Tsutomu Saji

ITPKC functional polymorphism associated with Kawasaki disease susceptibility and formation of coronary artery aneurysms

Kawasaki disease is a pediatric systemic vasculitis of unknown etiology for which a genetic influence is suspected. We identified a functional SNP (itpkc_3) in the inositol 1,4,5-trisphosphate 3-kinase C (ITPKC) gene on chromosome 19q13.2 that is significantly associated with Kawasaki disease susceptibility and also with an increased risk of coronary artery lesions in both Japanese and US children. Transfection experiments showed that the C allele of itpkc_3 reduces splicing efficiency of the ITPKC mRNA. ITPKC acts as a negative regulator of T-cell activation through the Ca2+/NFAT signaling pathway, and the C allele may contribute to immune hyper-reactivity in Kawasaki disease. This finding provides new insights into the mechanisms of immune activation in Kawasaki disease and emphasizes the importance of activated T cells in the pathogenesis of this vasculitis.

Efficacy of immunoglobulin plus prednisolone for prevention of coronary artery abnormalities in severe Kawasaki disease (RAISE study): a randomised, open-label, blinded-endpoints trial

BACKGROUND Evidence indicates that corticosteroid therapy might be beneficial for the primary treatment of severe Kawasaki disease. We assessed whether addition of prednisolone to intravenous immunoglobulin with aspirin would reduce the incidence of coronary artery abnormalities in patients with severe Kawasaki disease. METHODS We did a multicentre, prospective, randomised, open-label, blinded-endpoints trial at 74 hospitals in Japan between Sept 29, 2008, and Dec 2, 2010. Patients with severe Kawasaki disease were randomly assigned by a minimisation method to receive either intravenous immunoglobulin (2 g/kg for 24 h and aspirin 30 mg/kg per day) or intravenous immunoglobulin plus prednisolone (the same intravenous immunoglobulin regimen as the intravenous immunoglobulin group plus prednisolone 2 mg/kg per day given over 15 days after concentrations of C-reactive protein normalised). Patients and treating physicians were unmasked to group allocation. The primary endpoint was incidence of coronary artery abnormalities during the study period. Analysis was by intention to treat. This trial is registered with the University Hospital Medical Information Network clinical trials registry, number UMIN000000940. FINDINGS We randomly assigned 125 patients to the intravenous immunoglobulin plus prednisolone group and 123 to the intravenous immunoglobulin group. Incidence of coronary artery abnormalities was significantly lower in the intravenous immunoglobulin plus prednisolone group than in the intravenous immunoglobulin group during the study period (four patients [3%] vs 28 patients [23%]; risk difference 0·20, 95% CI 0·12-0·28, p<0·0001). Serious adverse events were similar between both groups: two patients had high total cholesterol and one neutropenia in the intravenous immunoglobulin plus prednisolone group, and one had high total cholesterol and another non-occlusive thrombus in the intravenous immunoglobulin group. INTERPRETATION Addition of prednisolone to the standard regimen of intravenous immunoglobulin improves coronary artery outcomes in patients with severe Kawasaki disease in Japan. Further study of intensified primary treatment for this disease in a mixed ethnic population is warranted. FUNDING Japanese Ministry of Health, Labour and Welfare.

A genome-wide association study identifies three new risk loci for Kawasaki disease

We performed a genome-wide association study (GWAS) of Kawasaki disease in Japanese subjects using data from 428 individuals with Kawasaki disease (cases) and 3,379 controls genotyped at 473,803 SNPs. We validated the association results in two independent replication panels totaling 754 cases and 947 controls. We observed significant associations in the FAM167A-BLK region at 8p22-23 (rs2254546, P = 8.2 × 10−21), in the human leukocyte antigen (HLA) region at 6p21.3 (rs2857151, P = 4.6 × 10−11) and in the CD40 region at 20q13 (rs4813003, P = 4.8 × 10−8). We also replicated the association of a functional SNP of FCGR2A (rs1801274, P = 1.6 × 10−6) identified in a recently reported GWAS of Kawasaki disease. Our findings provide new insights into the pathogenesis and pathophysiology of Kawasaki disease.

Diagnosis, Treatment, and Long-Term Management of Kawasaki Disease: A Scientific Statement for Health Professionals From the American Heart Association.

Background: Kawasaki disease is an acute vasculitis of childhood that leads to coronary artery aneurysms in ≈25% of untreated cases. It has been reported worldwide and is the leading cause of acquired heart disease in children in developed countries. Methods and Results: To revise the previous American Heart Association guidelines, a multidisciplinary writing group of experts was convened to review and appraise available evidence and practice-based opinion, as well as to provide updated recommendations for diagnosis, treatment of the acute illness, and long-term management. Although the cause remains unknown, discussion sections highlight new insights into the epidemiology, genetics, pathogenesis, pathology, natural history, and long-term outcomes. Prompt diagnosis is essential, and an updated algorithm defines supplemental information to be used to assist the diagnosis when classic clinical criteria are incomplete. Although intravenous immune globulin is the mainstay of initial treatment, the role for additional primary therapy in selected patients is discussed. Approximately 10% to 20% of patients do not respond to initial intravenous immune globulin, and recommendations for additional therapies are provided. Careful initial management of evolving coronary artery abnormalities is essential, necessitating an increased frequency of assessments and escalation of thromboprophylaxis. Risk stratification for long-term management is based primarily on maximal coronary artery luminal dimensions, normalized as Z scores, and is calibrated to both past and current involvement. Patients with aneurysms require life-long and uninterrupted cardiology follow-up. Conclusions: These recommendations provide updated and best evidence-based guidance to healthcare providers who diagnose and manage Kawasaki disease, but clinical decision making should be individualized to specific patient circumstances.

A new nonsense mutation of SMAD8 associated with pulmonary arterial hypertension

Background: Pulmonary arterial hypertension (PAH) is a progressive disorder characterised by raised pulmonary artery pressures with pathological changes in small pulmonary arteries. Previous studies have shown that approximately 70% of familial PAH and also 11–40% of idiopathic PAH (IPAH) cases have mutations in the bone morphogenetic protein receptor type II (BMPR2) gene. In addition, mutations in the activin receptor-like kinase 1 (ALK1) gene have been reported in PAH patients. Since both the BMPR2 and ALK1 belonging to the transforming growth factor (TGF)-β superfamily are known to predispose to PAH, mutations in other genes of the TGF-β/BMP signalling pathways may also predispose to PAH. Methods: We screened for mutations in ENDOGLIN(ENG), SMAD1, SMAD2, SMAD3, SMAD4, SMAD5, SMAD6 and SMAD8 genes, which are involved in the TGF-β/BMP signallings, in 23 patients with IPAH who had no mutations in BMPR2 or ALK1. Results: A nonsense mutation in SMAD8 designated c.606 C>A, p.C202X was identified in one patient. The father of this patient was also identified as having the same mutation. Functional analysis showed the truncated form of the SMAD8 C202X protein was not phosphorylated by constitutively active ALK3 and ALK1. The SMAD8 mutant was also unable to interact with SMAD4. The response to BMP was analysed using promoter-reporter activities with SMAD4 and/or ca-ALK3. The transcriptional activation of the SMAD8 mutant was inefficient compared with the SMAD8 wild type. Conclusion: We describe the first mutation in SMAD8 in a patient with IPAH. Our findings suggest the involvement of SMAD8 in the pathogenesis of PAH.

Molecular and clinical study of 183 patients with conotruncal anomaly face syndrome

To investigate molecular and clinical aspects of conotruncal anomaly face (CAF), we studied the correlation between deletion size and phenotype and the mode of inheritance in 183 conotruncal anomaly face syndrome (CAFS) patients. Hemizygosity for a region of 22q11.2 was found in 180 (98%) of the patients with CAFS by fluorescence in situ hybridization (FISH) using the N25(D22S75) DiGeorge critical region (DGCR) probe. No hemizygosity was found in three (2%) of the patients with CAFS by FISH using nine DiGeorge critical region probes and a SD10P1 probe (DGA II locus). None of these three patients had mental retardation and just one had nasal intonation, which was observed in almost all of the 180 CAFS patients who carried deletions (mental retardation, 92%; nasal voice, 88%). Nineteen of 143 families (13%) had familial CAFS and 16 affected parents (84%) were mothers. Although only two of the affected parents had cardiovascular anomalies, the deletion size in the 16 affected parents and their affected family members, who were studied by FISH analysis, was the same. It indicates that extragenic factors may play a role in the genesis of phenotypic variability, especially in patients with cardiovascular anomalies. No familial cases were found among CAFS patients with absent thymus/DiGeorge anomaly (DGA). Also, in all 18 CAFS patients with completely absent thymus/DGA and all 6 CAFS patients with schizophrenia, it was revealed that the deletion was longer distally. A study of the origin of the deletion using microsatellite analyses in 48 de novo patients showed that in 65% of CAFS patients it was maternal, while in 64% of DGA patients it was paternal. The findings of this study indicated that CAF was almost always associated with the deletion of 22q11.2. As well as the major features of the syndrome, other notable extracardiac anomalies were found to be susceptibility to infection, schizophrenia, atrophy or dysmorphism of the brain, thrombocytopenia, short stature, facial palsy, anal atresia, and mild limb abnormalities.

Short-term hemodynamic effect of a new oral PGI2 analogue, Beraprost, in primary and secondary pulmonary hypertension

In 4 patients with primary pulmonary hypertension, there was a -24% +/- 20% decrease in pulmonary vascular resistance, a significant increase of cardiac index by +27 +/- 14% in all 4 patients; a -15 +/- 12% decrease in pulmonary artery pressure in 3 patients; and in 3 patients with 12% secondary pulmonary hypertension, there was a -24 +/- 14% decrease in pulmonary vascular resistance. Beraprost appears to be effective as a new pulmonary vasodilative agent.

Clinical and molecular analysis of Mowat-Wilson syndrome associated with ZFHX1B mutations and deletions at 2q22–q24.1

Hirschsprung disease (HSCR), a clinically complex syndrome often associated with a combination of mental retardation, microcephaly, and characteristic facial features, is genetically heterogeneous.1–10 Recently, mutations in ZFHX1B , which encodes Smad-interacting protein 1 (SIP1), were identified by our group11 and Cacheux et al 12 in patients with t(2;13)(q22;q22) and t(2;11)(q22.2;q21), respectively. These patients had clinical profiles consistent with a dominant form of the disease (Mowat-Wilson syndrome: MIM 235730).9,13 These and subsequent articles have demonstrated a link between patients with nonsense and frameshift mutations of the gene and the presence in these patients of the following clinical findings: profound mental retardation, delayed motor development, and specific facial features, including hypertelorism, a broad nasal bridge, strabismus, a pointed chin, prognathism, a nose with a prominent columella, and posteriorly rotated ears. Often associated with these features were microcephaly, epilepsy, congenital heart disease, HSCR, and midline defects such as agenesis or hypoplasia of the corpus callosum and hypospadias.13–19 This variety of clinical features is observed not only in patients with nonsense and frameshift mutations but also in patients harbouring deletions involving ZFHX1B at 2q22,9,11,15,20 including a previously reported isolated case.6 Thus, ZFHX1B clearly plays a critical role in the manifestation of clinical features of Mowat-Wilson syndrome. However, several points remain to be elucidated: (1) How broad are the clinical features in patients with ZFHX1B mutations and deletions? (2) What are the underlying molecular mechanisms by which the deletion of ZFHX1B at 2q22 affects the clinical phenotype? (3) What kind of clinical features might appear if the deletions were extended to include 2q23–q24.1? To address these questions, we have characterized the clinical features and underlying molecular basis of 27 cases with mutations or deletions in ZFHX1B , including 12 previously reported cases comprising …

Guidelines for diagnosis and management of cardiovascular sequelae in Kawasaki disease

Over 35 years have elapsed since the first case of Kawasaki disease was described in 1967. 1 As they grow older, many patients with a history of Kawasaki disease are treated in departments of internal medicine rather than in pediatric departments. This disease has been extensively studied throughout the world, and many reports have been published on its etiology and cardiovascular sequelae. While the causes of Kawasaki disease unfortunately remain unknown, its cardiovascular sequelae have been intensively studied, contributing to the establishment of their pathology, natural history, diagnosis, and treatment. This provided the impetus for the Japanese Circulation Society to prepare a set of guidelines. The latest guidelines for the diagnosis of Kawasaki disease, as revised in 2002, are shown in Table 1. These are used to diagnose the disease in its acute phase. The diagnostic guidelines may be useful in adults with an unknown history of Kawasaki disease when the illness is suspected from the morphology of any coronary artery aneurysms. In preparing the present guidelines for the cardiovascular sequelae of Kawasaki disease, the first issue addressed was the classification of the size and severity of coronary artery aneurysms using standardized criteria. The consensus criteria shown in Table 2 were prepared according to the conventional classification and the opinions of specialists.

CD40 ligand gene and Kawasaki disease.

Kawasaki disease (KD) is an acute systemic vasculitis syndrome of infants and young children. Although its etiology is largely unknown, epidemiological findings suggest that genetic factors play a role in the pathogenesis of KD. To identify genetic factors, affected sib-pair analysis has been performed. One of the identified peaks was located on the Xq26 region. A recent report of elevated expression of CD40 ligand (CD40L), which maps to Xq26, during the acute-phase KD, and its relationship to the development of coronary artery lesions (CAL) prompted us to screen for polymorphism of CD40L and to study the association of the gene to KD. A newly identified SNP in intron 4 (IVS4+121 A>G) is marginally over-represented in KD patients as compared to controls (109/602, 18.1 vs 111/737, 15.1%). When male KD patients with CAL were analyzed as a patient group, the SNP was significantly more frequent than in controls (15/58, 25.9%, vs 111/737, 15.1%, OR=2.0, 95% CI=1.07–3.66; P=0.030). Interestingly, this variation was extremely rare in a control Caucasian population (1/145, 0.7%). Our results suggest a role of CD40L in the pathogenesis of CAL and might explain the excess of males affected with KD.