study. The serum levels of tight junction ZO-1 were determined by enzyme-linked immunosorbent assay.

Results

The serum ZO-1 level was higher in the fever control group but did not reach a statistical significance. KD patients who received a second dose of IVIG treatment due to initial IVIG unresponsiveness had a higher serum levels of tight junction ZO-1, but without statistical significance (2.15 ± 0.18 vs. 2.69 ± 0.31 ng/mL, p = 0.058). KD patients who developed a CAL demonstrated a significant lower serum tight junction ZO-1 levels than KD without CAL formation (1.89 ± 0.16 vs. 2.39 ± 0.15 ng/mL, p = 0.027). After multiple logistic regression analysis, ZO-1 levels [(95% confidence interval (CI): 0.058 ~ 0.941, odds ratio (OR) = 0.235, p = 0.041)] showed as the risk factor for CAL formation.

Conclusion

Serum levels of tight junction ZO-1 levels were lower in KD patients than fever controls and associated with CAL formation.

Refractory Kawasaki Disease Presenting With Erythema at Bacille Calmette-Guérin Inoculation Site: A Paediatric Case Report

Kawasaki disease (KD) is an autoimmune disease that generally affects children under the age of five years. It has a variety of clinical manifestations which may be either specific or nonspecific. Intravenous immunoglobulin and aspirin are the mainstays of treatment. There are unusual circumstances where patients are resistant to conventional treatment. We report a one-year-old girl who presented with a 12-day history of fever in association with erythema at the site of Bacille Calmette-Guérin (BCG) scar. She did not respond successfully to conventional treatment although she was diagnosed to have Kawasaki disease. Eventually, she responded to intravenous methylprednisolone and was diagnosed as having refractory Kawasaki disease.

The human blood DNA methylome identifies crucial role of β-catenin in the pathogenesis of Kawasaki disease

Kawasaki disease (KD) is a type of acute febrile vasculitis syndrome and is the most frequent cause of cardiac illness in children under the age of five years old. Although the etiology of KD remains largely unknown, some recent genome-wide studies have indicated that epigenetic factors may be important in its pathogenesis. We enrolled 24 KD patients and 24 non-KD controls in this study to access their DNA methylation status using HumanMethylation450 BeadChips. Another 34 KD patients and 62 control subjects were enrolled for expression validation. Of the 3193 CpG methylation regions with a methylation difference ≥ 20% between KD and controls, 3096 CpG loci revealed hypomehtylation, with only 3% being hypermethylated. Pathway buildup identified 11 networked genes among the hypermethylated regions, including four transcription factors: nuclear factor of activated T-cells 1, v-ets avian erythroblastosis virus E26 oncogene homolog 1, runt related transcription factor 3, and retinoic acid receptor gamma, as well as the activator β-catenin. Ten of these network-selected genes demonstrated a significant decrease in mRNA in KD patients, whereas only CTNNB1 significantly decreased in correlation with coronary artery lesions in KD patients. Furthermore, CTNNB1-silenced THP-1 monocytic cells drastically increased the expression of CD40 and significantly increased the expression of both CD40 and CD40L in cocultured human coronary artery endothelial cells. This study is the first to identify network-based susceptible genes of hypermethylated CpG loci, their expression levels, and the functional impact of β-catenin, which may be involved in both the cause and the development of KD.

Clinical characteristics of Kawasaki disease with sterile pyuria

Purpose

Kawasaki disease (KD) is a systemic vasculitis and affects many organ systems. It often presents sterile pyuria, microscopic hematuria, and proteinuria due to renal involvement. The aims of this study were to define clinical characteristics of acute KD patients with pyuria and to analyze meaning of pyuria in KD.

Methods

The medical records and laboratory findings including serum and urine test of 133 patients with KD admitted to Yeungnam University Hospital from March 2006 to December 2010 were reviewed retrospectively.

Results

Forty patients had sterile pyuria and their clinical characteristics including age, gender and body weight were not significantly different with those who did not have pyuria. Fever duration after treatment was significantly longer in KD patients with pyuria. Erythrocyte sedimentation rate, C-reactive protein and serum concentration of alanine aminotransferase were significantly higher in patients with pyuria. Hyponatremia and coronary artery lesion were seen more often in patients with pyuria but there was no significant difference. Also serum blood urea nitrogen was significantly higher in KD patients with pyuria. Urine β₂-microglobulin was elevated in both patients groups and showed no difference between two groups.

Conclusion

We found more severe inflammatory reaction in KD patients with pyuria. We also found elevation of some useful parameters like β₂-microglobulin that indicate renal involvement of KD through the urine test. Careful management and follow up will need for KD patients with pyuria and it is necessary in the future to study the specific parameters for renal involvement of KD.

Alteration of CD4CD25Foxp3 T cell level in Kawasaki disease

PURPOSE

Exaggerated pro-inflammatory reactions during the acute phase of Kawasaki disease (KD) suggest the role of immune dysregulation in the pathogenesis of KD. We investigated the profiles of T regulatory cells and their correlation with the clinical course of KD.

METHODS

Peripheral blood mononuclear cells were collected from 17 KD patients during acute febrile and subacute afebrile phases. T cells expressing CD4, CD25, and Foxp3 were analyzed using flow cytometry, and the results were correlated with the clinical course of KD.

RESULTS

The percentage of circulating CD4(+)CD25(high)Foxp3(+) T cells among CD4(+) T cells was significantly higher during the subacute afebrile phase than during the acute febrile phase (1.10%±1.22% vs. 0.55%±0.53%, P=0.049). Although levels of CD4(+)CD25(low)Foxp3(+) T cells and CD4(+)CD25(-)Foxp3(+) T cells were only slightly altered, the percentage of CD4(+)CD25(+)Foxp3(-) T cells among CD4(+) T cells was significantly lower during the subacute afebrile phase than during the acute febrile phase (2.96%±1.95% vs. 5.64%±5.69%, P=0.036). Consequently, the ratio of CD25(high)Foxp3(+) T cells to CD25(+)Foxp3(-) T cells was higher during the subacute afebrile phase than during the acute febrile phase (0.45%±0.57% vs. 0.13%±0.13%, P=0.038).

CONCLUSION

Decreased CD4(+)CD25(high)Foxp3(+) T cells and/or an imbalanced ratio of CD4(+)CD25(high)Foxp3(+) T cells to CD4(+)CD25(+)Foxp3(-) T cells might play a role in KD development. Considering that all KD patients were treated with intravenous immunoglobulin (IVIG), recovery of CD4(+)CD25(high)Foxp3(+) T cells during the subacute afebrile phase could be a mechanism of IVIG.

A genome-wide association study identifies novel and functionally related susceptibility Loci for Kawasaki disease

Kawasaki disease (KD) is a pediatric vasculitis that damages the coronary arteries in 25% of untreated and approximately 5% of treated children. Epidemiologic data suggest that KD is triggered by unidentified infection(s) in genetically susceptible children. To investigate genetic determinants of KD susceptibility, we performed a genome-wide association study (GWAS) in 119 Caucasian KD cases and 135 matched controls with stringent correction for possible admixture, followed by replication in an independent cohort and subsequent fine-mapping, for a total of 893 KD cases plus population and family controls. Significant associations of 40 SNPs and six haplotypes, identifying 31 genes, were replicated in an independent cohort of 583 predominantly Caucasian KD families, with NAALADL2 (rs17531088, p(combined) = 1.13 x 10(-6)) and ZFHX3 (rs7199343, p(combined) = 2.37 x 10(-6)) most significantly associated. Sixteen associated variants with a minor allele frequency of >0.05 that lay within or close to known genes were fine-mapped with HapMap tagging SNPs in 781 KD cases, including 590 from the discovery and replication stages. Original or tagging SNPs in eight of these genes replicated the original findings, with seven genes having further significant markers in adjacent regions. In four genes (ZFHX3, NAALADL2, PPP1R14C, and TCP1), the neighboring markers were more significantly associated than the originally associated variants. Investigation of functional relationships between the eight fine-mapped genes using Ingenuity Pathway Analysis identified a single functional network (p = 10(-13)) containing five fine-mapped genes-LNX1, CAMK2D, ZFHX3, CSMD1, and TCP1-with functional relationships potentially related to inflammation, apoptosis, and cardiovascular pathology. Pair-wise blood transcript levels were measured during acute and convalescent KD for all fine-mapped genes, revealing a consistent trend of significantly reduced transcript levels prior to treatment. This is one of the first GWAS in an infectious disease. We have identified novel, plausible, and functionally related variants associated with KD susceptibility that may also be relevant to other cardiovascular diseases.

Kawasaki syndrome in the ED

In a retrospective case review of inpatient and emergency department (ED) records during a 55-month period, 155 hospitalizations for Kawasaki syndrome (KS) were identified, of which 44 were seen in the ED. In 16 cases, KS was already suspected by their private physicians and confirmed in the ED by a KS specialist. In the remaining 28, patients presented initially to the ED. In 18 of these 28 (64%), KS was identified or suspected in the ED. In the other 10, the diagnosis was delayed. In four instances, patients were hospitalized for other reasons. In all cases in which the diagnosis of KS was not made in the ED, viral infections or sepsis were suspected. One child presented to the ED in respiratory arrest and severe bradycardia.