Mondo Kuroda

Cytokine profiles of patients with enterohemorrhagic Escherichia coli O111-induced hemolytic-uremic syndrome

Proinflammatory cytokines are related to the pathogenesis of enterohemorrhagic Escherichia coli (EHEC) infection and hemolytic-uremic syndrome (HUS). We assessed the kinetics of the release of cytokines such as neopterin, interleukin (IL)-6, IL-8 and tumour necrosis factor (TNF)-α and the soluble forms of type I and II TNF receptors during EHEC O111-induced HUS (EHEC O111/HUS). Fourteen patients with EHEC O111/HUS were enrolled in this study. Serum concentrations of all cytokines other than TNF-α were significantly elevated in patients with severe HUS compared with those in patients with mild HUS. Although serum concentrations of TNF-α were not significantly higher in patients with severe HUS, most patients with acute encephalopathy showed elevated TNF-α levels. Serum concentrations of these cytokines rapidly and markedly increased, and massive hypercytokinaemia developed 1 day before the diagnosis of HUS in patients with severe HUS. Changes in the number of white blood cells and concentration of serum lactate dehydrogenase were significantly larger between the onset of hemorrhagic colitis and the time of the diagnosis of HUS in patients with severe HUS compared with those in patients with mild HUS. Proinflammatory cytokines play an important role in the pathogenesis of EHEC infection and development of severe complications, including HUS and encephalopathy. Monitoring the cytokine profile may be useful for assessing disease activity of EHEC O111 infections.

Expansion of activated eosinophils in infants with severe atopic dermatitis

Abstract  Background : There is increasing concern in Japan over infants with atopic dermatitis (AD) who present with severe systemic complications, such as hypoproteinemia, electrolyte disturbances, and delayed growth and development. They are often associated with extremely increased numbers of circulating eosinophils. However, the clinical significance of eosinophil expansion has not been thoroughly investigated.

Tolvaptan therapy for massive edema in a patient with nephrotic syndrome

BackgroundNephrotic syndrome (NS) is characterized by water and sodium retention, which leads to edema. The non-osmotic stimulation of arginine vasopressin release from the pituitary gland has been implicated as one of the important factors in abnormal water retention in patients with NS.Case-Diagnosis/TreatmentWe present the initial description of a patient with massive edema caused by refractory nephrotic syndrome, which was effectively treated with tolvaptan, a selective oral vasopressin V2 receptor antagonist.ConclusionsTolvaptan is effective for the treatment of massive edema caused by NS. Larger studies are needed in the future to fully assess the value and safety of tolvaptan use for this condition.

Extensive serum biomarker analysis in patients with enterohemorrhagic Escherichia coli O111-induced hemolytic-uremic syndrome

Proinflammatory cytokines are related to the pathogenesis of enterohemorrhagic Escherichia coli infection and hemolytic-uremic syndrome (HUS). We employed an antibody array that simultaneously detects 174 serum cytokines. We identified five serum biomarkers, namely insulin growth factor-binding protein-2, angiopoietin-2, soluble interleukin-6 receptor, soluble tumor necrosis factor receptor type II, and matrix metalloprotease protein-3 whose levels increased with the development of HUS. Furthermore, the levels of these cytokines were significantly increased in severe HUS compared with mild HUS. These cytokines might play an important role in the pathogenesis of HUS and may also be used to predict the severity of HUS.

Paternal uniparental isodisomy of chromosome 22 in a patient with metachromatic leukodystrophy

Metachromatic leukodystrophy (MLD) is an autosomal recessive lysosomal storage disease caused by deficiency of the enzyme arylsulfatase A encoded by the ARSA gene located on 22q13.33. Typically, in autosomal recessive disease, a patient inherits two mutations from both parents who are heterozygous carriers. However, in some instances, it is possible to develop the disease by uniparental isodisomy (UPiD), in which two copies of the same mutated allele are inherited from only one carrier parent. Here, we report the first patient with MLD caused by UPiD of chromosome 22. The patient has a homozygous missense mutation, P136T, on ARSA. Family study of the ARSA gene and leukocyte enzyme activity revealed that his father and sister were heterozygous carriers, but his mother possessed only wild-type alleles and normal enzyme activity. Karyotypes of the patient and the parents were normal. Microsatellite analysis showed no discrepancy of parentage, and paternal UPiD of chromosome 22 was indicated. Finally, genome-wide single-nucleotide polymorphism array confirmed the region of UPiD was extended to the entire chromosome 22 of the patient.

Serum tau protein as a marker of disease activity in enterohemorrhagic Escherichia coli O111-induced hemolytic uremic syndrome

Tau protein levels in cerebrospinal fluid (CSF) and serum are elevated in patients with various central nervous system diseases. We investigated whether serum tau protein levels are useful for predicting and assessing disease activity of acute encephalopathy (AE) in enterohemorrhagic Escherichia coli (EHEC) O111-induced hemolytic uremic syndrome (HUS; EHEC encephalopathy). Serum samples were obtained from 14 patients with EHEC O111/HUS, 20 patients with non-EHEC-related AE, and 20 age- and sex-matched healthy controls. CSF samples were obtained from 2 patients with EHEC encephalopathy and 20 patients with non-EHEC-related AE. Tau protein levels and levels of several proinflammatory cytokines were quantified by enzyme-linked immunosorbent assays. Results were compared with the clinical features of EHEC encephalopathy, including magnetic resonance image (MRI) findings. Serum tau levels in patients with EHEC encephalopathy were significantly elevated compared with those in patients with EHEC O111/HUS without encephalopathy, patients with non-EHEC-related AE, and healthy controls. The ratio of CSF tau levels to serum tau levels was >1.0 in all patients with non-EHEC-related AE but <1.0 in 2 patients with EHEC encephalopathy. Serum tau protein levels increased rapidly and markedly in patients with severe EHEC 0111/HUS and encephalopathy when HUS occurred, but were not elevated in mild patients, even in the HUS phase. Furthermore, changes in serum tau protein levels in patients with EHEC encephalopathy were consistent with abnormalities on brain MRI and were positively correlated with proinflammatory cytokine levels. Our results indicate that serum tau protein might be useful to predict and assess disease activity of EHEC encephalopathy.

Applying and testing the conveniently optimized enzyme mismatch cleavage method to clinical DNA diagnosis

Establishing a simple and effective mutation screening method is one of the most compelling problems with applying genetic diagnosis to clinical use. Because there is no reliable and inexpensive screening system, amplifying by PCR and performing direct sequencing of every coding exon is the gold standard strategy even today. However, this approach is expensive and time consuming, especially when gene size or sample number is large. Previously, we developed CEL nuclease mediated heteroduplex incision with polyacrylamide gel electrophoresis and silver staining (CHIPS) as an ideal simple mutation screening system constructed with only conventional apparatuses and commercially available reagents. In this study, we evaluated the utility of CHIPS technology for genetic diagnosis in clinical practice by applying this system to screening for the COL2A1, WRN and RPS6KA3 mutations in newly diagnosed patients with Stickler syndrome (autosomal dominant inheritance), Werner syndrome (autosomal recessive inheritance) and Coffin-Lowry syndrome (X-linked inheritance), respectively. In all three genes, CHIPS detected all DNA variations including disease causative mutations within a day. Direct sequencing of all coding exons of these genes confirmed 100% sensitivity and specificity. We demonstrate high sensitivity, high cost performance and reliability of this simple system, with compatibility to all inheritance modes. Because of its low technology, CHIPS is ready to use and potentially disseminate to any laboratories in the world.

A girl with infantile neuronal ceroid lipofuscinosis caused by novel PPT1 mutation and paternal uniparental isodisomy of chromosome 1

BACKGROUND Infantile neuronal ceroid lipofuscinosis (INCL) is an autosomal recessive disorder starting in infancy as early as 12-month-old, caused by PPT1 (palmitoyl-protein thioesterase 1) mutations, and characterized by progressive psychomotor deterioration, brain atrophy, myoclonic jerk and visual impairment. INCL can be diagnosed by brain magnetic resonance image (MRI) prior to rapid deterioration stage. To date, there is no INCL patient whose manifestation was caused by uniparental isodisomy (UPiD). PATIENT We reported a girl diagnosed with INCL. Genetic analysis revealed a novel PPT1 mutation c.20_47del28:p.Leu7Hisfs*21. Only the father of the patient was found as a carrier of this mutation. SNP array showed the mutation became homozygous by paternal UPiD of chromosome 1. DISCUSSION Although ICNL is a rare disease except in Finland, it is not difficult to diagnose it since the clinical symptoms and MRI findings are characteristic. Genetic testing is useful for definitive diagnosis, and distinction of UPiD is essential for genetic counseling.

Shiga toxin-2 enhances heat-shock-induced apoptotic cell death in cultured and primary glial cells.

The blood–brain barrier (BBB) selectively controls the homeostasis of the central nervous system (CNS) environment using specific structural and biochemical features of the endothelial cells, pericytes, and glial limitans. Glial cells, which represent the cellular components of the mature BBB, are the most numerous cells in the brain and are indispensable for neuronal functioning. We investigated the effects of Shiga toxin on glial cells in vitro. Shiga toxin failed to inhibit cell proliferation but attenuated expression of heat shock protein 70, which is one of the chaperone proteins, in cultured and primary glial cells. Furthermore, the combination of Shiga toxin and a heat shock procedure induced cell apoptosis and decreased cell proliferation in both cells. Thus, we speculate that glial cell death in response to the combination of Shiga toxin and heat shock might weaken the BBB and induce central nervous system complications.

Mutational analysis of TSC1 and TSC2 in Japanese patients with tuberous sclerosis complex revealed higher incidence of TSC1 patients than previously reported

Tuberous sclerosis complex (TSC) is an autosomal dominant disorder characterized by multiple hamartias and hamartomas involving throughout the body. To date, many TSC1 and TSC2 mutations have been reported all over the world, however, few TSC mutation studies have been performed in the Japanese population, and genetic characteristics of Japanese TSC patients are not yet clear. In this study, we analyzed TSC1 and TSC2 in 57 Japanese patients with TSC (8 familial and 49 sporadic; 46 definite and 11 suspect TSC) and identified 31 mutations including 11 TSC1 mutations (two familial and nine sporadic; all definite TSC) and 20 TSC2 mutations (2 familial and 18 sporadic; 19 definite and 1 suspect TSC). We also reviewed all Japanese TSC mutations previously reported. Our study demonstrates significantly higher incidence (P=0.007) of TSC1 mutations among sporadic TSC patients in the Japanese population compared with US and European studies. No differences emerged in mutation distributions and types in precedent studies, excepting low frequency of the TSC2 nonsense mutation. Comparing clinical manifestations, developmental delay and/or mental retardation were milder in TSC1 patients than TSC2 patients for its frequency (P=0.032) and severity (P=0.015); however, no other symptoms were clearly different.