Spontaneous tumor necrosis factor production in Kawasaki disease

Current knowledge of TNF-α monoclonal antibody infliximab in treating Kawasaki disease: a comprehensive review

Kawasaki disease (KD), an autoinflammatory disease primarily affecting young children, characterized by consisting of acute systemic vasculitis and coronary artery involvement in severe cases. Intravenous immunoglobulin gamma (IVIG) combined with aspirin therapy is the first-line regimen for the prevention of coronary aneurysms in the acute phase of KD. The etiology and pathogenesis of KD are unclear, but its incidence is increasing gradually, especially in the cases of IVIG-naïve KD and refractory KD. Conventional therapies for refractory KD have unsatisfactory results. At present, infliximab (IFX), a human-murine chimeric monoclonal antibody that specifically blocks tumor necrosis factor-α (TNF-α), has made great progress in the treatment of KD. This review revealed that IFX infusion (5 mg/kg) could effectively modulate fever, reduce inflammation, improve arthritis, diminish the number of plasma exchange, decrease hospitalizations, and prevent the progression of coronary artery lesions. The adverse effects of IFX administration included skin rash, arthritis, respiratory disease, infusion reaction, hepatomegaly, and vaccination-associated complications. But the incidence of these adverse effects is low. The clear optimal application protocol of the application of IFX for either initial combination therapy or salvage therapy in KD is still under investigation. In addition, there are no effective biomarkers to predict IFX resistance. Further multicenter trials with large sample size and long-term follow-up are still needed to validate the clinical efficacy and safety of IFX for IVIG-resistant KD or refractory KD.

Adipose tissue-derived stem cells suppress coronary arteritis of Kawasaki disease in vivo

BACKGROUND

Kawasaki disease (KD) is a systemic inflammatory disease resulting in an acute febrile syndrome commonly affecting children younger than 5 years. Coronary arteritis in KD is occasionally non-responsive to several treatments. Recently, adipose tissue-derived stem cells (ADSCs) have been shown to have anti-inflammatory, immunosuppressive, and tissue-repair characteristics and are considered a useful treatment for inflammatory disease. The present study aimed to elucidate whether the administration of ADSCs can suppress KD-associated vasculitis in vivo.

METHODS

Candida albicans water-soluble fraction is often used to model KD via the induction of severe coronary arteritis. Kawasaki disease model mice were intravenously administered ADSCs and phosphate-buffered saline (PBS). On day 29, the mice were sacrificed and hearts from mice in each group were dissected. This was followed by serum collection. Cardiac tissue sections were subjected to histopathological examination to evaluate the inflammatory area. The levels of pro-inflammatory cytokines in the serum were analyzed at days 15 and 29. The survival rates of both groups were compared.

RESULTS

The mean inflammatory area in coronary arteritis was significantly lower in the ADSC group compared to the PBS group (P < 0.01). Furthermore, the levels of pro-inflammatory cytokines, such as IL-1β, IL-12, IL-17, RANTES, INF-γ, and TNF-α, in the ADSC group were significantly lower than those in the PBS group. Moreover, the ADSC group had a significantly higher survival rate than the PBS group.

CONCLUSIONS

These findings highlight that ADSCs have anti-inflammatory and immune regulatory functions that could provide novel cell-based therapeutic strategies for severe KD.

History and Future of Treatment for Acute Stage Kawasaki Disease

Kawasaki disease is a form of vasculitis, mainly in small and medium arteries of unknown origin, occurring frequently in childhood. It is the leading form of childhood-onset acquired heart disease in developed countries and leads to complications of coronary artery aneurysms in approximately 25% of cases if left untreated. Although more than half a century has passed since Professor Tomisaku Kawasaki's first report in 1957, the cause is not yet clear. Currently, intravenous immunoglobulin therapy has been established as the standard treatment for Kawasaki disease. Various treatment strategies are still being studied under the slogan, "Ending powerful inflammation in the acute phase as early as possible and minimizing the incidence of coronary artery lesions," as the goal of acute phase treatments for Kawasaki disease. Currently, in addition to immunoglobulin therapy, steroid therapy, therapy using infliximab, biological products, suppression of elastase secretion inside and outside the neutrophils, inactivated ulinastatin therapy and cyclosporine therapy, plasma exchange, etc. are performed. This chapter outlines the history and transition of the acute phase treatment for Kawasaki disease.

Tumor necrosis factor-α-308 polymorphism is not associated with Kawasaki disease: A meta-analysis of case-control studies

BACKGROUND

Genetic factors in the pathogenesis of Kawasaki disease (KD) have received a lot of attention during the past decade. Some studies have reported that tumor necrosis factor (TNF)-α-308 polymorphism has been associated with KD. However, there have been inconsonant results among different studies. To increase the power for clarifying the influence of TNF on KD, a meta-analysis of case-control studies were performed.

METHODS

The following databases were searched to identify related studies: PubMed, Embase, Cochrane Library, CNKI, Wanfang, and VIP databases according to the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. Search terms included "Kawasaki disease" or "KD," "tumor necrosis factor-alpha" or "TNF-α," and "polymorphism" or "mutation." Two reviewers independently extracted data and assessed study quality using Newcastle-Ottawa Scale. Odds ratios (ORs) with corresponding 95% confidence intervals (CI) were used to assess the strength of the association. Accounting for heterogeneity, a fixed or random effects model was respectively adopted. Heterogeneity was checked using the Q test and the I statistic. A cumulative meta-analysis was conducted to estimate the tendency of pooled OR. Funnel plots and Egger tests were performed to test for possible publication bias and sensitivity analyses were done to ensure authenticity of the outcome.

RESULTS

Eleven separate studies were suitable for the inclusion criterion. The selected studies contained 2582 participants, including 841 in KD group and 1741controls. The pooled odds ratio of G versus A with the random effect model was 1.09 (95% CI = 0.69-1.70, P = .72) and the genotype effects for GG versus GA+AA was 1.14 (95% CI = 0.68-1.90, P = .62) in the whole population separately. Unfortunately, no significant association was detected between the TNF-α-308 polymorphism and KD risk under allele and genotype model.

CONCLUSION

No association between the TNF-α-308 polymorphism and KD was found in our meta-analysis and further studies with larger sample size and more ethnicities are expected to be conducted in the future to validate the results.

Characterization of a murine model with arteritis induced by Nod1 ligand, FK565: A comparative study with a CAWS-induced model

OBJECTIVE

Kawasaki disease (KD) occurs via activation of the innate immune system. Nucleotide oligomerization domain-1 (NOD1) is a pattern recognition receptor regulating the innate immunity. We characterized histopathology of arteritis induced by FK565, a ligand for NOD1, in mice, compared with Candida albicans water-soluble fraction (CAWS)-induced model.

METHODS

Vasculitis was induced by injection of FK565 or CAWS into C57BL6/J mice (n = 9 and n = 11, respectively). At 4 weeks, they were sacrificed, and plasma cytokines and chemokines were measured.

RESULTS

FK565 injection induced vasculitis mainly involving bilateral coronary arteries whereas the aortic root was diffusely affected in CAWS mice. In FK565 animals, the abdominal aorta and its branching arteries also exhibited inflammation with atherosclerosis. IL-1α, IL-1β, IL-5 and RANTES were increased in FK565 group whereas IL-6, IL-13, G-CSF, IFN-γ, and TNF-α were higher in CAWS animals (p < .05 for all variables). The total area of inflammation in FK565 mice appeared to correlate with IL-1β levels (r = 0.71, p = .05).

CONCLUSIONS

Histopathology of FK565-induced model demonstrated 'site-specific' coronary arteritis mimicking KD. This histopathological difference from CAWS model may be due to different cytokine expression profiles.

Cordycepin inhibits lipopolysaccharide (LPS)-induced tumor necrosis factor (TNF)-α production via activating amp-activated protein kinase (AMPK) signaling

Tumor necrosis factor (TNF)-α is elevated during the acute phase of Kawasaki disease (KD), which damages vascular endothelial cells to cause systemic vasculitis. In the current study, we investigated the potential role of cordycepin on TNFα expression in both lipopolysaccharide (LPS)-stimulated macrophages and ex vivo cultured peripheral blood mononuclear cells (PBMCs) of KD patients. We found that cordycepin significantly suppressed LPS-induced TNFα expression and production in mouse macrophages (RAW 264.7 cells and bone marrow-derived macrophages (BMDMs)). Meanwhile, cordycepin alleviated TNFα production in KD patients’ PBMCs. PBMCs from healthy controls had a much lower level of basal TNF-α content than that of KD patients. LPS-induced TNF-α production in healthy controls’ PBMCs was also inhibited by cordycepin. For the mechanism study, we discovered that cordycepin activated AMP-activated protein kinase (AMPK) signaling in both KD patients’ PBMCs and LPS-stimulated macrophages, which mediated cordycepin-induced inhibition against TNFα production. AMPK inhibition by its inhibitor (compound C) or by siRNA depletion alleviated cordycepin’s effect on TNFα production. Further, we found that cordycepin inhibited reactive oxygen species (ROS) production and nuclear factor kappa B (NF-κB) activation in LPS-stimulate RAW 264.7 cells or healthy controls’ PBMCs. PBMCs of KD patients showed higher basal level of ROS and NF-κB activation, which was also inhibited by cordycepin co-treatment. In conclusion, our data showed that cordycepin inhibited TNFα production, which was associated with AMPK activation as well as ROS and NF-κB inhibition. The results of this study should have significant translational relevance in managing this devastating disease.

Perifosine inhibits lipopolysaccharide (LPS)-induced tumor necrosis factor (TNF)-α production via regulation multiple signaling pathways: new implication for Kawasaki disease (KD) treatment

Kawasaki disease (KD) is a multisystem vasculitis of unknown etiology, with coronary artery aneurysms occurring in majority of untreated cases. Tumor necrosis factor (TNF)-α is the pleiotropic inflammatory cytokine elevated during the acute phase of KD, which induces damage to vascular endothelial cells to cause systemic vasculitis. We here investigated the potential role of perifosine, a novel Akt inhibitor, on TNFα expression in LPS-stimulated macrophages and in ex-vivo cultured peripheral blood mononuclear cells (PBMCs) of acute KD patients. Here, we found that perifosine inhibited LPS-induced TNFα expression and production in mouse macrophages (RAW 264.7 cells and bone marrow-derived macrophages (BMDMs)). Meanwhile, perifosine administration down-regulated TNFα production in PBMCs isolated from acute KD patients. For the mechanism study, we found that perifosine significantly inhibited Akt and ERK/mitogen-activated protein kinases (MAPK) signaling, while activating AMP-activated protein kinase (AMPK) signaling in both patients' PBMCs and LPS-stimulated macrophages. Interestingly, although perifosine is generally known as an Akt inhibitor, our data suggested that ERK inhibition and AMPK activation, but not Akt inactivation were possibly involved in perifosine-mediated inhibition against TNFα production in monocytes. In conclusion, our data suggested that perifosine significantly inhibited TNFα production via regulation multiple signaling pathways. The results of this study should have significant translational relevance in managing this devastating disease.

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.

A systematic review and meta-analysis of tumor necrosis factor α-308 polymorphism and Kawasaki disease

BACKGROUND

There have been genetic studies assessing the association between tumor necrosis factor (TNF)-α-308 and Kawasaki disease (KD) but the results have been conflicting due to lack of power. Therefore, a systematic review and meta-analysis was conducted to increase the power for identifying the association between the TNF-α-308 polymorphism and KD.

METHOD

Studies were identified from MEDLINE and EMBASE databases and were included if the subjects were children and the frequencies between TNF-α-308 and KD were reported. Data were pooled using a random effect model if heterogeneity between studies was present.

RESULTS

Thirteen studies were identified however only six studies were included. The pooled prevalence of minor A allele was 5.2% (95% confidence interval [CI]: 0.1%-9.5%). Gene effect was assessed using per-allele and per-genotype approaches. The pooled odds ratio of G versus A with the random effect model was 1.13 (95%CI: 0.34-3.27). The genotype effects for GG versus GA+AA was estimated and the pooled odds ratio was 1.08 (95%CI: 0.42-2.92).

CONCLUSION

This review suggests a trend of association between the TNF-α-308 G-allele and KD. However, the gene effects are heterogeneous and assessing sources of heterogeneity are limited. An updated meta-analysis is needed if more studies are published.

Serum resistin concentrations in children with Kawasaki disease

OBJECTIVE

Human resistin is expressed strongly in monocytes or macrophages rather than in adipocytes and may play a pivotal role in inflammation. We hypothesize that resistin levels are elevated in patients with Kawasaki disease (KD) in the acute phase and may be associated with the disease severity.

DESIGN AND SUBJECTS

Serum resistin concentrations were measured in 44 Japanese children with KD and 17 age-matched healthy children. All the KD patients were given both aspirin and a single dose of intravenous immunoglobulin (IVIG).

RESULTS

The serum resistin levels at baseline in KD children were significantly higher than those in controls [33.0 (21.6-45.3) vs. 14.8 (12.4-18.6) ng/mL, P < 0.001]. After IVIG therapy, serum resistin levels were significantly decreased to normal control levels. No significant difference in baseline resistin levels was found between the high-risk group and the low-risk group of coronary artery aneurysms.

CONCLUSIONS

We confirmed that resistin was an acute inflammatory protein, but its concentrations were unlikely to predict the prognosis of disease in acute KD patients.

Circulating interleukin 17 is increased in the acute stage of Kawasaki disease

OBJECTIVES

During the acute phase, patients with Kawasaki disease (KD), an acute systemic vasculitis, demonstrate a drastic increase in serum interleukin-6 (IL-6), which parallels the duration of the fever. Recently, IL-17 has been reported to induce IL-6 production. The aim of this study was to elucidate the involvement of IL-17 in the pathogenesis of KD.

METHODS

Serum samples were obtained from patients with KD (n=30) and normal controls (n=20), and the concentrations of IL-17 and IL-6 measured using enzyme-linked immunosorbent assay (ELISA).

RESULTS

Compared with the normal controls (2.08 +/- 2.14 pg/mL), serum IL-17 was markedly elevated in patients with acute KD (25.47 +/- 5.05 pg/mL): levels gradually decreased in the subacute phase (5.94 +/- 2.83 pg/mL). In the acute phase, levels of IL-6 were 83.52 +/- 19.12 pg/L, which correlated well with the serum levels of IL-17.

CONCLUSION

These results suggest that IL-17 may be involved in the development of, or the effects of inflammation in KD.

Coronary artery fistula associated with Kawasaki disease

BACKGROUND

The aim of this study was to investigate the rate, risks factors, and clinical impact of coronary artery fistula (CAF) in Kawasaki disease (KD).

METHODS

From February 1999 to December 2007, a total of 325 pediatric patients fulfilled the diagnostic criteria of KD and admitted for intravenous immunoglobulin treatment were enrolled in this study. Patients with and without CAF were designated as group 1 and group 2, respectively. Patients of group 1 were further subdivided as with and without coronary artery lesions (CALs). The clinical presentations, laboratory data, and outcomes were compared among the groups.

RESULTS

The mean age of the 325 patients was 21.1 months. Group 1 had 17 patients, and group 2 had 308 patients. The rate of CAF in KD was 5.3%. There were significant differences between group 1 and group 2 patients regarding age (11.8 +/- 1.8 vs 21.5 +/- 1.2 months, P = .01), the presence of CAL (64.7% vs 25%, P < .01), white blood cell counts (16.4 +/- 1.3 vs 13.5 +/- 0.3 x 10(3)/mm(3), P = .01), and platelet counts (432.1 +/- 39.1 vs 346.4 +/- 8.4 x 10(3)/mm(3), P = .02). Spontaneous closure of CAF was observed in 7 (41%) of the 17 patients during follow-up (mean 45 months). Group 1 patients without CAL had a more benign clinical course (total fever day 5.8 +/- 0.6 vs 8.6 +/- 0.8, P = .03) and higher spontaneous closure rate (5/6 vs 2/11, P = .035) than patients with CAL.

CONCLUSIONS

Patients of young age, CAL, high white blood cell counts, and high platelet counts have higher rate of CAF formation. Approximately 5% KD patients may associate with CAF, but most of them have good clinical outcome during follow-up.

Activated myeloid dendritic cells accumulate and co-localize with CD3+ T cells in coronary artery lesions in patients with Kawasaki disease

Emerging evidence implicating the participation of dendritic cells (DCs) and T cells in various vascular inflammatory diseases such as giant cell arteritis, Takayasu's arteritis, and atherosclerosis led us to hypothesize that they might also participate in the pathogenesis of coronary arteritis in Kawasaki disease (KD). Coronary artery specimens from 4 patients with KD and 6 control patients were obtained. Immunohistochemical and computer-assisted histomorphometric analyses were performed to detect all myeloid DCs (S-100(+), fascin(+)), all plasmacytoid DCs (CD123(+)) as well as specific DC subsets (mature myeloid DCs [CD83(+)], myeloid [BDCA-1(+)] and plasmacytoid DC precursors [BDCA-2(+)]), T cells (CD3(+)), and all antigen-presenting cells (HLA-DR(+)). Co-localization of DCs with T cells was assessed using double immunostaining. Significantly more myeloid DCs at a precursor, immature or mature stage were found in coronary lesions of KD patients than in controls. Myeloid DC precursors were distributed equally in the intima and adventitia. Mature myeloid DCs were particularly abundant in the adventitia. There was a significant correlation between mature DCs and HLA-DR expression. Double immunostaining demonstrated frequent contacts between myeloid DCs and T cells in the outer media and adventitia. Plasmacytoid DC precursors were rarely found in the adventitia. In conclusion, coronary artery lesions of KD patients contain increased numbers of mature myeloid DCs with high HLA-DR expression and frequent T cell contacts detected immunohistochemically. This suggests that mature arterial myeloid DCs might be activating T cells in situ and may be a significant factor in the pathogenesis of coronary arteritis in KD.

Epidemiology and etiology of Kawasaki disease

Kawasaki disease was first reported in Japan in 1967 by Dr. Tomisaku Kawasaki. It has since been recognized worldwide, and in at the United States and Japan is the most important cause of acquired heart disease in children, surpassing other more recognized conditions such as rheumatic fever, endocarditis and myocarditis. It is primarily a disease of children less than 5 years of age but has been reported in older children and adults. Risk factors for the illness include Asian ancestry, male gender and certain familial predispositions. Observations such as similarity to certain exanthematous infectious diseases, temporal-geographic clustering of cases and seasonality in incidence favors an infectious etiology. Pathology and pathogenesis of the disease indicate that it is a medium-sized artery vasculitis that results from a dramatic immune activation that in most cases reversed by immune modulating agents such as intravenous immunoglobulin. Unfortunately, the etiology of the illness remains obscure, although recent studies favor a possible viral etiology.

The pathophysiology of coronary artery aneurysms in Kawasaki disease: role of matrix metalloproteinases

Kawasaki disease is an acute inflammatory syndrome that takes the form of systemic vasculitis, and predominantly affects children. Important complications of this disease are coronary artery dilation and aneurysm formation. Recent studies indicate that Kawasaki disease patients have elevated expression, activity, or protein levels of matrix metalloproteinases (MMPs), and suggest that imbalances in MMPs or MMP/tissue inhibitor of MMP (TIMP) play important pathophysiological roles in the development of coronary artery lesions in this disease. However, it remains unclear whether MMP activities at the site of coronary artery lesions are indeed increased. Further studies on the effects of MMP inhibition on coronary outcome are needed to define the roles of MMPs and TIMPs in the formation of coronary artery lesions in Kawasaki disease; findings of such studies may support the use of MMP inhibitors for the prevention of coronary artery complications in patients with this disease.

Anti-inflammatory effect of intravenous immunoglobulin in comparison with dexamethasone in vitro: implication for treatment of Kawasaki disease

High-dose intravenous immunoglobulin (IVIG) is a well-established standard therapy for Kawasaki disease (KD) that reduces the risk of developing coronary artery aneurysms. On the other hand, some reports have recommended an alternative therapy with steroids for KD patients. In this study we investigated the anti-inflammatory effect of IVIG in comparison with dexamethasone at clinical doses in vitro. High-dose IVIG inhibited tumor necrosis factor-alpha (TNF-alpha)-induced activation of nuclear factor-kappaB (NF-kappaB) to a greater degree than dexamethasone in human monocytic U937 cells and human coronary arterial endothelial cells (HCAEC), but not in human T lymphocytic Jurkat cells. IVIG was more potent than dexamethasone in reducing the expression of CD16 (FcgammaRIII) in human monocytic THP-1 cells stimulated with lipopolysaccharide and in Jurkat cells stimulated with dimethyl sulfoxide. In HCAEC exposed to TNF-alpha, IVIG and dexamethasone inhibited interleukin-6 production to a similar degree, whereas the expression of E-selectin was inhibited more strongly by IVIG. Our results show that high-dose IVIG inhibits the activation of monocytes/macrophages and coronary arterial endothelial cells more strongly than that of T cells, whereas dexamethasone inhibits the activation of all three cell types. These findings suggest that IVIG or dexamethasone therapy should be chosen to match the types of cells that are activated during acute KD.

TNF-alpha is necessary for induction of coronary artery inflammation and aneurysm formation in an animal model of Kawasaki disease

Kawasaki disease is the most common cause of multisystem vasculitis in childhood. The resultant coronary artery lesions make Kawasaki disease the leading cause of acquired heart disease in children in the developed world. TNF-alpha is a pleiotropic inflammatory cytokine elevated during the acute phase of Kawasaki disease. In this study, we report rapid production of TNF-alpha in the peripheral immune system after disease induction in a murine model of Kawasaki disease. This immune response becomes site directed, with migration to the coronary arteries dependent on TNF-alpha-mediated events. Production of TNF-alpha in the heart is coincident with the presence of inflammatory infiltrate at the coronary arteries, which persists during development of aneurysms. More importantly, inflammation and elastin breakdown in the coronary vessels are completely eliminated in the absence of TNF-alpha effector functions. Mice treated with the TNF-alpha-blocking agent etanercept, as well as TNFRI knockout mice, are resistant to development of both coronary arteritis and coronary aneurysm formation. Taken together, TNF-alpha is necessary for the development of coronary artery lesions in an animal model of Kawasaki disease. These findings have important implications for potential new therapeutic interventions in children with Kawasaki disease.

Arthritis presenting during the acute phase of Kawasaki disease

OBJECTIVE

To define the prevalence, pattern, and clinical course of arthritis presenting at the time of diagnosis of Kawasaki disease.

STUDY DESIGN

A single-center, retrospective study of 414 consecutive patients diagnosed with Kawasaki disease between January 1997 and December 2002 was performed. Standardized clinical assessments, laboratory and imaging test results, and treatment regimens were reviewed. The clinical, laboratory, treatment response, and coronary outcome data were analyzed for children with and without arthritis.

RESULTS

The prevalence of arthritis was 7.5% (31/414). In the 31 children with arthritis, 55% had oligoarticular involvement and 45% had polyarticular involvement. In both of these groups, the large joints were predominantly involved. Some 88% of the children with arthritis responded to standard intravenous immunoglobulin therapy for acute Kawasaki disease and did not require additional medications. The children with arthritis had significantly increased levels of inflammatory markers, but their demographical and clinical features were otherwise similar to those of the children without arthritis, including coronary outcome, with the same proportion (13%) of children from each group having coronary artery lesions (z-score > or = 2.5).

CONCLUSIONS

Arthritis is a short-lived phenomenon included in the clinical spectrum of acute Kawasaki disease. Children with arthritis have evidence of increased systemic inflammation but otherwise share the same clinical features, response to treatment, and coronary outcomes as patients without arthritis. Most cases of arthritis resolve without additional therapeutic intervention.

Immunological profile of peripheral blood lymphocytes and monocytes/macrophages in Kawasaki disease

Kawasaki disease (KD) is an acute illness of early childhood characterized by prolonged fever, diffuse mucosal inflammation, indurative oedema of the hands and feet, a polymorphous skin rash and nonsuppurative lymphadenopathy. The histopathological findings in KD comprise panvasculitis with endothelial necrosis, and the infiltration of mononuclear cells into small and medium-sized blood vessels. The levels of many proinflammatory cytokines, chemokines and adhesion molecules can be elevated in sera from children with KD at the acute stage. Although many immunological studies on KD involving peripheral blood have been reported, the data obtained remain controversial. This review focuses on the immune response of peripheral blood lymphocytes and monocytes/macrophages during acute KD.

Adrenomedullin is highly expressed in blood monocytes associated with acute Kawasaki disease: a microarray gene expression study

Kawasaki disease (KD) is an acute inflammatory disorder of children frequently associated with the development of coronary artery abnormalities. Although a great deal is known about inflammatory and immune responses in acute KD, the mechanisms linking the immune response to vascular changes are not known. To gain further insight into this process, we performed a microarray gene expression analysis on RNA isolated from the peripheral blood mononuclear cells of four patients with KD during both their acute and convalescent phases. Forty-seven genes of 7129 genes examined showed an increased expression in three or all four patients in the acute compared with the convalescent phase of KD. Fourteen of these genes were significantly (p < 0.05) up-regulated, including several inflammatory response genes (e.g. S-100 A9 protein) and also anti-inflammatory genes (e.g. TSG-6). Of greatest interest, the adrenomedullin (ADM) gene, known to be associated with coronary artery vasodilation, was up-regulated in the acute phase of KD (p = 0.024). Up-regulation of ADM in the acute phase of KD was confirmed in peripheral blood mononuclear cells of 11 additional KD patients by reverse transcriptase-PCR (p < 0.01). Isolated blood monocytes but not lymphocytes were demonstrated by real-time PCR to have increased ADM mRNA (p = 0.01). Plasma ADM protein level in 32 additional KD patients was also confirmed to be higher in acute KD compared with convalescent KD (p < 0.032). It is interesting that from microarray results, other molecules known to be associated with coronary dilation, including nitric oxide, prostacyclin, acetylcholine, bradykinin, substance P, and serotonin, were not elevated in acute KD. Our current study suggests that ADM-expressing monocytes that infiltrate the coronary vascular wall may be the cause of coronary dilation in the acute phase of KD.

Cytokine mRNA repertoire of peripheral blood mononuclear cells in Takayasu's arteritis

We have investigated constitutive and phytohaemagglutinin (PHA) + phorbol 12-myristate 13-acetate (PMA)-induced gene expression of tumour necrosis factor (TNF)-alpha, interferon (IFN)-gamma, interleukin (IL)-2, IL-3, IL-4, IL-10, IL-12 and granulocyte macrophage colony-stimulating factor (GM-CSF) in peripheral blood mononuclear cells (PBMCs) of 10 patients with Takayasu's arteritis (TA) and 10 healthy controls by semiquantitative reverse transcriptase polymerase chain reaction (RT-PCR). The constitutive mRNA expression of TNF-alpha (69.0 +/- 4.0%versus 27.5 +/- 18.0%; P = 0.001) and IL-4 (60.0 +/- 10.0%versus 0%; P = 0.001) was significantly higher in patients than controls; that of IL-3 was comparable in both groups (38.0 +/- 6.0%versus 32.0 +/- 5.0%; P = 0.651) while no constitutive mRNA expression was observed for the other cytokines studied. The stimulated PBMCs of patients, as compared with the controls, had higher mRNA gene expression of TNF-alpha (127.0 +/- 16.0%versus 54.0 +/- 6.0%; P = 0.001), IFN-gamma (93.0 +/- 13.0%versus 57.0 +/- 5.0%; P = 0.032), IL-2 (109.0 +/- 13.0%versus 68.0 +/- 6.0%; P = 0.015), IL-3 (60.0 +/- 8.0%versus 21.2 +/- 3.0%; P = 0.045) and IL-4 (68.0 +/- 7.0%versus 27.0 +/- 7.2%; P = 0.01) The mRNA expression of IL-10 was lower in patients than controls (35.0 +/- 8.0%versus 75.0 +/- 12.0%; P = 0.022). The GM-CSF mRNA was similar (102.0 +/- 6.0%versus 89.0 +/- 5.0%; P = 0.475) in both groups. Stimulation of cells with PHA + PMA showed no IL-12 expression but stimulation with lipopolysaccharide induced higher IL-12 mRNA in patients than controls (83.0 +/- 14.0%versus 33.0 +/- 4.0%; P = 0.005). Our data suggest that an inflammatory cytokine signature exists in TA with a key role for TNF-alpha, IL-4, IL-10 and IL-12 in different pathological processes of the disease.

Presence of IFN-gamma does not indicate its necessity for induction of coronary arteritis in an animal model of Kawasaki disease

Kawasaki disease is the most common cause of vasculitis affecting children, and the leading cause of acquired heart disease in the developed world. To date, studies on the role of IFN-gamma in the pathogenesis of Kawasaki disease have focused on peripheral production of IFN-gamma, and have yielded conflicting results. Affected heart tissue is not available from children with Kawasaki disease. In this study, we use an animal model of Kawasaki disease, Lactobacillus casei cell wall extract (LCWE)-induced coronary arteritis, to examine the role of IFN-gamma in the development of coronary artery lesions. We report the presence of IFN-gamma, both at the mRNA and protein levels, in the affected vessels. Its biphasic expression, first at days 3-7 and again at days 28-42 post-LCWE injection, corresponds to the first appearance of inflammatory infiltrate in coronary arteries, and later to vascular wall disruption and aneurysm formation, respectively. Interestingly, ablation of IFN-gamma expression did not dampen the inflammatory response, and IFN-gamma-deficient lymphocytes proliferated more vigorously in response to LCWE than those of wild-type animals. Of more importance, the incidence of coronary arteritis was the same in IFN-gamma-deficient and wild-type mice. Taken together, our findings demonstrate that IFN-gamma regulates the immune response during development of coronary arteritis, but is not required for the induction of coronary artery disease.

Intravenous immunoglobulin inhibits NF-kappaB activation and affects Fcgamma receptor expression in monocytes/macrophages

High-dose intravenous immunoglobulin (IVIG) therapy is well established as a standard therapy for Kawasaki disease (KD) that reduces the risk of developing coronary artery aneurysms. Activation of monocytes/macrophages and tumor necrosis factor-alpha (TNF-alpha) activity are responsible for severe vascular injury in acute KD. We examined whether or not IVIG inhibits TNF-alpha-induced activation of transcription factor NF-kappaB, a factor that is essential for the expression of proinflammatory cytokines, in human monocytic U-937 cells. The inhibitory effect of IVIG on NF-kappaB activation induced by TNF-alpha was evaluated by Western blotting and flow cytometry. In addition, we examined the effect of IVIG on the expression of FcgammaIII (CD16) and FcgammaRIIb (CD32b) in U-937 cells and peripheral blood CD14+ monocytes/macrophages by flow cytometry. Western blotting demonstrated that IVIG inhibits NF-kappaB activation in U-937 cells, and flow cytometry that IVIG inhibits NF-kappaB activation in U-937 cells in a dose-related manner. Western blotting of cytoplasmic extracts of U-937 cells revealed that IVIG inhibited degradation of the IkappaBalpha protein. Moreover, flow cytometry demonstrated that IVIG decreased the expression of FcgammaRIII in U-937 cells and peripheral blood CD14+ monocytes/macrophages. However, Western blotting revealed that IVIG did not affect the quantity of FcgammaRIII protein, and PCR that IVIG did not affect the quantity of FcgammaRIII mRNA in the cells. These findings suggest that IVIG inhibits TNF-alpha-induced NF-kappaB activation in monocytes/macrophages, and blocks FcgammaRIII on the membranes of monocytes/macrophages.

Plasminogen activator inhibitor-1 in patients with Kawasaki disease: diagnostic value for the prediction of coronary artery lesion and implication for a new mode of therapy

Kawasaki disease (KD) in children takes the form of acute systemic vasculitis, which causes coronary artery dilation and aneurysm formation in 10% to 15% of the patients. We have recently shown that matrix metalloproteinases (MMPs) are intimately involved in coronary arterial wall destruction and the resultant formation of coronary artery lesions (CALs) in this disease. Plasminogen activators (PAs) are known to be a major pathway of MMP activation, and this suggests that their inhibitor, plasminogen activator inhibitor-1 (PAI-1), also plays important roles in the development of CALs in KD. The present study was conducted to test the hypothesis that circulating levels of PAI-I are related to CAL formation in KD. Plasma levels of PAI-1 were measured by enzyme-linked immunoassay in 37 KD patients without CALs (group 1) and 7 KD patients with CALs (group 2). Blood samples were obtained before and after i.v. gammaglobulin therapy (IVGG), and in the convalescent stage. Levels of PAI-1 were significantly higher in KD patients before IVGG than in 18 age-matched healthy control subjects (p < 0.01). More importantly, both pre-IVGG and post-IVGG levels of PAI-1 were significantly higher in group 2 than in group 1 (p < 0.01). Furthermore, PAI-1 levels of 9 patients from group 1 who showed pre-IVGG PAI-1 levels higher than the minimum PAI-1 level in group 2 significantly decreased after IVGG, whereas PAI-1 levels of group 2 patients remained persistently elevated, further suggesting a close association between PAI-1 and CAL development in KD. Thus, PAI-1 may be useful as a predictive marker for CAL development in KD. Studies of the effects of PA inhibition on coronary outcome may provide evidence that PA is a viable therapeutic target for the prevention of KD-related CALs.

The role of anti-endothelial cell antibodies in Kawasaki disease - in vitro and in vivo studies

Kawasaki disease (KD) is a systemic vasculitis with cardiac and noncardiac complications. Anti--endothelial cell antibodies (AECA) are found among many patients with KD. The aim of this study was to investigate the pathogenic role of AECA in KD using in vitro and in vivo experimental models. F(ab)2 fragments of IgG-AECA and IgM-AECA were affinity purified from a patient with active KD. Their endothelial binding and ability to induce a pro-adhesive and a pro-inflammatory phenotype were evaluated in vitro. Twenty Balb/C mice were immunized with KD-AECA or with control Ig (N-Ig) to induce AECA in a murine model by the idiotypic manipulation method. Both KD-AECA isotypes bind significantly to human umbilical vein endothelial cell (HUVEC) compared to N-Ig. The in vitro activity was demonstrated by the antibodies ability to activate endothelial cells resulting in increased IL-6 secretion, adhesion molecule expression and monocytic cell line (U937) adherence to HUVEC. Five of the mice that received KD-AECA developed murine AECA after 3 months. None of the mice that received N-Ig produced AECA. The murine AECA increased monocyte adhesion to EC in vitro, similarly to the AECA used for immunization. Furthermore, all the mice that developed AECA had proteinuria and IgG deposition in the renal mesangium. No histological or immunofluorescence evidence of cardiac vasculitis could be detected. AECA might play a role in the emergence of some of KD manifestations.

Interleukin 6 gene promoter polymorphism is not associated with Kawasaki disease

We examined the IL-6 gene promoter and detected several interesting promoter polymorphisms: GGGCTG insertion at +162 bp and G deletion at +168 bp positions (M1), A to G substitution at -594 bp (M2) of the reported IL-6 promoter sequence. Other rare variations were also observed at several positions: -583 bp (T insertion), -507 bp (C insertion), -71 bp (T deletion), +17 bp (C insertion), and +121 bp (GC insertion). Although Kawasaki disease (KD) patients demonstrate a drastic increase in serum interleukin-6 (IL-6) during the acute phase that parallels the duration of fever, there were no significant differences in the nucleotide sequence between the KD patients and normal control group. By transient transfection with IL-6 gene promoter-luciferase fusion plasmids into CV-1 cells, we tested the functional significances of the polymorphisms. Mutations at +162 bp, +168 bp and -594 bp significantly decreased luciferase expression (P < 0.05), suggesting the promoter elements flanking the mutated nucleotides are important in transcriptional activation.

Maturation of macrophages from peripheral blood monocytes in Kawasaki disease: immunocytochemical and immunoelectron microscopic study

Kawasaki disease (KD) is regarded as a cytokine-associated disorder. Despite intensive investigation into the etiology of KD, this remains unclear, although monocytes and macrophages are thought to play an important role. We examined peripheral blood monocytes using a monoclonal antibody, PM-2K, which recognizes mature macrophages but not monocytes. This study was conducted in 12 patients with KD, three patients with sepsis and 12 control subjects. Approximately 8% of whole peripheral blood monocytes from patients with acute KD were observed to be PM-2K positive. Approximately 15-20% of peripheral blood CD14+ monocytes from these patients were positive for PM-2K antibody (as determined by immunoelectron microscopy). PM-2K-positive monocytes had significantly fewer numbers of intracytoplasmic peroxidase-positive granules than monocytes from control subjects. In contrast, PM-2K-negative monocytes from patients with acute KD had a significantly greater number of peroxidase-positive granules in the cytoplasm than in those from controls. Monocytes from patients with sepsis displayed PM-2K immunocytochemical staining, similar to that in monocytes from patients with KD. These results suggest that during the acute stage of KD, monocytes partly differentiate into macrophages in the peripheral circulation.

Increased frequency of alleles associated with elevated tumor necrosis factor-alpha levels in children with Kawasaki disease

Genetic polymorphisms influence the magnitude of the cytokine response after an inflammatory stimulus. To determine whether such polymorphisms might play a role in Kawasaki disease (KD), we analyzed white and Japanese children with KD and control populations for two polymorphic loci in which the A allele is associated with high tumor necrosis factor-alpha secretion. The lymphotoxin-alpha+250 A/A genotype was overrepresented among white children with KD compared with controls (0.59 versus 0.36; p = 0.013). The tumor necrosis factor-alpha-308 A/G genotype was overrepresented among whites with KD who had coronary artery abnormalities compared with those with normal echocardiograms (0.36 versus 0.09; p = 0.044). No significant difference was seen at either locus between Japanese children with KD and Japanese controls. The increased frequency of the high secretor alleles in white children with KD suggests that these loci may be related to susceptibility to KD and to outcome after disease.

Characterization of the T-cell receptor V-beta repertoire in Kawasaki disease

Kawasaki disease (KD) is a paediatric multisystem necrotizing vasculitis constituting the most frequent cause of acquired heart disease in childhood. Conflicting data have been reported regarding expanded T-cell populations using particular T-cell receptor (TCR) beta-chain variable (BV) gene segments, suggesting either a superantigen- or a conventional antigen-mediated immune response in this disease. In order to further investigate the role of T lymphocytes, cells were stained with an extensive panel of 21 different TCRBV specific monoclonal antibodies (MoAbs) covering almost 70% of all T-cells. Flow cytometry was employed to analyse the expression of the TCRBV repertoire in the CD4+ and CD8+ subsets separately, and of activation markers, in freshly isolated peripheral blood lymphocytes of 25 Kawasaki disease patients during the acute and convalescent phases of the disease. No abnormal usage of any TCRBV family was found, neither acutely nor during convalescence, compared with a control group of healthy children. However, a significant increase in interleukin-2 receptor (IL-2R)-expressing T lymphocytes restricted to the CD4+ subset was observed in KD patients. Our data confirm a strong immune activation in KD that might be of importance in the pathogenesis of the disease.

Serum C-reactive protein levels in patients with Kawasaki disease: from the results of nation-wide surveys of Kawasaki disease in Japan

Thirteen nation-wide epidemiological surveys of Kawasaki disease have been carried out successively since 1970 in Japan. In the latest survey, questionnaires on serum C-reactive protein (CRP) levels of the patients were included to clarify whether serum CRP levels could be available for the diagnosis and prediction of prognosis. A questionnaire from and diagnostic guidelines for Kawasaki disease were sent to all paediatric departments of hospitals with 100 or more beds throughout Japan, and information including maximal serum CRP levels was obtained on patients with Kawasaki disease diagnosed during the 2-year period from January 1993 to December 1994. Of the 11458 patients diagnosed during the 2-year period, maximal serum CRP levels were reported in 11040 patients (96.4%). The values of maximal serum CRP were higher in the age groups < 6 months and > 2 years. The mean value and the distribution of serum CRP levels in-suspected cases were lowest among the three diagnostic categories and this difference among diagnostic categories was highly significant in the age groups 6 M-1 Y and 1-2 Y. The proportion of patients with cardiac sequelae increased with serum CRP levels in each age group. The mean value and the distribution of serum CRP levels of the patients with cardiac sequelae was higher than those without it and this difference between cardiac prognoses was outstanding in the age groups 6 M-1 Y and < 6 M. The Receiver/Response Operating Characteristic (ROC) curve for maximal serum CRP levels in Kawasaki disease revealed that accuracy of maximal serum CRP levels for prediction of cardiac sequelae was highest in the age group 6 M-1 Y. A large-scale observation and analysis of serum CRP levels of the patients with Kawasaki disease revealed age-dependent relationships among maximal serum CRP levels, diagnostic categories and prognosis. Serum CRP levels may be helpful for the prediction of prognosis with the consideration of age.

Endogenous nitric oxide production in Kawasaki disease

To evaluate in vivo nitric oxide production in Kawasaki disease (KD), urinary nitrite/nitrate (NOx) excretion was measured in 8 children with KD (age 1.1-2.7 years). Urinary NOx excretion was 0.66 +/- 0.22 mmol mmol-1 creatinine (mean +/- SD) in the 8 children with KD in the initial stages. The levels were significantly increased compared with those of 12 age-matched healthy control subjects (0.35 +/- 0.08 mmol mmol-1 creatinine). Urinary Nox excretion was serially determined in four patients. For each patient, there was a further rise in urinary NOx excretion from baseline levels coincident with the administration of intact-type gammaglobulin and aspirin. With clinical and laboratory improvement, however, urinary NOx excretion declined to the normal range. These findings suggest that endogenous nitric oxide production is enhanced in children with acute KD. Further studies are needed to clarify the role of nitric oxide in the pathogenesis and clinical course of KD.

Effects of immunoglobulin and gamma-interferon on the production of tumour necrosis factor-alpha and interleukin-1 beta by peripheral blood monocytes in the acute phase of Kawasaki disease

In order to study the in vitro effects of intact immunoglobulin (Ig) and gamma-interferon (INF-gamma) in patients with Kawasaki disease, the production of tumour necrosis factor-alpha (TNF-alpha) and interleukin-1 beta (IL-1 beta) was measured in peripheral blood monocytes (PBM) both before and after intravenous immunoglobulin (IVIG) therapy. Spontaneous production of TNF-alpha and IL-1 beta both before and after IVIG therapy was significantly higher than in healthy controls. Intact Ig enhanced in vitro the production of TNF-alpha and IL-1 beta both before and after IVIG therapy approximately 3-4 times as compared to the spontaneous production. INF-gamma did not affect the production of the two cytokines. Ig enhanced IL-1 beta mRNA expression in PBM of KD by 3-8 times more than that of spontaneous production.

The potential role of bacterial superantigens in the pathogenesis of Kawasaki syndrome

Kawasaki syndrome is an acute multisystem vasculitis of infancy and early childhood associated with high fever, mucocutaneous inflammation, and the development of coronary artery abnormalities. Despite the widely held belief that Kawasaki syndrome is an infectious disease, investigations have failed to identify a causal organism. Previous studies have demonstrated that this illness is associated with marked activation of monocyte/macrophages and the selective expansion of V beta 2-, less so, of V beta 8.1/8.2-expressing T cells in the peripheral blood from Kawasaki syndrome patients during the acute phase of their illness. These immunologic features are characteristic of diseases that are caused by bacterial toxins which act as superantigens. Staphylococcal enterotoxins and streptococcal exotoxins are prototypic superantigens which stimulate large populations of T cells expressing particular T-cell receptor beta-chain variable (V beta) gene segments. Using the V beta 2+ T-cell expansion as an "immunologic footprint" for a superantigen, we have extended these observations to the identification and isolation of a novel clone of toxic shock syndrome toxin-1-producing Staphylococcus aureus in the majority of patients with Kawasaki syndrome and streptococcal pyrogenic exotoxin B/streptococcal pyrogenic exotoxin C-producing streptococci in a minority of Kawasaki syndrome patients. Toxic shock syndrome toxin-1, streptococcal pyrogenic exotoxin B, and streptococcal pyrogenic exotoxin C are known to stimulate V beta 2+ T cells. These observations support the hypothesis that the activation of V beta 2+ T cells during the acute phase of Kawasaki syndrome is caused by bacterial superantigen(s).

Characterization of CD4+ T helper cells in patients with Kawasaki disease (KD): preferential production of tumour necrosis factor-alpha (TNF-alpha) by V beta 2- or V beta 8- CD4+ T helper cells

KD is an acute febrile illness in children characterized by coronary arteritis accompanied by aneurysm and thrombotic occlusion. The etiology of KD is unknown. It has been recently reported that KD is associated with the selective expansion of V beta 2+ and V beta 8.1+ T cells in peripheral blood lymphocytes (PBL), by studying the T cell receptor (TCR) repertoire of in vitro activated T cells. KD may therefore be caused by a superantigen [1-3]. To understand better the immunopathology of KD, we investigated TCR V beta 2 and V beta 8.1 expression on both the T cells of freshly isolated PBL and T cell clones (TCC) from patients with KD. Cytokine production by TCC was also studied. Blood samples were obtained from patients with acute (n = 20) and convalescent (n = 20) KD, age-matched children with non-infectious diseases (n = 18), and healthy adults (n = 20). Among these four groups, there were no significant differences in the percentages of either V beta 2+ or V beta 8.1+ T cells of freshly isolated PBL. The same was true for the CD4+ or CD8+ T cell subsets. One hundred and five TCC (98 CD3+ CD4+ CD8- and seven CD3+ CD4- CD8+) established from the affected skin, lymph node or PBL of six patients with KD were also negative for either V beta 2 or V beta 8.1 TCR. Sixty-eight of 105 TCC (65%) produced detectable levels (> 5 pg/ml) of TNF-alpha (6-1016 pg/ml), in the absence of any stimuli. In contrast, only 11 (10%) of 105 TCC or 7 (7%) of 97 TCC produced detectable levels of IL-2 or IL-6, respectively, in the absence of any stimuli. Stimulation with phytohaemagglutinin (PHA) and phorbol myristate acetate (PMA) induced most TCC to produce higher amounts of TNF-alpha, IL-2 and IL-6. These results suggest that CD4+ T helper cells expressing TCR-beta other than V beta 2 or V beta 8 receptor, primarily through TNF-alpha production, are involved in the immunopathology of KD.

Serum levels of p60 soluble tumor necrosis factor receptor during acute Kawasaki disease

To evaluate the role of tumor necrosis factor alpha (TNF-alpha) during acute Kawasaki disease, we measured p60 soluble tumor necrosis factor receptor (sT-NF-R) shedding into the circulation in 48 patients with acute Kawasaki disease, all of whom received intravenous infusions of gamma-globulin. Of the 48 patients, 5 had coronary artery lesions. Serum concentrations of p60 sTNF-R and TNF-alpha were measured by a sandwich enzyme immunoassay. Patients with Kawasaki disease had increased serum levels of p60 sTNF-R. We found a positive correlation between serum levels of p60 sTNF-R and levels of TNF alpha during acute Kawasaki disease. Moreover, patients with coronary artery lesions had higher levels of sTNF-R than did those without coronary artery lesions. Our findings indicate that p60 sTNF-R levels in serum may be useful for determining the severity of vascular damage during acute Kawasaki disease, and that patients with Kawasaki disease and high sTNF-R levels seem to be susceptible to coronary artery lesions even if they receive therapy with intravenous infusions of gamma-globulin.

Tumor necrosis factor and monocytes are released during hemorrhagic shock

Tumor necrosis factor (TNF) is a key mediator involved in many physiologic processes including immunity, inflammation, and metabolism. A relationship between TNF and hemorrhagic shock has not been clearly demonstrated. To help understand the role of TNF in hemorrhagic shock we developed a hemorrhagic shock model to measure TNF and monocyte levels during hemorrhage and resuscitation. Male Sprague-Dawley rats were anesthetized and subjected to a 50% blood loss (30 ml/kg) over 2 min and left in shock for 58 min. The animals were then resuscitated with two times blood loss (60 ml/kg) using lactated Ringers over 1 h. This model results in 75% mortality within 3 days (LD 75). Blood samples (2 ml) were obtained at intervals during shock and resuscitation, and assayed for TNF concentrations and white blood cell counts. Despite a marked fall in total leukocytes (24,600 pre-hemorrhage to 11,300 post-hemorrhage, P < 0.005), monocytes increased in percentage and in total count. Blood levels of TNF were initially undetectable but rose within 10 min after hemorrhage, peaked at 30 min after hemorrhage, and then became undetectable during resuscitation. In this model, macrophages and TNF are released into the circulation after hemorrhagic shock. TNF may play a role as a mediator in the pathophysiology of hemorrhagic shock.

Immunopathology and cytokine detection in the skin lesions of patients with Kawasaki disease

To investigate the pathogenesis of Kawasaki disease, we examined biopsy specimens from the skin lesions of 10 Japanese patients at the site of the polymorphous exanthem on the hip and at the site of an inoculation with BCG (bacillus Calmette-Gruérin) vaccine of two of them. Ten normal patients were also examined for control purposes. The histopathologic features of the skin lesions were characterized by extensive edema with dilation of the small blood vessels in the papillary dermis; the site of BCG vaccine inoculation showed much greater inflammatory change; neutrophil emigration was weak and most of the infiltrates were CD4+ T lymphocytes and CD13+ macrophages. The expression of the DR locus of human leukocyte antigen was detected not only on the epidermal keratinocyte surface but also on the walls of the small blood vessels and the infiltrating cells around these blood vessels. We also detected cytokines in the skin lesions: (1) interleukin-1 alpha and tumor necrosis factor alpha were strongly positive in all patients with acute Kawasaki disease, (2) interleukin-2 and interferon gamma were weakly or partially positive, (3) no cytokines were detected in the convalescent phase, and (4) the amounts of cytokines at the site of BCG vaccine inoculations were larger than those at the site of the polymorphous exanthem. These findings suggest that CD4+ T lymphocytes and CD13+ macrophages are activated and interleukin-1 alpha and tumor necrosis factor alpha may be involved in the pathogenesis of the inflammation of acute Kawasaki disease.

Increased levels of circulating intercellular adhesion molecule 1 in Kawasaki disease

OBJECTIVE

We investigated whether levels of intercellular adhesion molecule 1 (ICAM-1) antigen shed into the circulation increase during acute Kawasaki disease (KD). We also compared ICAM-1 levels in acute KD with those in anaphylactoid purpura (AP) and in measles.

METHODS

Serum ICAM-1 levels were measured by a double-determinant immunoassay using 2 monoclonal antibodies in the FAST (Falcon assay screening test) system. Serum levels of tumor necrosis factor alpha (TNF alpha) were measured by a specific and sensitive sandwich enzyme immunoassay.

RESULTS

Patients with KD, but not those with AP or measles, had increased levels of shed ICAM-1 antigen in serum samples obtained during acute stages. Moreover, during the acute stage, KD patients with coronary artery lesions (CAL) had still higher levels of shed ICAM-1 than did those without CAL. We found a positive correlation between serum levels of shed ICAM-1 and levels of TNF alpha during acute KD.

CONCLUSION

Our findings suggest that the serum ICAM-1 level is an important immunologic parameter for determining the severity of vascular damage during acute KD.

Tumor necrosis factor-alpha inhibitory activity in urine of Kawasaki disease

Recently it has been reported that naturally occurring inhibitors of tumor necrosis factor alpha (TNF-alpha) were demonstrated in urine of some acute febrile patients. We investigated whether TNF-alpha inhibitory activity in urine increases during acute Kawasaki disease (KD). TNF-alpha inhibitory activities in urine were measured by a cytotoxicity assay on the TNF-susceptible cell line L929. KD patients had increased TNF-alpha inhibitory activities in urine during the acute stage and returned to a normal range during the convalescent stage. Our results suggest that the TNF-alpha inhibitor in urine is part of the regulatory system of TNF-alpha, which might be responsible for vascular injury during acute KD.

Selective expansion of T cells expressing T-cell receptor variable regions V beta 2 and V beta 8 in Kawasaki disease

Kawasaki disease (KD) is an acute vasculitis complicated by the development of coronary artery abnormalities. The etiology of KD is unknown. Based on the observation that KD is associated with marked activation of T cells and monocyte/macrophages, we hypothesized that KD may be caused by a superantigen [e.g., a bacterial toxin that stimulates T cells expressing particular T-cell receptor beta chain variable (V beta) gene segments]. Peripheral blood T cells from patients in the acute and convalescent phases of KD and from various control groups were analyzed for T-cell receptor V beta gene expression by using a quantitative PCR technique and cytofluorographic analysis with available anti-V beta monoclonal antibodies. Patients with acute KD demonstrated significantly elevated levels of circulating V beta 2+ and V beta 8.1+ T cells compared to the other control groups. none of the other 20 V beta populations analyzed by quantitative PCR were found to be significantly elevated. Using flow cytometry, we confirmed a significant elevation of T cells reactive with anti-V beta 8.1 and the lack of change in several other V beta subsets--i.e. V beta 5.1, -5.2, -6.7, and -12. During the convalescence phase of KD, there was a reduction in the abnormal levels of V beta 2+ and V beta 8.1+ T cells. These observations suggest that KD may be caused by a superantigen and may provide insight into the nature of the etiologic agent.