Masakazu Miyawaki

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.

Cyclosporin A treatment for Kawasaki disease refractory to initial and additional intravenous immunoglobulin.

Background: There are still no definite treatments for refractory Kawasaki disease (KD). In this pilot study, we evaluated the use of cyclosporin A (CyA) treatment in patients with refractory KD. Methods: We prospectively collected clinical data of CyA treatment (4–8 mg/kg/d, oral administration) for refractory KD patients using the same protocol among several hospitals. Refractory KD is defined as the persistence or recurrence of fever (37.5°C or more of an axillary temperature) at the end of the second intravenous immunoglobulin (2 g/kg) following the initial one. Results: Subjects were enrolled out of 329 KD patients who were admitted to our 8 hospitals between January 2008 and June 2010. Among a total of 28 patients of refractory KD treated with CyA, 18 (64.3%) responded promptly to be afebrile within 3 days and had decreased C-reactive protein levels, the other 4 became afebrile within 4 to 5 days. However, 6 patients (21.4%) failed to become afebrile within 5 days after the start of CyA and/or high fever returned after becoming afebrile within 5 days. Although hyperkalemia developed in 9 patients at 3 to 7 days after the start of CyA treatment, there were no serious adverse effects such as arrhythmias. Four patients (1.2%), 2 before and the other 2 after the start of CyA treatment, developed coronary arterial lesions. Conclusion: CyA treatment is considered safe and well tolerated, and a promising option for patients with refractory KD. Further investigations will be needed to clarify optimal dose, safety, and timing of CyA treatment.

SAMD9 mutations cause a novel multisystem disorder, MIRAGE syndrome, and are associated with loss of chromosome 7

Adrenal hypoplasia is a rare, life-threatening congenital disorder. Here we define a new form of syndromic adrenal hypoplasia, which we propose to term MIRAGE (myelodysplasia, infection, restriction of growth, adrenal hypoplasia, genital phenotypes, and enteropathy) syndrome. By exome sequencing and follow-up studies, we identified 11 patients with adrenal hypoplasia and common extra-adrenal features harboring mutations in SAMD9. Expression of the wild-type SAMD9 protein, a facilitator of endosome fusion, caused mild growth restriction in cultured cells, whereas expression of mutants caused profound growth inhibition. Patient-derived fibroblasts had restricted growth, decreased plasma membrane EGFR expression, increased size of early endosomes, and intracellular accumulation of giant vesicles carrying a late endosome marker. Of interest, two patients developed myelodysplasitc syndrome (MDS) that was accompanied by loss of the chromosome 7 carrying the SAMD9 mutation. Considering the potent growth-restricting activity of the SAMD9 mutants, the loss of chromosome 7 presumably occurred as an adaptation to the growth-restricting condition.

ITPKC and CASP3 polymorphisms and risks for IVIG unresponsiveness and coronary artery lesion formation in Kawasaki disease

Functional single-nucleotide polymorphisms (SNPs) in inositol 1,4,5-trisphosphate 3-kinase C (ITPKC) (rs28493229) and caspase-3 (CASP3) (rs113420705; formerly rs72689236) are associated with susceptibility to Kawasakis disease (KD). To evaluate the involvement of these 2 SNPs in the risk for intravenous immunoglobulin (IVIG) unresponsiveness, we investigated 204 Japanese KD patients who received a single IVIG dose of 2 g kg−1 (n=70) or 1 g kg−1 daily for 2 days (n=134). The susceptibility allele of both SNPs showed a trend of overrepresentation in IVIG non-responders and, in combined analysis of these SNPs, patients with at least 1 susceptible allele at both loci had a higher risk for IVIG unresponsiveness (P=0.0014). In 335 prospectively collected KD patients who were treated with IVIG (2 g kg−1), this 2-locus model showed a more significant association with resistance to initial and additional IVIG (P=0.011) compared with individual SNPs. We observed a significant association when all KD patients with coronary artery lesions were analyzed with the 2-locus model (P=0.0031). Our findings strongly suggest the existence of genetic factors affecting patients’ responses to treatment and the risk for cardiac complications, and provide clues toward understanding the pathophysiology of KD inflammation.

Serum levels of neutrophil activation cytokines in Kawasaki disease

Abstract Background : The aim of the present study was to investigate whether neutrophils are early effector cells for vascular endothelial damage in the acute phase of Kawasaki disease (KD) by examining serial changes in neutrophil counts and serum levels of neutrophil activation cytokines, such as granulocyte colony stimulating factor (G‐CSF) and interleukin (IL)‐8.

Inflammatory cytokine profiles during Cyclosporin treatment for immunoglobulin-resistant Kawasaki disease

BACKGROUND Kawasaki disease (KD) is an acute systemic vasculitis occurring in medium-sized arteries, especially coronary arteries. Patients with KD who fail to respond to standard therapy with intravenous immunoglobulin (IVIG) face a higher risk of developing coronary artery lesions. Cyclosporin A (CsA) is one treatment option for IVIG-resistant KD. However, the mechanism of its suppression of inflammation in patients with KD remains unknown. METHODS AND RESULTS We analyzed time-line profiles of multiple inflammatory cytokines in sera of 19 patients treated with CsA (4 mg/kg/day, p.o., 14 days) after additional IVIG. Trough concentration of CsA in blood was maintained between 60 and 200 ng/ml. We examined serum samples before, on day 7, and at the end (day 14) of CsA treatment. Assays were conducted using a Milliplex kit®. Fourteen patients responded to CsA and became afebrile within 5 days (Responders), although five patients were regarded as Non-responders. Serum transitional levels of IL-6 (p<0.001), sIL-2R (p<0.001), sTNFRII (p<0.001), and G-CSF (p<0.001) reflect disease severity. In Non-responders, average levels of IL-6 at day 7 (43.5 vs. 13.8 pg/ml, p<0.001) and average levels of sIL-2R at day 14 (21.3 vs. 3.31 pg/ml, p=0.014) were significantly higher than those in Responders. CONCLUSION CsA treatment effectively reduced the persisting serum inflammatory cytokines in most of the IVIG-resistant KD patients. Soluble IL-2R suppression implies a mechanism explaining the effects of CsA.

Plasma angiotensin II concentrations in the early neonatal period

Background: There have been only a few reports on the renin-angiotensin system in low birthweight infants; in particular, plasma angiotensin II concentrations have not been studied. Aim: To investigate plasma angiotensin II concentrations in early neonatal infants including low birthweight infants. Methods: Forty six patients were studied, of whom 14 weighed not less than 2500 g (normal birth weight), 16 weighed less than 2500 g but not less than 1500 g (moderately low birth weight), and 16 weighed less than 1500 g (very low birth weight). Blood samples were collected twice, on day 0 and day 7. Angiotensin II concentration was assayed using an enzyme immunoassay kit with a microplate. Results: Geometric means of angiotensin II concentrations on day 7 were 19 pg/ml in the normal birthweight group, 28 pg/ml in the moderately low birthweight group, and 76 pg/ml in the very low birthweight group. The concentrations on day 7 in the very low birthweight group were significantly higher than those in the normal birthweight and moderately low birthweight groups (p  =  0.005, p  =  0.031). There were significant correlations between angiotensin II concentration on day 7 and gestational age (rs  =  −0.4, p  =  0.007) and birth weight (rs  =  −0.36, p  =  0.016). Conclusions: Specific physiological conditions associated with a very low birth weight are thought to be responsible for the increased concentration of angiotensin II on day 7. It is necessary to measure angiotensin II concentration for a longer period after birth and study the factors that could influence it.

Variations in ORAI1 Gene Associated with Kawasaki Disease

Kawasaki disease (KD; MIM#61175) is a systemic vasculitis syndrome with unknown etiology which predominantly affects infants and children. Recent findings of susceptibility genes for KD suggest possible involvement of the Ca(2+)/NFAT pathway in the pathogenesis of KD. ORAI1 is a Ca(2+) release activated Ca(2+) (CRAC) channel mediating store-operated Ca(2+) entry (SOCE) on the plasma membrane. The gene for ORAI1 is located in chromosome 12q24 where a positive linkage signal was observed in our previous affected sib-pair study of KD. A common non-synonymous single nucleotide polymorphism located within exon 2 of ORAI1 (rs3741596) was significantly associated with KD (P = 0.028 in the discovery sample set (729 KD cases and 1,315 controls), P = 0.0056 in the replication sample set (1,813 KD cases vs. 1,097 controls) and P = 0.00041 in a meta-analysis by the Mantel-Haenszel method). Interestingly, frequency of the risk allele of rs3741596 is more than 20 times higher in Japanese compared to Europeans. We also found a rare 6 base-pair in-frame insertion variant associated with KD (rs141919534; 2,544 KD cases vs. 2,414 controls, P = 0.012). These data indicate that ORAI1 gene variations are associated with KD and may suggest the potential importance of the Ca(2+)/NFAT pathway in the pathogenesis of this disorder.

Rodriguez lethal acrofacial dysostosis syndrome with pulmonary hypoplasia

oncogene are associated with MEN 2A and FMTC. Hum. Mol. Genet. 1993; 2: 851–56. 4 Brandi ML, Gagel RF, Angeli A et al. Guidelines for diagnosis and therapy of MEN type 1 and type 2. J. Clin. Endocrinol. Metab. 2001; 86: 5658–71. 5 Sanso GE, Domene HM, Garcia R et al. Very early detection of RET proto-oncogene mutation is crucial for preventive thyroidectomy in multiple endocrine neoplasia type 2 children: Presence of C-cell malignant disease in asymptomatic carriers. Cancer 2002; 94: 323–30. 6 van Heurn LW, Schaap C, Sie G et al. Predictive DNA testing for multiple endocrine neoplasia 2: A therapeutic challenge of prophylactic thyroidectomy in very young children. J. Pediatr. Surg. 1999; 34: 568–71. 7 Wolfe HJ, Melvin KEW, Cevri-Skinner SJ et al. C-cell hyperplasia preceding medullary thyroid carcinoma. N. Engl. J. Med. 1973; 289: 437–41. 8 DeLellis RA. C-cell hyperplasia: A current perspective. Adv. Anat. Pathol. 1997; 4: 17–22. 9 Maeda S, Namba H, Takamura N et al. A single missense mutation in codon 918 of the RET proto-oncogene in sporadic medullary thyroid carcinomas. Endocr. J. 1995; 42: 245–50. 10 Pausova Z, Soliman E, Amizuka N et al. Role of the RET protooncogene in sporadic hyperparathyroidism and in hyperparathyroidism of multiple endocrine neoplasia type 2. J. Clin. Endocrinol. Metab. 1996; 81: 2711–18. 11 Skinner MA, DeBenedetti MK, Moley JF, Norton JA, Wells SA Jr. Medullary thyroid carcinoma in children with multiple endocrine neoplasia types 2A and 2B. J. Pediatr. Surg. 1996; 31: 177–82. 12 Hofstra RM, Landsvater RM, Ceccherini I et al. A mutation in the RET proto-oncogene associated with multiple endocrine neoplasia type 2B and sporadic medullary thyroid carcinoma. Nature 1994; 367: 375–76. 13 Eng C, Clayton D, Schuffenecker I et al. The relationship between specific RET proto-oncogene mutations and disease phenotype in multiple endocrine neoplasia type 2: International RET mutation consortium analysis. JAMA 1996; 276: 1575–79. 14 Eng C, Smith DP, Mulligan LM et al. Point mutation within the tyrosine kinase domain of the RET proto-oncogene in multiple endocrine neoplasia type 2B and related sporadic tumours. Hum. Mol. Genet. 1994; 3: 237–41. 15 Niccoli-Sire P, Murat A, Baudin E et al. Early or prophylactic thyroidectomy in MEN 2/FMTC gene carriers: Results in 71 thyroidectomized patients. The French Calcitonin Tumours Study Group (GETC). Eur. J. Endocrinol. 1999; 141: 468–74.

Clinical and functional characterization of the Pro1198Leu ABCC8 gene mutation associated with permanent neonatal diabetes mellitus

The adenosine triphosphate (ATP)‐sensitive potassium (KATP) channel is a key component of insulin secretion in pancreatic β‐cells. Activating mutations in ABCC8 encoding for the sulfonylurea receptor subunit of the KATP channel have been associated with the development of neonatal diabetes mellitus (NDM). The aim was to investigate clinical and functional characterization of the Pro1198Leu ABCC8 gene mutation associated with permanent NDM (PNDM).