Susceptibility Loci to Coronary Arteritis in Animal Model of Kawasaki Disease Induced withCandida albicans-Derived Substances

Recognition of alpha-mannan by dectin 2 is essential for onset of Kawasaki disease-like murine vasculitis induced by Candida albicans cell-wall polysaccharide

Objectives: Using a murine model of systemic Kawasaki disease (KD)-like vasculitis induced by Candida albicans cell-wall-derived mannan · β-glucan · protein complexes, the objective was to elucidate the relationships of β-glucan receptor dectin-1 (D1) and α-mannan receptor dectin-2 (D2) to the onset of that vasculitis.Methods: The incidence and histological severity of vasculitis were compared among mice lacking the genes for D1 or D2 (i.e. D1^-/- and D2^-/-) and wild-type (WT) mice.Results: The incidences of vasculitis in the three animal groups were 100% (18/18) in the WT group, 100% (18/18) in the D1^-/- group, and 0% (0/18) in the D2^-/- group. In the WT and D1^-/- mice, severe inflammatory cell infiltration, consisting mainly of neutrophils and macrophages, was seen in the aortic root and the coronary arteries. On the other hand, in the D2^-/- mice, not even mild vascular lesions such as endoarteritis were seen.Conclusion: Recognition of α-mannan by D2 played an important role in the onset of vasculitis in the studied murine model.

Melatonin: A hypothesis for Kawasaki disease treatment

Kawasaki disease (KD) is the most common cause of acquired heart disease with unknown etiology among children in developed countries. Acute inflammation of the vasculature, genetic susceptibility and immunopathogenesis based on a transmittable and infectious origin, are the pathologic events involved in the early inflammatory etiology and progression of this disease. However, the exact causes of KD remain unknown. Current proposed recommendations include three therapy lines; firstly, an initial standard therapy with intravenous immunoglobulin (IVIG) followed by aspirin. Secondly, in cases of high risk of coronary lesions, the adjunctive therapy with corticosteroid is commonly considered. Thirdly, in KD patients refractory to the previous therapies, tumor necrosis factor (TNF-α) antagonists are being used to modulate pro-inflammatory cytokines. In view of this status quo, our starting hypothesis is that the ubiquitous and non-toxic neurohormone melatonin could be of critical importance in developing novel adjuvant therapies against KD, as it occurs with a plethora of other diseases. Considering its pleiotropic properties, particularly its antiinflammatory and immunoregulatory capacities, melatonin should be of great therapeutic interest for helping to control the main pathologic features of KD patients. In addition, this multifunctional indole has a safe pharmacological profile, enhancing the therapeutic activity of several drugs and reducing their possible side effects. Consequently, melatonińs actions to manage KD need to be tested in further clinical studies.

Influence of Latitude on the Prevalence of Kawasaki Disease: A Retrospective Cohort Study from the Taiwan National Health Insurance Database and Review of the Literature

Background: Countries at higher latitudes have higher incidence rates of Kawasaki disease (KD) than do countries at lower latitudes in the Asian and West Pacific area. However, the precise influence of latitude on KD incidence rates requires further clarification. Methods: We searched the Longitudinal Health Insurance Database 2005 to retrieve patients’ medical records from 1996 to 2009. The patients with KD were categorized as living in northern, middle, and southern Taiwan; the period prevalence of KD for each area was determined. Climate variables, including temperature, sunshine duration, precipitation, and relative humidity, were collected from the Taiwan Central Weather Bureau. The effect of latitude on the period KD prevalence and the correlation between climate variables and KD prevalence were calculated. Results: After patients without complete data excluded, a total of 61,830 children up to 10 years old were retrieved, from which 404 patients with KD were recognized. The period prevalence of KD increased significantly with latitude (p = 0.0004). Climate variables associated with high temperature demonstrated a connection with KD prevalence; however, this correlation was not statistically significant. Conclusions: Our study demonstrated that higher latitude is associated with a higher KD prevalence in Taiwan.

Update on etio and immunopathogenesis of Kawasaki disease

PURPOSE OF REVIEW

This review first discusses the pathogenesis of Kawasaki disease based on the results of recently performed studies aimed at identifying Kawasaki disease-susceptibility genes and the results of analyses of the immune system. Following that, we discuss the findings generated using a murine Kawasaki disease arteritis model and speculate regarding the mechanism of Kawasaki disease onset based on immune function aberrations seen in that model.

RECENT FINDINGS

Recent advances in gene analysis studies of Kawasaki disease are contributing not only to prediction of disease susceptibility but also to improving our understanding of the pathogenesis of Kawasaki disease and development of new improved therapies. In addition, Th17/Treg imbalance is observed in patients with acute-phase Kawasaki disease. Th17/Treg imbalance may be an important factor causing disturbed immunological function. IL-17 induced by Th17 cells have proinflammatory properties and act on inflammatory cells, thereby inducing expression of cytokines and chemokines and resulting in tissue inflammation.

SUMMARY

Kawasaki disease vasculitis may be triggered by aberrant activation of inflammatory cytokines mediated by IL-17 that is produced by Th17 cells that have been activated by some infectious agent(s).

Tropospheric winds from northeastern China carry the etiologic agent of Kawasaki disease from its source to Japan

Evidence indicates that the densely cultivated region of northeastern China acts as a source for the wind-borne agent of Kawasaki disease (KD). KD is an acute, coronary artery vasculitis of young children, and still a medical mystery after more than 40 y. We used residence times from simulations with the flexible particle dispersion model to pinpoint the source region for KD. Simulations were generated from locations spanning Japan from days with either high or low KD incidence. The postepidemic interval (1987-2010) and the extreme epidemics (1979, 1982, and 1986) pointed to the same source region. Results suggest a very short incubation period (<24 h) from exposure, thus making an infectious agent unlikely. Sampling campaigns over Japan during the KD season detected major differences in the microbiota of the tropospheric aerosols compared with ground aerosols, with the unexpected finding of the Candida species as the dominant fungus from aloft samples (54% of all fungal strains). These results, consistent with the Candida animal model for KD, provide support for the concept and feasibility of a windborne pathogen. A fungal toxin could be pursued as a possible etiologic agent of KD, consistent with an agricultural source, a short incubation time and synchronized outbreaks. Our study suggests that the causative agent of KD is a preformed toxin or environmental agent rather than an organism requiring replication. We propose a new paradigm whereby an idiosyncratic immune response, influenced by host genetics triggered by an environmental exposure carried on winds, results in the clinical syndrome known as acute KD.

Etanercept suppresses arteritis in a murine model of kawasaki disease: a comparative study involving different biological agents

Coronary arteritis, a complication of Kawasaki disease (KD), can be refractory to immunoglobulin (IVIG) treatment. To determine the most effective alternative therapy, we compared the efficacy of different agents in a mouse model of KD. Vasculitis was induced by injection of Candida albicans water-soluble fractions (CAWS) into a DBA/2 mouse, followed by administration of IVIG, etanercept, methylprednisolone (MP), and cyclosporine-A (CsA). At 2 and 4 weeks, the mice were sacrificed, and plasma cytokines and chemokines were measured. CAWS injection induced active inflammation in the aortic root and coronary arteries. At 2 weeks, the vasculitis was reduced only by etanercept, and this effect persisted for the subsequent 2 weeks. At 4 weeks, IVIG and CsA also attenuated the inflammation, but the effect of etanercept was more significant. MP exerted no apparent effect at 2 or 4 weeks. The suppressive effect exerted by etanercept on cytokines, such as interleukin- (IL-)6, IL-12, IL-13, and tumor necrosis factor-α (TNF-α), was more evident than that of others. The extent of arteritis correlated with the plasma TNF-α levels, suggesting a pivotal role of TNF-α in KD. In conclusion, etanercept was most effective in suppressing CAWS-induced vasculitis and can be a new therapeutic intervention for KD.

Susceptibility to progressive Cryptococcus neoformans pulmonary infection is regulated by loci on mouse chromosomes 1 and 9

Genetic factors that regulate the pathogenesis of pneumonia caused by the fungus Cryptococcus neoformans are poorly understood. Through a phenotypic strain survey we observed that inbred C3H/HeN mice develop a significantly greater lung fungal burden than mice of the resistant CBA/J strain 4 weeks following intratracheal infection with C. neoformans ATCC 24067. The aim of the present study was to characterize the inflammatory response of C3H/HeN mice following C. neoformans pulmonary infection and to identify genetic loci that regulate host defense. Following cryptococcal infection, C3H/HeN mice demonstrated a Th2 immune response with heightened airway and tissue eosinophilia, goblet cell metaplasia, and significantly higher lung interleukin-5 (IL-5) and IL-13 protein expression relative to CBA/J mice. Conversely, CBA/J mice exhibited greater airway and tissue neutrophilia that was associated with significantly higher pulmonary expression of gamma interferon, CXCL10, and IL-17 proteins than C3H/HeN mice. Using the fungal burden at 4 weeks postinfection as a phenotype, genome-wide quantitative trait locus (QTL) analysis among 435 segregating (C3H/HeN × CBA/J)F2 (C3HCBAF2) hybrids identified two significant QTLs on chromosomes 1 (Cnes4) and 9 (Cnes5) that control susceptibility to cryptococcal pneumonia in an additive manner. Susceptible C3H/HeN mice carry a resistance allele at Cnes4 and a susceptibility allele at Cnes5. These studies reveal additional genetic complexity of the host response to C. neoformans that is associated with divergent patterns of pulmonary inflammation.

A Model of Left Ventricular Dysfunction Complicated by CAWS Arteritis in DBA/2 Mice

It was reported previously that a Candida albicans water-soluble fraction (CAWS), including a mannoprotein and β-glucan complex, has strong potency in inducing fatal necrotizing arteritis in DBA/2 mice. In this study, histopathological changes and cardiac function were investigated in this system. One mg/day of CAWS was given to DBA/2 mice via peritoneal injection for five days. The CAWS-treated DBA/2 mice were induced aortitis and died at an incidence of 100% within several weeks. Histological findings included stenosis in the left ventricular outflow tract (LVOT) and severe inflammatory changes of the aortic valve with fibrinoid necrosis. Cardiomegaly was observed and heart weight increased 1.62 fold (P < 0.01). Echocardiography revealed a severe reduction in contractility and dilatation of the cavity in the left ventricle (LV): LV fractional shortening (LVFS) decreased from 71% to 38% (P < 0.01), and the LV end-diastolic diameter (LVDd) increased from 2.21 mm to 3.26 mm (P < 0.01). The titer of BNP mRNA increased in the CAWS-treated group. Severe inflammatory changes resulting from CAWS brought about lethal LV dysfunction by aortic valve deformation with LVOT stenosis. This system is proposed as an easy and useful experimental model of heart failure because CAWS arteritis can be induced by CAWS injection alone.

Mizoribine provides effective treatment of sequential histological change of arteritis and reduction of inflammatory cytokines and chemokines in an animal model of Kawasaki disease

The incidence of panvasculitis in the coronary arteries and aortic root was 100% in the control group. The incidence of panvasculitis in the MZR group decreased to 50%. Moreover, the scope and severity of the inflammation of those sites were significantly reduced in the MZR group as well as the IgG group. On the other hand, increased cytokines and chemokines, such as IL-1α, TNF-α, KC, MIP-1α, GM-CSF, and IL-13, in the nontreatment group were significantly suppressed by treatment with MZR, but the MCP-1 level increased. In addition, IL-1α, TNF-α, IL-10, IL-13, and MIP-1α were suppressed by treatment in the IgG group.

BACKGROUND

Intravenous immunoglobulin (IVIg) treatment results in an effective response from patients with acute-phase Kawasaki disease (KD), but 16.5% of them remain nonresponsive to IVIg. To address this therapeutic challenge, we tried a new therapeutic drug, mizoribine (MZR), in a mouse model of KD, which we have established using injections of Candida albicans water-soluble fractions (CAWS).

METHODS

CAWS (4 mg/mouse) were injected intraperitoneally into C57BL/6N mice for 5 consecutive days. MZR or IgG was administered for 5 days. After 4 weeks, the mice were sacrificed and autopsied, the hearts were fixed in 10% neutral formalin, and plasma was taken to measure cytokines and chemokines using the Bio-Plex system.

RESULTS

The incidence of panvasculitis in the coronary arteries and aortic root was 100% in the control group. The incidence of panvasculitis in the MZR group decreased to 50%. Moreover, the scope and severity of the inflammation of those sites were significantly reduced in the MZR group as well as the IgG group. On the other hand, increased cytokines and chemokines, such as IL-1α TNF-α, KC, MIP-1α, GM-CSF, and IL-13, in the nontreatment group were significantly suppressed by treatment with MZR, but the MCP-1 level increased. In addition, IL-1α, TNF-α, IL-10, IL-13, and MIP-1α were suppressed by treatment in the IgG group.

CONCLUSION

MZR treatment suppressed not only the incidence, range, and degree of vasculitis, but also inflammatory cytokines and chemokines in the plasma of the KD vasculitis model mice, suggesting that MZR may be useful for treatment of KD.

Candida albicans-associated necrotizing vasculitis producing life-threatening gastrointestinal hemorrhage

Patients undergoing treatment of acute lymphoblastic leukemia are at risk for fungal infections including disseminated candidiasis. We describe a case of systemic Candida albicans infection associated with life-threatening gastrointestinal hemorrhage due to unusual necrotizing vasculitis involving the gastrointestinal tract. We explore the association between Candida and such vasculopathy.

IL-1B polymorphism in association with initial intravenous immunoglobulin treatment failure in Taiwanese children with Kawasaki disease

BACKGROUND

Approximately 8-38% of children with Kawasaki disease (KD) will have persistent or recrudescent fever after initial intravenous immunoglobulin (IVIG) treatment and are at increased risk for development of coronary artery abnormalities. Using genetic markers may be helpful to identify the high-risk group of IVIG-resistant patients for aggressive treatment. The aim of this study was to evaluate the associations between 4 potential polymorphisms in the interleukin (IL)-1 family of genes and initial IVIG treatment failure in KD children.

METHODS AND RESULTS

A total of 156 KD children (136 with and 20 without a response to IVIG treatment) who were treated with high-dose IVIG (2 g/kg) within 10 days of fever onset were recruited. Polymerase chain reaction and Taqman assays were used for genotyping. A significant increase in IVIG resistance risk was observed for IL-1B -511 TT and IL-1B -31 CC genotypes (adjusted odds ratio (AOR) 5.27, 95% confidence interval (CI) 1.69-16.38, P=0.004; AOR 3.95, 95%CI 1.26-12.41, P=0.019, separately). The diplotype TC/TC (at IL-1B -511 and -31) also showed a significantly increased risk of IVIG resistance (AOR 4.32, 95%CI 1.36-13.71, P=0.013).

CONCLUSIONS

The IL-1B -511 TT and IL-1B -31 CC genotypes or the TC/TC diplotype may be associated with initial IVIG treatment failure in Taiwanese children with KD.

Administration of human immunoglobulin suppresses development of murine systemic vasculitis induced with Candida albicans water-soluble fraction: an animal model of Kawasaki disease

We investigated the inhibitory effect of human immunoglobulin (h-Ig) on the development of coronary arteritis in a murine model of vasculitis induced with a Candida albicans water-soluble fraction (CAWS). CAWS was intraperitoneally injected to C57BL/6 mice for 5 days. Then h-Ig was administered according to various schedules. The animals were sacrificed in week 5, and the status of vasculitis in the coronary arteries and the aortic root was investigated histologically. The groups in which h-Ig was administered for 5 days from day 3 and from day 5 of the experiment showed a significant reduction in the incidence of panvasculitis. In addition, the scope and severity of the inflammation of the aortic root and the coronary arteries were reduced in both groups. In the group administered h-Ig for 5 days from day 1 and the group administered a high dose of h-Ig once on day 1 or day 3, no suppression of development of vasculitis was observed. The h-Ig acted by suppressing the generation and progression of vasculitis in this CAWS-induced murine vasculitis model.

Beta-mannosyl linkages negatively regulate anaphylaxis and vasculitis in mice, induced by CAWS, fungal PAMPS composed of mannoprotein-beta-glucan complex secreted by Candida albicans

Candida albicans water soluble fraction (CAWS) is a water-soluble extracellular mannoprotein-beta-glucan complex obtained from the culture supernatant of Candida albicans, which grows in a chemically defined medium. CAWS induced toxic reactions, such as acute anaphylactoid reaction, by intravenous administration and coronary arteritis by intraperitoneal administration. To clarify the structure responsible for these toxic reactions, C. albicans was cultured in pH- and temperature-controlled conditions and prepared with CAWS with or without the beta-1,2-linked mannosyl segment (BM). The structure of CAWS was assessed by immunochemical and spectroscopic methodologies, and we found that CAWS prepared under the natural culture conditions contained only small amounts of BM and CAWS prepared at neutral conditions at 27 degrees C contained a significantly higher percentage of BM. Both the acute lethal toxicity and coronary arteritis induction was significantly more severe in the absence of BM. Activation of a complement pathway, the lectin pathway, by CAWS was significantly stronger in the absence of BM. These facts strongly suggest that BM linkages in CAWS negatively modulate acute and chronic toxicity of CAWS, and may be strongly related to the lectin pathway of the complement activation.

Lethal and severe coronary arteritis in DBA/2 mice induced by fungal pathogen, CAWS, Candida albicans water-soluble fraction

CAWS is a microbial pathogen-associated molecular patterns (PAMPs) produced by Candida albicans. CAWS is a mannoprotein-beta-glucan complex and secreted into the culture supernatant. CAWS has various biological effects, causing acute shock and disrupting vascular permeability. Intraperitoneal administration of CAWS induces coronary arteritis in various strains of inbred mice. The CAWS-induced coronary arteritis is strain-dependent and most severe in DBA/2 mice with a significant number of these animals expiring with cardiomegaly during the observation period. In vivo and in vitro, splenocytes of DBA/2 mice produced various cytokines, such as IL-6, TNF-alpha, and IFN-gamma in response to CAWS. GM-CSF was also produced in response to CAWS. The production of cytokines was significantly enhanced in the presence of recombinant GM-CSF. In contrast, anti-GM-CSF significantly reduced the production of TNF-alpha and IFN-gamma. Augmented production of cytokines in response to CAWS would be a key to the severity of coronary arteritis.

[Anti-neutrophil cytoplasmic antibody MPO-ANCA related with disease activity of vasculitis]

Myeloperoxidase (MPO)-specific anti-neutrophil cytoplasmic antibodies (MPO-ANCA) are involved in the development of vasculitis microscopic polyangiitis, a systemic vasculitis etc. We have showed a correlation of MPO-ANCA epitopes in vasculitis concerning contribution of N and C terminus of MPO to severity of the diseases. On the other hand, a role of activated neutrophils in inflammatory nephritis renal lesions using SCG/Kj mice. In the phase of nephritis with a low grade of proteinuria, the spontaneous release of MPO from peripheral neutrophils increased, indicating that neutrophils are activated and contribute to the development of active crescentic lesions in SCG/Kj mice. In addition, we have investigated that mice having CADS/CAWS-induced vasculitis also are good model animals for the analysis of the production of MPO-ANCA. Furthermore, we have clarified that MPO is a major antigen for MPO-ANCA production using MPO knock mice.