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.

A new infant case of Nakajo-Nishimura syndrome with a genetic mutation in the immunoproteasome subunit: an overlapping entity with JMP and CANDLE syndrome related to PSMB8 mutations.

Nakajo-Nishimura syndrome (NNS) is a very rare hereditary autoinflammatory disorder that generally has its onset in infancy with pernio-like rashes and gradually develops into partial lipodystrophy. A distinct homozygous PSMB8 mutation encoding an immunoproteasome subunit has recently been identified as its genetic cause. Here, we report a new case of a patient with NNS who developed exudative erythemas on his face and extremities at 2 months of age, along with high fever, elevated serum hepatic aminotransferase levels and hepatosplenomegaly. Massive infiltration of inflammatory cells was observed histologically in the dermis and subcutis without apparent leukocytoclastic vasculitis. These symptoms improved with oral corticosteroids but recurred periodically, and a thin angular face with long clubbed fingers gradually developed. Identification of the PSMB8 mutation finalized the diagnosis of NNS at 5 years of age. Understanding a variety of clinicopathological features at the developmental stages is necessary to make an early diagnosis of NNS.

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.

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.

Cytotoxic T-lymphocyte-associated antigen 4 gene polymorphisms in Japanese children with infection-associated hemophagocytic lymphohistiocytosis.

OBJECTIVE: This study examined whether genetic polymorphisms in cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4), a negative regulator of T cells, are associated with infection-associated hemophagocytic lymphohistiocytosis (IHLH) in Japanese children. METHODS: We investigated the alleles of four polymorphisms in the CTLA-4 gene [-318CT, +49AG, CT60 and a dinucleotide repeat length polymorphism (AT)n] in 43 Japanese children with IHLH and 100 healthy Japanese controls. The hyper-polymorphic (AT)n alleles were divided into two types; the shortest allele (designated as AT(7)) and the longer alleles (designated as AT(>)(7)). RESULTS: A significant difference in the distribution of the (AT)n genotype was found between patients and controls (p = 0.028). Also, the frequency of the AT(>)(7) allele was significantly higher in the patients with IHLH than in the controls (p = 0.007). No significant linkage disequilibrium was found between each polymorphism. With regard to laboratory data, patients homozygous for the CTLA-4 AT(>)(7) allele showed significantly higher serum levels of lactate dehydrogenase and soluble interleukin-2 receptor than patients with the other alleles. CONCLUSION: These results suggest that CTLA-4 polymorphisms might play a role in the development of IHLH in Japanese children.

Clinical assessment of Mycoplasma pneumoniae-associated hemophagocytic lymphohistiocytosis.

BACKGROUND: Mycoplasma pneumoniae has been reported to be an etiologic pathogen of infection-associated hemophagocytic lymphohistiocytosis (HLH), but few case reports have been available to date. METHODS: The clinical features of four childhood cases of M. pneumoniae-associated hemophagocytic lymphohistiocytosis (Mp-HLH) were retrospectively assessed to obtain data that might be useful for early diagnosis and effective management. The previous English-language literature pertaining to Mp-HLH was also reviewed. RESULTS: The patients were two boys and two girls, aged between 1 and 11 years of age. One patient was demonstrated to have concurrent infection with rubella. All the patients had typical radiographic features of M. pneumoniae pneumonia, and one patient also had encephalopathy as a complication. All the children underwent bone marrow examination because of antibiotic-refractory fever, mild hepatosplenomegaly, cytopenia, hyperferritinemia and elevated levels of urine beta2-microglobulin. Cytopenia and hepatosplenomegaly in the present patients were relatively mild as compared to those in cases of other infection-associated HLH such as Epstein-Barr virus infection-associated HLH. Treatment with corticosteroids resulted in prompt and complete resolution in two cases, and i.v. high-dose gammaglobulin therapy achieved a complete response in another child. Spontaneous resolution under treatment with antibiotics alone was observed in one case. CONCLUSION: Although Mp-HLH is a rare complication of M. pneumoniae infection, it should always be considered in patients with antibiotic-refractory M. pneumoniae infections with cytopenia. Mp-HLH might be effectively treated by corticosteroids or high-dose gammaglobulin. To clarify the diverse clinical manifestations of M. pneumoniae infections, immunological interactions between M. pneumoniae and the host immune system should be further investigated.

Non-myeloablative allogenic peripheral blood stem cell transplantation in a patient with refractory osteosarcoma.

The prognosis of patients with relapsed osteosarcoma is dismal despite the use of intensive chemotherapy. We describe a patient with refractory osteosarcoma who underwent non-myeloablative peripheral blood stem cell transplantation (PBSCT) from an human leukocyte antigen (HLA)-identical sibling during a third complete remission. The patient suffered pulmonary relapse after the transplantation. Cyclosporin A withdrawal induced a graft-vs.-osteosarcoma effect and graft-vs.-host disease, but eventually the tumor progressed. Although our experience in this case suggested the presence of a graft-vs.-osteosarcoma effect during non-myeloablative allogenic PBSCT, this strategy might have limited value for refractory osteosarcoma with rapid growth kinetics.

Helicobacter pylori infection in children with chronic idiopathic thrombocytopenic purpura.

BACKGROUND: Recently a high prevalence of Helicobacter pylori infection has been reported in adult patients with chronic idiopathic thrombocytopenic purpura (cITP). Furthermore, after H. pylori eradication therapy in such patients, their platelet counts have been observed to increase, suggesting that H. pylori may be a causative agent of adult cITP. However, there have been only a few reports of children with cITP. The purpose of the present paper was to examine the association between H. pylori infection and cITP in Japanese children. METHODS: Helicobacter pylori stool antigens (HpSA) were measured and the prevalence of H. pylori infection was determined in 10 children with cITP. RESULTS: Helicobacter pylori infection was found in only two of the subjects. In a boy, the urea breath test (UBT) was also positive and the patient received eradication therapy using amoxicillin, clarithromycin, and lansoprazole for 1 week. The therapy was successful and the patient's platelet count increased. The response was maintained throughout more than 1 year of follow up. CONCLUSIONS: The prevalence of H. pylori infection in children with cITP is not high. However, the platelet count increased after eradication therapy in a boy with cITP. It is suggested that the eradication of H. pylori infection would be valuable in children, as well as in adults, with cITP.

Macrophage activation syndrome in children with systemic-onset juvenile chronic arthritis.

Macrophage activation syndrome (MAS) is a life-threatening complication in children with rheumatic diseases, particularly systemic-onset juvenile chronic arthritis (SOJCA). Because of the potential fatality of this condition, prompt recognition and immediate therapeutic intervention are important. This study assessed the clinical features of nine MAS events in five children with SOJCA. Nonremitting fever and decreased platelet and white blood cell counts led to a diagnosis of MAS. The urinary beta2-microglobulin (beta2MG) level was a sensitive indicator of MAS. Serum levels of beta2MG and soluble interleukin-2 receptor were also elevated. These biologic markers reflecting hyperactivated cellular immunity are useful indicators of MAS. Four children treated with cyclosporin A (CSP) achieved rapid and complete recovery, but one patient without CSP died due to rapidly progressive respiratory failure. All children treated with CSP responded quickly, and fever abated within 36 h of initiation of treatment. CSP should be added to first-line therapy of MAS.

Severe hypercalcemia in a child with acute nonlymphocytic leukemia: the role of parathyroid hormone-related protein and proinflammatory cytokines.

Among the hematological malignancies, hypercalcemia has often been reported in lymphoid malignancies such as multiple myeloma and adult T cell leukemia/lymphoma, but it has only rarely been described in acute nonlymphocytic leukemia. We describe here a 14-month-old girl with acute monocytic leukemia complicated by severe hypercalcemia (4.6 mmol/l) at presentation. A bone survey showed generalized bone resorption, but no localized osteolytic lesions. A search for the etiology of the hypercalcemia revealed that the serum levels of parathyroid hormone-related protein (PTHrP) and also proinflammatory cytokines with stimulatory effects on osteolytic bone resorption - TNF-alpha, IL-6 and M-CSF - were elevated. The patient achieved complete remission with induction chemotherapy, and the levels of PTHrP and the cytokines became normalized. In this case, PTHrP and cytokines might have acted cooperatively to exacerbate bone resorption, resulting in severe hypercalcemia.

A-20C angiotensinogen gene polymorphism and proteinuria in childhood IgA nephropathy.

We have previously reported that the TT genotype of the angiotensinogen gene and the ID/DD genotype of the angiotensin-converting enzyme gene are associated with increased severity of proteinuria in IgA nephropathy in Japanese children. Recently it was reported that polymorphism at -20 from adenine to cytosine in the angiotensinogen gene, increasing the level of this transcript, was associated with the progression of renal dysfunction in adult IgA nephropathy. We therefore investigated whether this polymorphism is involved in IgA nephropathy in Japanese children. We identified this polymorphism in 105 children with IgA nephropathy and 119 healthy adults using polymerase chain reaction/restriction fragment length polymorphism analysis. At the time of biopsy, all patients had normal blood pressure and renal function. There were no differences in the genotypes and allele frequencies of this polymorphism between patients with IgA nephropathy and controls. The number of patients with the AC/CC genotype showing heavy proteinuria (>or=1.0 g/day per m(2) body surface area) at biopsy was significantly higher than that with the AA genotype ( P=0.039, chi-squared test). The AC/CC genotype of this polymorphism may be associated with an increased severity of proteinuria, suggesting that this polymorphism may play a significant role in the progression of IgA nephropathy in Japanese children.

Fatal pulmonary thromboembolism after a second course of high-dose chemotherapy with autologous peripheral blood stem cell transplantation.

We describe a 4-yr-old boy with an occult primitive neuroectodermal tumor, who suffered fatal PTE after a second course of HDC with autologous PBSCT. On day + 52 after a second PBSCT, he was admitted because of respiratory distress. Respiratory failure rapidly progressed and he died within 4 days. The diagnosis of PTE was confirmed by a lung perfusion study with technetium-99m macroaggregated albumin, but too late to allow treatment. Although rare, PTE must be recognized as an important differential diagnosis when respiratory symptoms are observed after HDC with PBSCT.