[Show abstract][Hide abstract] ABSTRACT: The Tohoku Medical Megabank Organization reports the whole-genome sequences of 1,070 healthy Japanese individuals and construction of a Japanese population reference panel (1KJPN). Here we identify through this high-coverage sequencing (32.4 × on average), 21.2 million, including 12 million novel, single-nucleotide variants (SNVs) at an estimated false discovery rate of <1.0%. This detailed analysis detected signatures for purifying selection on regulatory elements as well as coding regions. We also catalogue structural variants, including 3.4 million insertions and deletions, and 25,923 genic copy-number variants. The 1KJPN was effective for imputing genotypes of the Japanese population genome wide. These data demonstrate the value of high-coverage sequencing for constructing population-specific variant panels, which covers 99.0% SNVs of minor allele frequency ≥0.1%, and its value for identifying causal rare variants of complex human disease phenotypes in genetic association studies.
[Show abstract][Hide abstract] ABSTRACT: Residents of areas affected by the Great East Japan Earthquake may suffer from diseases or health problems. We are conducting a cross-sectional study from 2012 to 2015 to investigate and address the health needs of schoolchildren affected by this disaster. In this paper, we describe the protocol and research perspectives of our long-term child health study, and present the results obtained immediately after the disaster. The parent-administered questionnaire includes the International Study of Asthma and Allergies in Childhood questionnaire for asthma and eczema symptoms, the Strengths and Difficulties Questionnaire (SDQ), and a questionnaire on influenza infection and vaccination status. In 2012, we distributed the questionnaire to 3,505 (2(nd), 4(th), 6(th), and 8(th) graders) in three municipalities located in southern coastal area among the 28 municipalities, and 1,277 (36.4%) returned the completed questionnaire. Mean age was 11.1 ± 2.2 years old. The number of children with symptoms of wheeze and eczema in the past 12 months was 146 (11.4%) and 199 (15.6%), respectively. The SDQ total difficulties score revealed 174 (13.6%) children with some form of difficulty in their daily lives. From May 2011 to April 2012, 195 (15.3%) and 649 (50.8%) children received the influenza vaccination once and twice, respectively, and 532 (41.7%) had suffered from influenza. The prevalence of eczema symptoms or some form of difficulty was higher than the Japanese average. However, careful interpretation was required because of potential self-selection bias from the low response rate. We will continue this study of schoolchildren to provide aggregate findings.
The Tohoku Journal of Experimental Medicine 07/2015; 236(2):123-30. DOI:10.1620/tjem.236.123 · 1.35 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Leptospirosis is a zoonotic and disaster-related infectious disease. It is mainly endemic in subtropical or tropical countries and has not been reported since 2009 in the Tohoku region (northern Japan), including the Yamagata and Miyagi Prefectures. However, we experienced four patients with leptospirosis in the Tohoku region from 2012 to 2014; three patients (#1-3) live in the agricultural areas of the Yamagata Prefecture and one patient (#4) was a visitor to the Miyagi Prefecture. Patient 1 (81-year-old female) is a villager, with a rat bite, while Patient 2 (77-year-old male) and Patient 3 (84-year-old female) are farmers and were infected probably during agriculture work. Patient 4 (40-year-old male US citizen) was infected while traveling in Thailand. They had chief complaint of fever, headache, and myalgia and showed manifestations of hyperbilirubinemia (mean, 4.35 mg/dL), thrombocytopenia and acute kidney injury (AKI). All patients were diagnosed by polymerase chain reaction using blood and/or urine samples and a microscopic agglutination test for the anti-Leptospira antibody. All the patients were treated with infused antibiotics, including minocycline. The patients underwent hemodialysis due to severe AKI (mean serum creatinine, 4.44 mg/dL), except for Patient 2 with the normal serum creatinine level (1.12 mg/dL). All the patients recovered and were discharged. The presence of the three patients in the Yamagata Prefecture implies that leptospirosis does re-emerge in the Tohoku region. Therefore, careful survey of the pathogen is necessary for febrile patients with AKI who engage in agriculture or have a recent history of travelling in subtropical or tropical countries.
The Tohoku Journal of Experimental Medicine 05/2015; 236(1):33-7. DOI:10.1620/tjem.236.33 · 1.35 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Kidney International aims to inform the renal researcher and practicing nephrologists on all aspects of renal research. Clinical and basic renal research, commentaries, The Renal Consult, Nephrology sans Frontieres, minireviews, reviews, Nephrology Images, Journal Club. Published weekly online and twice a month in print.
Kidney International 05/2015; 87(5):1075-6. DOI:10.1038/ki.2015.47 · 8.56 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Juxtaglomerular apparatus (JGA) hyperplasia rarely happened in renal biopsy and has been controversial clinically, because synthesis and secretion of renin were susceptible to the effect of clinical condition and medication. Here we present the case of a 39-year-old who got JGA hyperplasia of IgA nephropathy (IgAN) after long-term inhibition of the renin-angiotensin system (RAS) with an angiotensin receptor blocker (ARB), and a direct renin inhibitor (DRI) in combination with a diuretic. He was diagnosed with IgAN in his first renal biopsy, and was treated with supra-maximal dosages of ARB, DRI and a diuretic. In the second biopsy, because of the massive proteinuria and occurrence of steroid-induced diabetes, it was revealed that the area and the number of JGA cells were strikingly increased in observed glomeruli. Immunohistopathologically, the both specimens were stained by human renin antibody. The hyperplastic JG cells contained a large amount of renin granules. Putative renin granules were observed in some interstitial cells adjacent to an afferent arteriole by electron microscopy. The increasing response of renin granules co-localized in prominent JGA hyperplasia should be worried while physicians treat hypertensive patients with potent RAS inhibitors and diuretics even though they have diabetes. This is the first report showing a clinical course of forming prominent JGA hyperplasia directly after a full combination of RAS inhibitors and diuretics in adult IgA nephropathy.
[Show abstract][Hide abstract] ABSTRACT: In recent times, therapy for renal anemia has changed dramatically in that iron administration has increased and doses of erythropoiesis-stimulating agents (ESAs) have decreased. Here we used a prospective, observational, multicenter design and measured the serum ferritin and hemoglobin levels every 3 months for 2 years in 1086 patients on maintenance hemodialysis therapy. The associations of adverse events with fluctuations in ferritin and hemoglobin levels and ESA and iron doses were measured using a Cox proportional hazards model for time-dependent variables. The risks of cerebrovascular and cardiovascular disease (CCVD), infection, and hospitalization were higher among patients who failed to maintain a target-range hemoglobin level and who exhibited high-amplitude fluctuations in hemoglobin compared with patients who maintained a target-range hemoglobin level. Patients with a higher compared with a lower ferritin level had an elevated risk of CCVD and infectious disease. Moreover, the risk of death was significantly higher among patients with high-amplitude ferritin fluctuations compared with those with a low ferritin level. The risks of CCVD, infection, and hospitalization were significantly higher among patients who were treated with high weekly doses of intravenous iron compared with no intravenous iron. Thus, there is a high risk of death and/or adverse events in patients with hemoglobin levels outside the target range, in those with high-amplitude hemoglobin fluctuations, in those with consistently high serum ferritin levels, and in those with high-amplitude ferritin fluctuations.Kidney International advance online publication, 23 April 2014; doi:10.1038/ki.2014.114.
Kidney International 04/2014; 86(4). DOI:10.1038/ki.2014.114 · 8.56 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The V2 receptor antagonist tolvaptan has been approved for volume control in heart-failure patients in Japan. Tolvaptan increases renal blood flow, and so the present study was designed to ascertain whether tolvaptan could be a useful diuretic for volume control without reducing residual renal function (RRF) in peritoneal dialysis (PD) patients. Tolvaptan was administered in 15 PD patients (15 mg daily). Urine volume, body weight, and blood pressure were monitored Urinary excretion of urea nitrogen Na+, the osmolality of plasma and urine, and peritoneal and renal Kt/V were analyzed before and after tolvaptan treatment. In 11 of 15 patients, urine volume increased to more than 400 mL daily. A significant increase in diluted urine was observed, as indicated by a reduction in the specific gravity or osmolality of urine (or both). Urinary excretion of urea nitrogen, and Na+ was significantly increased Increases in renal Kt/V were observed, but peritoneal Kt/V was unchanged. Singnificant increase in creatinine clearance was also observed These data suggest that tolvaptan not only stimulates water diuresis, but also natriuresis, without reducing RRF in PD patients. Hence, tolvaptan could be a beneficial tool for the control of body fluid and maintenance of RRF in PD patients.
Advances in peritoneal dialysis. Conference on Peritoneal Dialysis 12/2013; 29:33-7.
[Show abstract][Hide abstract] ABSTRACT: CKD progresses with fibrosis and erythropoietin (Epo)-dependent anemia, leading to increased cardiovascular complications, but the mechanisms linking Epo-dependent anemia and fibrosis remain unclear. Here, we show that the cellular phenotype of renal Epo-producing cells (REPs) alternates between a physiologic Epo-producing state and a pathologic fibrogenic state in response to microenvironmental signals. In a novel mouse model, unilateral ureteral obstruction-induced inflammatory milieu activated NFκB and Smad signaling pathways in REPs, rapidly repressed the Epo-producing potential of REPs, and led to myofibroblast transformation of these cells. Moreover, we developed a unique Cre-based cell-fate tracing method that marked current and/or previous Epo-producing cells and revealed that the majority of myofibroblasts are derived from REPs. Genetic induction of NFκB activity selectively in REPs resulted in myofibroblastic transformation, indicating that NFκB signaling elicits a phenotypic switch. Reversing the unilateral ureteral obstruction-induced inflammatory microenvironment restored the Epo-producing potential and the physiologic phenotype of REPs. This phenotypic reversion was accelerated by anti-inflammatory therapy. These findings demonstrate that REPs possess cellular plasticity, and suggest that the phenotypic transition of REPs to myofibroblasts, modulated by inflammatory molecules, underlies the connection between anemia and renal fibrosis in CKD.
Journal of the American Society of Nephrology 07/2013; 24(10). DOI:10.1681/ASN.2013010030 · 9.34 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Objective:
Macrophage (Mϕ) migration rests on the adhesion/detachment between Mϕ surface components and extracellular matrixes, and the contribution of numerous inflammatory disorders. Plasminogen activator inhibitor (PAI)-1, a serine protease inhibitor, influences Mϕ motility through an action distinct from its classical modulation of the plasmin-based fibrinolytic process. We rely here on a small molecule PAI-1 inhibitor (TM5275) to investigate the role of PAI-1 in Mϕ migration in the pathogenesis of renal injury.
Approach and results:
Mϕ migration was inhibited both in vitro and in vivo by TM5275. It was also reduced in T-cell-deficient nude mice, but not in PAI-1-deficient mice. Mϕ migration hinged on the interaction of PAI-1 with low-density lipoprotein receptor-related protein, an interaction prevented by TM5275, but not with vitronectin, urokinase-type plasminogen activator, or tissue-type plasminogen activator. Fed to rats with anti-Thy-1-induced nephritis, TM5275 significantly decreased Mϕ accumulation and ameliorated the progression of renal injury.
These findings suggest that a small molecule PAI-1 inhibitor represents a novel class of anti-inflammatory agents targeting Mϕ migration by the inhibition of the interaction of PAI-1 with low-density lipoprotein receptor-related protein.
[Show abstract][Hide abstract] ABSTRACT: The Japan Renal Biopsy Registry (J-RBR) was started in 2007 and the Japan Kidney Disease Registry (J-KDR) was then started in 2009 by the Committee for Standardization of Renal Pathological Diagnosis and the Committee for the Kidney Disease Registry of the Japanese Society of Nephrology. The purpose of this report is to describe and summarize the registered data from 2009 and 2010. For the J-KDR, data were collected from 4,016 cases, including 3,336 (83.1 %) by the J-RBR and 680 (16.9 %) other cases from 59 centers in 2009, and from 4,681 cases including 4,106 J-RBR cases (87.7 %) and 575 other cases (12.3 %) from 94 centers in 2010, including the affiliate hospitals. In the J-RBR, 3,165 native kidneys (94.9 %) and 171 renal grafts (5.1 %) and 3,869 native kidneys (94.2 %) and 237 renal grafts (5.8 %) were registered in 2009 and 2010, respectively. Patients younger than 20 years of age comprised 12.1 % of the registered cases, and those 65 years and over comprised 24.5 % of the cases with native kidneys in 2009 and 2010. The most common clinical diagnosis was chronic nephritic syndrome (55.4 % and 50.0 % in 2009 and 2010, respectively), followed by nephrotic syndrome (22.4 % and 27.0 %); the most frequent pathological diagnosis as classified by the pathogenesis was IgA nephropathy (31.6 % and 30.4 %), followed by primary glomerular diseases (except IgA nephropathy) (27.2 % and 28.1 %). Among the primary glomerular diseases (except IgA nephropathy) in the patients with nephrotic syndrome, membranous nephropathy was the most common histopathology in 2009 (40.3 %) and minor glomerular abnormalities (50.0 %) were the most common in 2010 in native kidneys in the J-RBR. Five new secondary and longitudinal research studies by the J-KDR were started in 2009 and one was started in 2010.
[Show abstract][Hide abstract] ABSTRACT: Background:
Excess fluid distribution is a common disorder in peritoneal dialysis (PD) patients. Tacrolimus malabsorption may also occur in PD patients, and may lead to acute allograft rejection after transplantation. The purpose of this study was to evaluate the relationship between tacrolimus pharmacokinetics and excess fluid distribution according to pre-transplant dialysis modality.
We retrospectively analyzed 41 adult living-donor kidney transplantations, including nine PD patients and 32 hemodialysis (HD) patients. We examined tacrolimus pharmacokinetics in the peri-operative period and determined the association between the tacrolimus absorption rate and body weight reduction. The absorption efficacy of tacrolimus was evaluated as the dose-normalized tacrolimus absorption rate. Tacrolimus concentrations in PD effluent were measured by high-performance liquid chromatography.
The tacrolimus absorption rate on the day before kidney transplantation tended to be lower in PD patients than in HD patients; however, the rate improved after kidney transplantation and was similar in both groups of patients. The peak tacrolimus concentration time was later in PD patients than in HD patients. The body weight reduction after kidney transplantation was greater in PD patients than in HD patients, and was significantly associated with the change in tacrolimus absorption rate (p=0.04, r=0.32). Only 0.002% of the oral tacrolimus dose was removed by PD itself.
Excess fluid distribution in PD patients appears to contribute to tacrolimus malabsorption rather than PD itself. We should consider the risk of tacrolimus malabsorption in patients with possible excess fluid distribution, particularly in PD patients.
[Show abstract][Hide abstract] ABSTRACT: Background and objectives:
Data regarding renal disease in the elderly (age ≥65 years old) and very elderly (age ≥80 years old) Japanese are extremely limited. The aim of this study was to examine the causes of renal disease and their clinical presentations in elderly patients who underwent renal biopsy.
Design, setting, participants, and measurements:
From July 2007 to November 2011, all of the elderly native renal biopsy patients who had been registered in the Japan Renal Biopsy Registry (J-RBR; 2802 including 1596 males and 1206 females) were identified. Their data were compared with a control group of 7416 patients who ranged in age from 20 to 64 years old and were registered on the J-RBR over the same period. In addition, the clinical and pathological classifications of 276 very elderly patients were also analyzed.
The indications for biopsy were nephrotic syndrome (NS) in 36.2 and 50.7 % of the elderly and the very elderly patients, chronic nephritic syndrome in 31.8 and 17.4 %, and acute kidney injury including rapidly progressive glomerulonephritis in 18.6 and 22.5 %, respectively. Primary glomerular disease was the most frequent diagnosis, followed by MPO-ANCA-positive nephritis, IgA nephropathy (IgAN), and diabetic nephropathy. In primary GN including IgAN, membranous nephropathy (MN) was the most frequent histological type, followed by IgAN and minor glomerular abnormalities. A comparison with the control group showed that MN, MPO-ANCA-positive nephritis, and amyloid nephropathy were more common in the elderly (P < 0.001), and IgAN was less common (P < 0.001). As for nephrotic syndrome in the elderly, MN was the most common histological type, followed by minimal change NS, diabetic nephropathy, amyloid nephropathy, and focal segmental glomerulosclerosis. There was a significant discrepancy between the urinary protein/creatinine ratio and daily proteinuria after the 7th decade of life.
Renal biopsy is a valuable diagnostic tool, even in elderly and very elderly Japanese patients. In the future, modified clinical guidelines for elderly renal disease should be developed.
[Show abstract][Hide abstract] ABSTRACT: Aim: Intrarenal vascular resistance estimated by resistive index (RI) is measured with renal duplex ultrasonography (RDU). Recently it has been reported that RI is useful to evaluate renal function of chronic kidney disease (CKD) and estimate prognosis of the kidney. As aortic blood flow is driving force of renal blood flow, they should be related each other. In the present study, we assessed relationships between aortic and intrarenal blood flow and CKD stages. Study Design: Cross-section study. Estimated GFR (mL/min/1.73m2) was calculated by modified MDRD formula by using serum creatinine level measured on closest day to each RDU date. We evaluated peak systolic velocity, end diastolic velocity and RI of sectional artery and interlobular artery, peak aortic velocity (PAV) and kidney size, which were compared with CKD stages. This study was permitted by medical ethics committee in Tohoku University. [Subject] CKD patients of 184 visiting our hypertension units in Tohoku university hospital during 2007 were examined in RDU. Patients with renovascular hypertension were excluded. [Results] Renal size from average longest diameter of each bilateral kidney was significantly correlated with CKD stages. Both RI on segmental and interlobular arteries were significantly correlated with CKD stages. PAV below the age of 40 is significantly faster than that above 40. PAV on CKD stage 1 is significantly faster than that on the other stages. Conclusion: RDU examination is available to evaluate renal remaining renal function. It notes that young patient tends to present higher PAV and higher intrarenal peak systolic velocity.
Journal of Hypertension 09/2012; 30:e211. DOI:10.1097/01.hjh.0000420404.67000.81 · 4.72 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Donor shortage is a serious problem worldwide and it is now debated whether kidneys from marginal donors are suitable for renal transplantation. Recent studies have shown that the findings of preimplantation kidney biopsy are useful to evaluate vasculopathy in the donated kidney, and may predict transplant outcomes in deceased- donor kidney transplantation. However, few studies have focused on the pathological findings of preimplantation biopsy in living-donor kidney transplantation. Therefore, we investigated whether arteriosclerotic vasculopathy in living-donor kidneys at the time of transplantation predicts the recipient's kidney function (allograft function) later in life.
We retrospectively analyzed 75 consecutive adult living-donor kidney transplants performed at Kagawa University Hospital. Renal arteriosclerotic vasculopathy was defined according to the presence of fibrous intimal thickening in the interlobular artery.
Forty-one kidneys exhibited mild arteriosclerotic vasculopathy on preimplantation kidney biopsies. The decreases in estimated glomerular filtration rate after donation were similar in donors with or without renal arteriosclerotic vasculopathy. Pre-existing arteriosclerotic vasculopathy did not affect graft survival rate, patient survival rate or the incidence of complications. Recipients of kidneys with arteriosclerotic vasculopathy had lower allograft function at 1 and 3 years after transplantation than the recipients of arteriosclerosis-free kidneys with or without donor hypertension. In multivariate analysis, fibrous intimal thickening on preimplantation biopsy was predictive of reduced allograft function at 1 year after transplantation.
The present study demonstrated that mild arteriosclerotic vasculopathy in the donated kidney is an important pathological factor that reflects future impaired function of renal allografts from marginal donors.
American Journal of Nephrology 07/2012; 36(2):127-35. DOI:10.1159/000340035 · 2.67 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Studies were performed to determine if early treatment with an angiotensin II (Ang II) receptor blocker (ARB), olmesartan, prevents the onset of microalbuminuria by attenuating glomerular podocyte injury in Otsuka Long-Evans Tokushima Fatty (OLETF) rats with type 2 diabetes mellitus.
OLETF rats were treated with either a vehicle, olmesartan (10 mg/kg/day) or a combination of nonspecific vasodilators (hydralazine 15 mg/kg/day, hydrochlorothiazide 6 mg/kg/day, and reserpine 0.3 mg/kg/day; HHR) from the age of 7-25 weeks.
OLETF rats were hypertensive and had microalbuminuria from 9 weeks of age. At 15 weeks, OLETF rats had higher Ang II levels in the kidney, larger glomerular desmin-staining areas (an index of podocyte injury), and lower gene expression of nephrin in juxtamedullary glomeruli, than nondiabetic Long-Evans Tokushima Otsuka (LETO) rats. At 25 weeks, OLETF rats showed overt albuminuria, and higher levels of Ang II in the kidney and larger glomerular desmin-staining areas in superficial and juxtamedullary glomeruli compared to LETO rats. Reductions in mRNA levels of nephrin were also observed in superficial and juxtamedullary glomeruli. Although olmesartan did not affect glucose metabolism, it decreased blood pressure and prevented the renal changes in OLETF rats. HHR treatment also reduced blood pressure, but did not affect the renal parameters.
This study demonstrated that podocyte injury occurs in juxtamedullary glomeruli prior to superficial glomeruli in type 2 diabetic rats with microalbuminuria. Early treatment with an ARB may prevent the onset of albuminuria through its protective effects on juxtamedullary glomerular podocytes.
American Journal of Hypertension 02/2012; 25(5):604-11. DOI:10.1038/ajh.2012.1 · 2.85 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The Great East Japan Earthquake (March 11, 2011), which caused unprecedented damage, also greatly affected dialysis facilities in Miyagi Prefecture. In particular, the coastal areas were devastated, affecting numerous chronic dialysis patients. The Supply of electricity and water was unstable, and communication links were paralyzed. The living conditions of the people were miserable. We requested dialysis facilities outside the disaster areas to provide treatment for chronic dialysis patients, because the quality of dialysis could not be maintained under the conditions. In regard to dialysis treatment, requesting the afflicted dialysis facilities to provide usual medical information about chronic dialysis patients does not fit into the basic philosophy of disaster relief. On the other hand, we had to treat many chronic dialysis patients who were admitted to our hospital for the first time. Issues related to the medical treatment of patients who were evacuated from the disaster-afflicted areas were quite different from those in ordinary situations. Therefore, we formulated a “clinical pathway for the hospitalization of chronic dialysis patients” as a tool to visualize information and allow it to be shared among different professionals and institutions. The clinical pathway allowed the standardization and understanding of patients conditions during hospitalization and was also helpful for the handover of patients to dialysis facilities in Hokkaido. The findings suggested that the clinical pathway would be a useful tool for chronic dialysis patients. We report the details in this article.