Kawasaki disease: an overview:

Renal manifestations of systemic illness in children

Kidney disease may be associated with a systemic disorder or found in isolation. With advances in the understanding of the pathophysiology of glomerular disorders, the distinction between primary and secondary glomerular disease is no longer valid. A wide spectrum of glomerular, vascular, and tubulointerstitial diseases may accompany autoimmune disorders, nephritogenic pharmaceuticals, infections, or complement dysregulation. This article focuses on renal manifestations of systemic diseases such as vasculitis, drug- and infection-related tubulointerstitial injury, and thrombotic disorders.

Vasculitis in children

Primary systemic vasculitides of the young are relatively rare diseases, but can have a significant morbidity and mortality. The purpose of this review is to provide an overview of the paediatric vasculitides. Vasculitides that predominantly affect children will be considered in more detail than vasculitic diseases that although are seen in children affect adults more commonly, such as the ANCA associated vasculitides. New classification criteria for childhood vasculitis have recently been proposed and are currently undergoing validation. Epidemiological clues continue to implicate infectious triggers in Kawasaki Disease and Henoch Schönlein purpura. Several genetic polymorphisms have now been described in the vasculitides that may be relevant in terms of disease predisposition or development of disease complications. Treatment regimens continue to improve, with the use of different immunosuppressive medications and newer therapeutic approaches such as biologic agents. However new challenges are looming in regards to the role of inflammation in endothelial health and the long term cardiovascular morbidity for children with primary systemic vasculitis. International multicenter collaboration is of utmost importance in order for us to further advance our understanding and improve the treatment and outcome of systemic vasculitis in the young.

Infliximab reduces the cytokine-mediated inflammation but does not suppress cellular infiltration of the vessel wall in refractory Kawasaki disease

The aim of our study was to evaluate the efficacy of infliximab for the treatment of patients with refractory Kawasaki disease (KD) and investigate the dynamic changes of cytokines during infliximab treatment. We have performed a study of cytokine and proinflammatory molecule levels in 43 KD patients including 18 responders to IVIG, 14 nonresponders, and 11 patients treated with infliximab. We determined serum levels of soluble TNF receptor I (sTNFR I) and IL-6, as well as VEGF, damage associated molecular pattern (DAMP) molecules; myeloid-related protein (MRP)8/MRP14 and S100A12 sequentially. In eight patients, fever subsided immediately upon infliximab treatment. Four patients, who started infliximab after 12 d of illness, developed coronary artery lesions. Each of the cytokines was elevated before infliximab treatment in all patients. Although serum levels of proinflammatory cytokines decreased dramatically after infliximab treatment, DAMP molecules and VEGF and markers of local tissue damage were not suppressed. In contrast, in IVIG responders all cytokines decreased markedly after IVIG treatment. We show that infliximab is one of the adoptive therapies in refractory KD patients. Different behaviors of proinflammatory cytokines and DAMP molecules and VEGF after infliximab treatment suggest that infliximab is effective for suppression of cytokine-mediated inflammation, but could not completely block local vasculitis.

Early gene expression changes induced by the bacterial superantigen staphylococcal enterotoxin B and its modulation by a proteasome inhibitor

Toxic shock syndrome (TSS) is an acute, serious systemic illness caused by bacterial superantigens. Nonavailability of a suitable animal model until recently has hampered an in-depth understanding of the pathogenesis of TSS. In the current study, we characterized the early molecular events underlying TSS using our HLA-DR3 transgenic mouse model. Gene expression profiling using DNA microarrays identified a rapid and significant upregulation of several pro- as well as anti-inflammatory mediators, many of which have never been previously described in TSS. In vivo administration of staphylococcal enterotoxin B (SEB) led to an increase in the expression of Th0- (IL-2, 240-fold); Th1- (IFN-gamma, 360-fold; IL-12, 8-fold); Th2- (IL-4, 53-fold; IL-5, 4-fold) as well as Th17-type cytokines (IL-21, 19-fold; IL-17, 5-fold). The immunoregulatory cytokines (IL-6, 700-fold; IL-10, 18-fold); CC chemokines (such as CCL 2, 11, 3, 24, 17, 12, 7), CXC chemokines (such as CXCL 1, 2, 5, 11, 10, 19); and several proteases (matrix metalloproteinases 13, 8, 3, and 9) were also upregulated. Serum levels of several of these cytokines/chemokines were also significantly elevated. Pathway analyses revealed significant modulation in a variety of biochemical and cellular functions, providing molecular insights into the pathogenesis of TSS. Administration of bortezomib, a clinically approved proteasome inhibitor capable of blocking NF-kappaB pathway, was able to significantly modulate the expression of a variety of genes induced by SEB. Thus, our study showed that TSS is a complex process and emphasized the potential of use of bortezomib in the therapy of superantigen-induced TSS.