Reduced frequencies of peripheral interferon-gamma-producing CD4+ and CD4- cells during acute Kawasaki disease

Atlas of circulating immune cells in Kawasaki disease

Increasing evidence shows that the pathogenesis of Kawasaki disease (KD) is caused by abnormal and unbalanced innate and adaptive immune responses. However, the changes in and functions of adaptive immune cells in the peripheral blood of subjects with KD remain controversial. In this study, three different methods, CIBERSORT, Immune Cell Abundance Identifier (ImmuCellAI), and immune cell markers, were used to evaluate the proportions and abundances of immune cells in eight KD datasets (GSE9863, GSE9864, GSE18606, GSE63881, GSE68004, GSE73461, GSE73463, and GSE64486; a total of 1,251 samples). Compared with those in normal controls and convalescent KD samples, the proportions and abundances of innate immune cells such as neutrophils, monocytes, and macrophages in acute KD peripheral blood samples were significantly increased, while those of adaptive immune cells such as B and T cells were significantly decreased. The change tendencies of these immune cells were similar to those observed in other febrile illnesses but were more significant. However, in the coronary artery tissues of patients with convalescent KD, adaptive immune cells, especially B cells and CD8+ T cell subsets, were significantly increased. This result suggests that adaptive immune cells can be selectively recruited from peripheral blood into the coronary arteries. In addition, we found that elevated neutrophils in peripheral blood could be used as a biomarker to assist in the differential diagnosis of KD, but we did not find immune cells that could accurately predict intravenousimmunoglobulin (IVIG) responses in multiple datasets.

Distribution of distinct subsets of circulating T follicular helper cells in Kawasaki disease

Background

Kawasaki disease (KD) is an acute febrile vasculitis that primarily affects children. Previous studies have shown that both innate and adapt immune systems are involved in the immunopathogenesis of KD. The following study analyzes the distribution of the subsets of Circulating T follicular helper cells (cTfh cells) in KD patients with and without coronary artery lesions (CALs).

Methods

Twenty KD patients and fifteen healthy sex- and age- matched children were enrolled. Patients were divided into two groups depending on CALs. Blood samples were collected respectively before and after intravenous immunoglobulin (IVIG) administration. Circulating Tfh cells were categorized into three subsets by flow cytometry including cTfh1 (CXCR3 + CCR6-), cTfh2 (CXCR3-CCX6-) and cTfh17 (CXCR3-CCR6+) cells in circulating CD3 + CD4 + CXCR5 + CD45RA- T cells. Cytometric bead arrays were used to analyze the level of IFN-γ, IL-4 and IL-17A.

Results

We found that frequency of cTfh2 cells was significantly elevated in KD patients before IVIG administration with low expression of cTfh1 cells, where the ratio of cTfh2 + cTfh17/cTfh1 significantly increased. Levels of IFN-γ, IL-4 and IL-17A in KD were significantly higher compared to controls. Further analysis showed that cTfh1 cells were negatively correlated with serum CRP, whereas cTfh2 cells were positively correlated with serum CRP and ESR. Comparison of different groups showed that frequency of cTfh1 cells in CALs+ group were significantly lower compared to CALs- group. In contrast, cTfh2 cells in CALs+ group significantly increased. After IVIG administration, frequency of cTfh2 cells and the ratio significantly decreased while the frequency of cTfh1 cells significantly increased. Meanwhile, all levels of cytokines decreased.

Conclusions

Our data demonstrated that cTfh1 and cTfh2 cells participate in the pathogenesis of KD, and that the two subsets might be associated with CALs.

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.

Increased risk of Kawasaki disease in children with common allergic diseases

PURPOSE

Growing evidence reveals a link between Kawasaki disease (KD) and allergic diseases. This population-based case-control study is to investigate the onset of allergic diseases in children and the associated risks of KD.

METHODS

From 1996 to 2008, 2748 children with KD and 10,656 randomly selected controls were enrolled. Odds ratios of KD were calculated for the association with pre-existing allergic diseases.

RESULTS

The children with a single allergic disease had an increased risk of KD, with adjusted odds ratios of having KD of 1.82 for urticaria (95% confidence interval [CI], 1.54-2.14), 1.44 for allergic rhinitis (95% CI, 1.23-1.70), and 1.22 for atopic dermatitis (95% CI, 1.06-1.39). The adjusted odds ratios increased with the number of concurrent allergic diseases, from 1.61 (95% CI, 1.43-1.82) for those with only one allergic disease to 1.71 (95% CI, 1.48-1.98) for those with at least two allergic diseases. The children who made two or more medical visits for associated allergic diseases per year had an increased risk of KD.

CONCLUSIONS

Children with onset of allergic diseases were at increased risk for KD, and the increased risk was associated with the cumulative effect of concurrent allergic diseases and frequency of seeking medical care.

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.

Levels of intra- and extracellular heat shock protein 60 in Kawasaki disease patients treated with intravenous immunoglobulin

Immune reactivity to autologous heat shock protein 60 (HSP60) has been reported to be associated with a favorable prognosis in autoimmune diseases. To provide a clue for the possible role of HSP60 in Kawasaki disease (KD), we investigated the levels of intra- and extracellular HSP60 in the course of KD. In KD patients, autologous HSP60 was abundantly expressed in CD11c(+) cells during the acute phase and subsequently decreased during the subacute phase. Most of HSP60-expressing CD11c(+) cells observed in the acute phase was composed of CD11c(low) cells instead of CD11c(high) cells, which were dominant in the subacute phase. In contrast, circulating HSP60 levels were higher in the subacute phase than those in the acute phase, reflecting higher level of HSP60 exposure to the immune system of patients during recovery. These changes in the levels of intra- and extracellular HSP60 were not observed in patients with other febrile diseases. The observed features of HSP60 expression in patients with KD are in favor of a role for autologous HSP60 as a regulator for control of inflammation, rather than a proinflammatory mediator in KD.

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

To clarify the functional state of T cells in Kawasaki disease, we analysed mRNA expression levels of Th1/Th2 cytokines (IFN-gamma and IL-4) along with Th1/Th2-inducing transcription factors, T-bet and GATA-3, which play pivotal roles in the development of Th1 and Th2 cells, respectively. By real-time PCR, IFN-gamma mRNA levels in peripheral blood mononuclear cells (PBMNC) were significantly decreased in Kawasaki disease patients compared with those with measles, and tended to be lower than those in healthy controls. T-bet mRNA levels were significantly decreased in patients with Kawasaki disease compared with healthy controls. In addition, IL-4 and GATA-3 mRNA levels were significantly decreased in Kawasaki disease compared with healthy controls. Regulatory cytokine mRNA levels (TGF-beta and IL-10) were also decreased in Kawasaki disease. The mRNA levels of IFN-gamma showed a significant positive correlation with those of T-bet in Kawasaki disease. These results suggest that the suppressed function of Th1 and Th2, associated with the suppression of both T-bet and GATA-3 gene expression, may be one of the immunological characteristics of Kawasaki disease.

Serum levels of interleukin-18 are elevated in the subacute phase of kawasaki syndrome

BACKGROUND

Elevations of various cytokines, including Th1 and Th2 cytokines, have been reported in the acute phase of Kawasaki syndrome (KS). As interleukin (IL)-18 plays an important role in the Th1 cell response, investigating the relevance of IL-18 in KS should be helpful in determining the pathophysiology of KS. Therefore, we examined the IL-18 values in KS.

METHODS

Serum IL-18 values were measured by an enzyme-linked immunosorbent assay. Samples were obtained from 41 patients in the acute and subacute phase of KS, 35 age-matched febrile controls and 13 afebrile controls.

RESULTS

No difference was observed in the values of white blood cell counts or C-reactive protein between acute-phase KS patients and febrile controls. On the contrary, acute-phase KS patients showed a significantly lower mean IL-18 value (398 +/- 206 pg/ml) than that of febrile controls (584 +/- 307 pg/ml) (p = 0.006). Subacute-phase KS patients showed a significantly elevated level of IL-18 (517 +/- 276 pg/ml) compared to acute-phase patients (p = 0.0008). The IL-18 values in the subacute-phase patients showed a significant positive correlation with the duration of fever (r = 0.427, p = 0.0055) and also with the presence of coronary artery abnormalities (r = 0.332, p = 0.0340). The incidence of elevated IL-18 values in the subacute-phase patients was significantly higher than that in the afebrile controls (p = 0.048).

CONCLUSIONS

Patients with KS showed normal IL-18 values in the acute phase and elevated values in the subacute phase. IL-18 pathways were activated in the subacute phase of KS, and subacute IL-18 values might be reflected in the severity of KS.

Could a herpesvirus be the cause of Kawasaki disease?

Kawasaki disease (KD) is an acute vasculitis of early childhood, the cause of which remains unknown. Many lines of evidence suggest an infectious aetiology, which may-in association with host genetic factors-lead to the characteristic clinical presentation of this disease. Accumulating data including animal models and epidemiological and immunological studies, suggest that viruses have an important role in human vasculitic disease. Whereas many infectious agents including viruses have been postulated as possible causes of KD, no single agent has been shown definitely to be associated with this disease and the causative agent remains elusive. We hypothesise that a ubiquitous virus of the gamma herpesvirus family is the likely aetiological agent for KD in genetically susceptible individuals.