髙橋 和男

Cell-free and concentrated ascites reinfusion therapy (CART) by internal filtration pressure method (internal method) and external filtration pressure method (external method) using the same cancerous ascites was performed. The rate of rise in circuit pressure and recovered components were compared between the two methods. The factors related to circuit pressure rise were also researched. In both methods, circuit pressure rose in 50% of cases. The recovery rates of IgG, IgA, IgM, and haptoglobin were significantly higher for the internal method than for the external method, whereas the recovery rate of α1 -antitrypsin was significantly lower in the internal method than in the external method. The levels of IL-6, haptoglobin, α1 -antitrypsin, and fibrinogen/fibrindegradation products (FDP) in the original ascites were significantly higher in the group wherein circuit pressure rose than in that without circuit pressure rise. These proteins might be related to the rise in circuit pressure.

BACKGROUND: Few studies have focused on the association between history of ischemic stroke at predialysis stage and mortality after dialysis initiation. OBJECTIVE: To examine whether history of stroke in incident dialysis patients is associated with mortality, including all-cause and cardiovascular (CV)-related mortality. METHODS: The study database was derived from the Aichi Cohort Study of Prognosis in Patients Newly Initiated into Dialysis, a multicenter, prospective, cohort analysis. We classified patients into 2 groups according to their history of ischemic stroke and compared their outcomes. Propensity scores (PSs) represented the probability of being assigned to a group with or without a history of ischemic stroke. We defined the following outcomes: all-cause mortality; CV-related mortality; non-CV-related mortality; infection-related mortality; and stroke event after dialysis initiation. Factors contributing to the outcomes were examined using stepwise multivariate Cox proportional hazards analysis. RESULTS: All-cause mortality was significantly higher in the ischemic stroke group (log-rank test p < 0.001). All-cause, non-CV-related, and infection-related mortality and stroke event after dialysis initiation were significantly higher in the ischemic stroke group after PS matching (log-rank test: p < 0.001, <0.001, 0.002, and 0.002, respectively). History of ischemic stroke was associated with all-cause mortality in univariate analysis (hazard ratio [HR] 1.85, 95% CI 1.44-2.37). History of ischemic stroke before dialysis initiation was associated with all-cause mortality in multivariate analysis (HR 1.39, 95% CI 1.05-1.85). CONCLUSION: The present study revealed that history of ischemic stroke before dialysis initiation was associated with all-cause, non-CV-related, and infection-related mortality and stroke event after dialysis initiation during maintenance dialysis.

Some variables including age, comorbidity of diabetes, and so on at dialysis initiation are associated with patient prognosis. Cardiovascular (CV) events are a major cause of death, and adequate models that predict prognosis in dialysis patients are warranted. Therefore, we created models using some variables at dialysis initiation. We used a database of 1,520 consecutive dialysis patients (median age, 70 years; 492 women [32.4%]) from a multicenter prospective cohort study. We established the primary endpoint as a composite of the incidence of first CV events or all-cause death. A multivariable Cox proportional hazard regression model was used to construct a model. We considered a complex and a simple model. We used area under the receiver operating characteristic curve (AUROC) to assess and compare the predictive performances of the prediction models and evaluated the improvement in discrimination using the complex model versus the simple model using net reclassification improvement (NRI). We then assessed integrated discrimination improvement (IDI) to evaluate improvements in average sensitivity and specificity. Of 392 deaths, 152 were CV-related. Totally, 506 CV events occurred during the follow-up period (median 1,285 days). Finally, 692 patients reached the primary endpoint. Baseline data were set at dialysis initiation. AUROC for the primary endpoint was 0.737 (95% confidence interval [CI], 0.712-0.761) in the simple model and 0.765 (95% CI, 0.741-0.788) in the complex model. There were significant intergroup differences in NRI (0.44; 95% CI, 0.34-0.53; p < 0.001) and IDI (0.02; 95% CI, 0.02-0.03; p < 0.001). We prepared a Shiny R application for each model to automatically calculate the predicted occurrence probability (https://statacademy.shinyapps.io/App_inaguma_20190717/). The complex model made more accurate predictions than the simple model. However, the intergroup difference was not significant. Hence, the simple model was more useful than the complex model. The tool was useful in a real-world clinical setting because it required only routinely available variables. Moreover, we emphasized that the tool could predict the incidence of CV events or all-cause mortality for individual patients. In the future, we must confirm its external validity in other prospective cohorts.

The glomerulus primarily comprises mesangial cells, glomerular microvascular endothelial cells, and podocytes. IgA nephropathy is the most common primary glomerulonephritis worldwide and has a risk of progression to end-stage renal disease. IgA nephropathy is characterized by predominant IgA deposition in the glomerular mesangial area, where TG2 is significantly enhanced. Therefore, identification of glomerular TG2 substrates is the first step in elucidating the role of TG2 as a crosslinking enzyme during disease progression. To clarify potential glomerular TG2 substrates, and to establish a procedure for substrate identification, we attempted to identify those molecules using normal mouse glomeruli. Extracts from mouse glomerular and non-glomerular fractions were treated with our established biotin-labeled substrate peptide, which specifically crosslinks to the lysine-donor substrates depending on TG2 activity. Peptide-incorporated proteins were then purified using avidin resin and identified via mass spectrometry. In parallel, we performed the identification using corresponding samples from TG2 knockout mice. Consequently, potential TG2 substrates were separately identified in glomerular and non-glomerular fractions. They were mainly identified as novel TG2 substrates and partly include the well-known substrates. These results potentially provide novel insights into the mechanism underlying IgA nephropathy and may help elucidate the physiological functions of TG2.

BACKGROUND: Whether vitamin D receptor activator (VDRA) use is beneficial in chronic kidney disease (CKD) is unclear, because it is possible that VDRA increases serum fibroblast growth factor 23 (FGF23) levels. We will conduct a randomized controlled trial in predialysis patients to determine the effect of VDRA alone or in combination with lanthanum carbonate (LC) on serum FGF23 levels. METHODS: This is a single-center, open-label, randomized controlled trial. Enrollment will commence February 1, 2018, using the following inclusion criteria: (1) age ≥ 20 years, (2) CKD with an estimated glomerular filtration rate of 10-45 mL/min/1.73 m2, (3) serum adjusted calcium level < 9.5 mg/dL, (4) serum phosphate level 4.0-6.0 mg/dL, and (5) serum intact parathyroid hormone (PTH) level ≥ 60 pg/mL. Study patients will be randomized 1:1 to receive alfacalcidol alone or in combination with LC. The initial dose of alfacalcidol will be 0.25-0.5 µg once a day according to serum adjusted calcium level. The initial dose of LC will be 250 mg once a day. We will measure serum intact and C-terminal FGF23 at 0, 4, 8, 12, 24, and 52 weeks. The primary outcome will be serum FGF23 level at 24 weeks compared with baseline. DISCUSSION: This study aims to determine whether low-dose oral VDRA increases serum FGF23 level and whether the combination of VDRA and LC inhibits this increase. The results will be useful in the management of CKD-mineral and bone disorder in predialysis patients. TRIAL REGISTRATION: UMIN000030503. Registered 20 January 2018.

INTRODUCTION: An increasing number of patients worldwide require dialysis as a result of hypertensive nephrosclerosis (HTN). However, in Japan, mortality in patients with end-stage renal disease (ESRD) has not been well by primary kidney disease including HTN and diabetic nephropathy (DN). Hence, we examined the differences in mortality among the primary kidney diseases of incident dialysis patients. METHODS: The study was a multicenter prospective cohort analysis including 1520 incident dialysis patients in Aichi prefecture, Japan. We classified patients into three groups according to the primary kidney disease [i.e., a HTN group, n = 384, a DN group n = 658, and a chronic glomerulonephritis (CGN) group, n = 224]. In addition, we classified patients into the HTN group and the DN group using propensity score matching. We compared outcomes including all-cause and infection-related mortality. RESULTS: The mortality rates of the HTN, the DN, and the CGN group, were 135.9, 64.2, and 34.8 per 1000 patient years, respectively. All-cause mortality and infection-related mortality rates in the HTN group were as high as those in the DN group after adjustment for age, gender, history of cardiovascular disease, and estimated glomerular filtration rate. No significant difference of all-cause mortality was observed after propensity score matching between the two groups (Logrank test: p = 0.523). CONCLUSIONS: The present study was Japan's first large-scale prospective cohort to demonstrate that HTN is the second most common cause of ESRD. In addition, the prognosis of patients with HTN was as poor as that of patients with DN.

RATIONALE: Immunoglobulin G4 related disease (IgG4-RD) rarely coexists with other autoimmune diseases, though we had a patient whose primary clinical problem was shifted from IgG4-RD to systemic lupus erythematosus (SLE) after gastrectomy. The present paper aimed to report pathological findings and clinical course of the patient. PATIENT CONCERNS: The patient was a male aged 74 years old with gastric cancer characterized by the following symptoms: Raynaud phenomenon, polyarthralgia, and swollen parotid glands on both sides. Before gastrectomy, laboratory examination results showed renal dysfunction, hypocomplementemia, antinuclear antibodies (ANAs) positivity, and elevated serum IgG and IgG4 levels. DIAGNOSIS: Based on postoperative renal biopsy showing severe plasma cell infiltration with tubulointerstitial fibrosclerosis, the patient was diagnosed with IgG4-RD. Despite significant improvement in renal function and reduction in parotid gland swelling during the postoperative follow-up period, after 7 months of the gastrectomy, anti-DNA antibody levels were increased and serositis was detected, which indicated the onset of SLE. IgG4-type ANA were also detected in the sera of the patient. INTERVENTIONS: Treatment by oral prednisolone at 30 mg/day was initiated. OUTCOMES: Pericardial fluid, pleural effusions, and thickening of the gallbladder wall improved after 3 months of treatment according to computed tomography. LESSONS: This study presented a rare case of comorbidity, wherein the patient's primary problem progressed from IgG4-type ANA-positive IgG4-RD to SLE after excision of gastric cancer.

INTRODUCTION: As glomerular filtration rate (GFR) decreases, serum phosphate level increases. Previous reports indicated that serum phosphate level was associated with mortality in patients on dialysis. However, few reports have examined the association using dialysis initiation as the baseline period. METHODS: This was a multicenter prospective cohort analysis including 1492 patients. Patients were classified into four quartiles based on the serum phosphate level at dialysis initiation, with Q1 being the lowest and Q4 the highest. All-cause mortality after dialysis initiation was compared using the log-rank test. The propensity score represented the probability of being assigned to group Q1 or Q2-4. All-cause mortality was compared in propensity score-matched patients by using the log-rank test for Kaplan-Meier curves. All-cause mortality of Q1 was compared with that for Q2-4 using multivariate Cox proportional hazard regression analysis. All-cause mortality was also determined among stratified groups with or without use of phosphate binders. RESULTS: Significant differences in cumulative survival rates were observed between the four groups (p < .001). After propensity score-matching, mortality was significantly higher in the Q1 group than the Q2-4 group (p = .046). All-cause mortality was significantly higher in the Q1 group after adjustment for history of CAD (hazard ratio [HR] = 0.76, 95% confidence interval [CI]: 0.58 - 1.00, p = .048). However, there was no significant difference between the two groups after adjustment for estimated GFR. CONCLUSION: The serum phosphate level at the time of dialysis initiation was associated with all-cause mortality. However, the serum phosphate level was dependent on the renal function.

Extracellular histones induce lethal thrombosis by promoting platelet aggregation, neutrophil migration, and cell injuries. Heparin, which has negative charges, can bind to extracellular histones however, heparin strongly inhibits the activation of coagulation. Since chondroitin sulfate (CS) shows less effect on the coagulation system than heparin does, CS has the potential to become an effective drug for lethal thrombosis with high risk of bleeding. To elucidate the therapeutic mechanisms of CS in lethal thrombosis, we investigated the interaction between CS and extracellular histones. Mouse vascular endothelial cells were incubated with histones in the presence of heparin or CS, and the expression of caspase-3/7 was measured. The interactions between histones and heparin or CS were measured by surface plasmon resonance analysis. Vascular permeability, platelet counts, liver and renal functions, and coagulation times were evaluated in an in vivo assay. The apoptosis induced by histones was inhibited by treatment with heparin or CS. Heparin and CS showed strong binding to histones and inhibited vascular hyperpermeability. The platelet counts as well as liver and renal functions were not decreased by the treatment with heparin or CS. Moreover, CS showed less effect on the coagulation system than heparin did. These results suggested that CS can be a novel agent for lethal thrombosis with the risk for hemorrhage. Since vascular endothelial cell injuries occur at an early stage of lethal thrombosis, administration of CS might be a useful approach.

AIM: Some observational studies of the general population showed that resting heart rate was associated with mortality. However, the relationship was unclear in dialysis patients. METHODS: The study was a multicentre prospective cohort analysis including 1102 patients. Patients were classified into four groups based on resting heart rate just before starting the first dialysis session: <60/min; 60-79/min; 80-100/min; and ≥101/min. All-cause mortality, cardiovascular (CV) related mortality, and incidences of CV events after dialysis initiation were compared using the log-rank test. All-cause mortality rates for patients with heart rates <60, 60-79, and ≥101/min were compared to those for patients with heart rates 80-100/min, using multivariate Cox proportional hazard regression analysis. Moreover, we compared the outcomes among patients without use of β-blocker or heart failure symptom at the first dialysis session. RESULTS: Significant differences were observed in the all-cause mortality rates among the four groups (P = 0.007). Multivariate analysis revealed that all-cause mortality was significantly higher in patients with heart rate ≥ 101/min than in patients with heart rate 80-100/min (hazard ratio [HR] = 2.30, 95% confidence interval [CI]: 1.25-4.23). Subgroup analysis showed that among patients without use of b-blocker or heart failure symptom, all-cause mortality rates for those with heart rates ≥101/min were significantly higher than in patients with heart rate 80-100/min (HR = 2.98, 95% CI: 1.51-5.88, HR = 3.65, 95% CI: 1.59-8.36, respectively). CONCLUSION: The resting heart rate just before starting the first dialysis session was associated with all-cause mortality after dialysis initiation.

BACKGROUND: Aortic stenosis (AS) is common in patients on dialysis as well as in the general population. AS leads to difficulty with dialysis therapy because of unstable conditions such as intradialytic hypotension due to low cardiac output. However, the precise morbidity rates and risk factors of AS in patients on dialysis are unknown. Moreover, there are no large-scale observational studies regarding the association between AS in patients on dialysis and mortality. Therefore, we will investigate whether morbidity of AS in patients on dialysis is associated with mortality. METHODS: This is a multicenter prospective cohort analysis in the Tokai region of Japan. The 75 participating centers in this study will enroll approximately 2400 patients during 12 months, with or without AS. We started enrollment in July 2017 and will follow patents until June 2023. Transthoracic echocardiography will be performed to evaluate aortic valve. Parameters used for evaluation of aortic valve are mean pressure gradient between left ventricle and ascending aorta, aortic valve area, and maximum aortic jet velocity. We will diagnose AS using the criteria based on the 2014 American Heart Association/ American College of Cardiology Guideline. We will also perform transthoracic echocardiography at 12, 24, 36, 48, and 60 months. Survival prognosis and CV events will be determined at the end of June 2019, 2020, 2021, 2022, and 2023. Development of AS will be also evaluated as new onset or annual change in AS parameters. We will classify patients based on the presence or absence of AS and the stages of AS and will compare outcomes. Study outcomes will include the following: 1) all-cause mortality rates; 2) incidence of cardiovascular (CV) events; 3) CV-related mortality rates; 4) infection-related mortality rates; 5) new onset or development of AS. DISCUSSION: We will consider the following hypotheses in this study, among others: The prevalence of AS is higher in dialysis patients; new onset and development of AS are associated with factors that are specific for dialysis, such as hyperphosphatemia, hyperparathyroidism, and medication; and outcomes in AS patients are poorer than in patients without AS at baseline. TRIAL REGISTRATION: UMIN000026756 , Registered March 29 2017.

BACKGROUND: Some studies have shown that the estimated glomerular filtration rate (eGFR) at the time of initiating dialysis was associated with mortality. However, the relationship between ratio of blood urea nitrogen to serum creatinine (BUN/Cr) and mortality is unknown. METHODS: The study was a multicenter, prospective cohort analysis including 1520 patients. Patients were classified into four quartiles based on the BUN/Cr ratio at the dialysis initiation, with Q1 having the lowest ratio and Q4 the highest. All-cause mortality after initiating dialysis was compared using the log-rank test. All-cause mortality of Q1, Q2, and Q3 was compared with that of Q4 using multivariate Cox proportional hazard regression analysis. Moreover, we compared the renal parameters including BUN/Cr ratio, eGFR, and creatinine clearance for sensitivity and specificity using receiver operative characteristic (ROC) curve. RESULTS: Significant differences were observed in all-cause mortality among the four groups (p < 0.001). Multivariate analysis revealed that all-cause mortality was significantly higher in Q4 than in Q1 [hazard ratio (HR) = 1.82, 95% confidence interval (CI) 1.24-2.67, p = 0.002]. The increase in BUN/Cr ratio was positively associated with mortality (HR 1.04, 95% CI 1.02-1.06, p = 0.002). The sensitivity and specificity of BUN/Cr ratio for 180, 365, 730, and 1095 days mortality ranged between 0.60-0.72 and 0.59-0.71, respectively. The area under the curve of BUN/Cr for all-cause mortality was the highest among the renal parameters. CONCLUSION: The BUN/Cr ratio at the time of initiation of dialysis was associated with all-cause mortality.

Mannosylation in the endoplasmic reticulum is a key process for synthesizing various glycans. Guanosine diphosphate mannose (GDP-Man) and dolichol phosphate-mannose serve as donor substrates for mannosylation in mammals and are used in N-glycosylation, O-mannosylation, C-mannosylation, and the synthesis of glycosylphosphatidylinositol-anchor (GPI-anchor). Here, we report for the first time that low-abundant uridine diphosphate-mannose (UDP-Man), which can serve as potential donor substrate, exists in mammals. Liquid chromatography-mass spectrometry (LC-MS) analyses showed that mouse brain, especially hypothalamus and neocortex, contains higher concentrations of UDP-Man compared to other organs. In cultured human cell lines, addition of mannose in media increased UDP-Man concentrations in a dose-dependent manner. These findings indicate that in mammals the minor nucleotide sugar UDP-Man regulates glycosylation, especially mannosylation in specific organs or conditions.

Background: Several human studies reported that the combined use of renin-angiotensin system blockers (RASBs) and vitamin D receptor activators (VDRAs) resulted in decreased urinary protein excretion. However, it is unknown whether this combination therapy influences the incidence of cardiovascular (CV) events in dialysis patients. Methods: The study was a multicenter nonrandomized prospective cohort analysis including 1,518 patients. Patients were classified into 4 groups based on medications prescribed before dialysis initiation: those who did not receive RASBs or oral VDRAs (N group), those receiving only RASBs, those receiving only VDRAs, and those receiving a combination of RASBs and VDRAs (RD group). CV events after dialysis initiation were compared using the log-rank test. Factors contributing to the incidence of CV events were examined using multivariate Cox proportional hazard regression analysis. Results: Significant differences were observed in the incidence of CV events and all-cause mortality between the 4 groups (p = 0.021 and p = 0.001, respectively). Cox proportional hazard analysis revealed that the incidence of CV events was significantly lower in the RD group than in the N group (hazard ratio [HR] = 0.65, 95% confidence interval [CI]: 0.50-0.86, p = 0.002). Multivariate analysis revealed that the incidence of CV events was significantly lower in the RD group than in the N group (HR = 0.66, 95% CI: 0.47-0.93, p = 0.016). Conclusion: Combination therapy with RASBs and VDRAs in patients before dialysis initiation was associated with a reduction in CV events during maintenance dialysis.

BACKGROUND: Chronic kidney disease (CKD) is an independent risk factor for cardiovascular disease (CVD) events, and a number of reports have shown a relationship between CKD and CVD in pre-dialysis or maintenance dialysis patients. However, few studies have reported serial observations during dialysis initiation and maintenance. Therefore, we examined whether the incidence of heart disease events differed between CKD patients with and without a history of coronary heart disease (CHD) at dialysis initiation. METHODS: The subjects were patients in the 17 centers participating in the Aichi Cohort Study of Prognosis in Patients Newly Initiated into Dialysis (AICOPP) from October 2011 to September 2013. We excluded nine patients whose outcomes were unknown, as determined by a survey conducted at the end of March 2015. Thus, we enrolled 1,515 subjects into the study. We classified patients into 2 groups according to the history of CHD (i.e., a CHD group and a non-CHD group). Propensity scores (PS) represented the probability of being assigned to a group with or without a history of CHD. Onset of heart disease events and associated mortality and all-cause mortality were compared in PS-matched patients by using the log-rank test for Kaplan-Meier curves. Factors contributing to heart disease events were examined using stepwise multivariate Cox proportional hazards analysis. RESULTS: There were 254 patients in each group after PS-matching. During observation, heart disease events occurred in 85 patients (33.5%) in the CHD group and 48 (18.9%) patients in the non-CHD group. The incidence was significantly higher in the CHD group (p < 0.0001). The CHD group was associated with higher incidence of heart disease events (vs. the non-CHD group, hazard ratio = 1.750, 95% confidence interval = 1.160-2.639). In addition, comorbidities such as diabetes mellitus, low body mass index, and low serum high-density lipoprotein cholesterol were associated with higher incidence of events. CONCLUSION: History of CHD at dialysis initiation was associated with a higher incidence of heart disease events and mortality and all-cause mortality. TRIAL REGISTRATION: UMIN 000007096 . Registered 18 January 2012.

<p>Background: Cell-free and concentrated ascites reinfusion therapy (CART) was approved by the National Insurance Scheme in 1981 in Japan and has since been used as a treatment modality for refractory ascites. Two filtration methods may be used for CART: the internal and external pressure filtration methods. However, the precise characteristics of each method are unknown.</p><p>Methods: Ascitic fluid will be obtained by puncture from patients with refractory cancerous ascites. The quantity of fluid obtained from each patient will be divided in half, and each half will be processed using either the internal or external pressure filtration method. The primary endpoint will be the time required for the transmembrane pressure to reach 500 mmHg. The secondary endpoints will be serial changes in the weight of the ascitic and filtered fluid, serial changes in the pressure at the inlet and outlet of the filter, measurement of the components of the ascitic and filtered fluid, and observation of the filter by visual inspection and light and electron microscopy.</p><p>Conclusion: This trial may clarify the characteristics of the two filtration methods.</p><p>Trial registration: UMIN000025382.</p>

A major determinant in the change of the avian influenza virus host range to humans is the E627K substitution in the PB2 polymerase protein. However, the polymerase activity of avian influenza viruses with a single PB2-E627K mutation is still lower than that of seasonal human influenza viruses, implying that avian viruses require polymerase mutations in addition to PB2-627K for human adaptation. Here, we used a database search of H5N1 clade 2.2.1 virus sequences with the PB2-627K mutation to identify other polymerase adaptation mutations that have been selected in infected patients. Several of the mutations identified acted cooperatively with PB2-627K to increase viral growth in human airway epithelial cells and mouse lungs. These mutations were in multiple domains of the polymerase complex other than the PB2-627 domain, highlighting a complicated avian-to-human adaptation pathway of avian influenza viruses. Thus, H5N1 viruses could rapidly acquire multiple polymerase mutations that function cooperatively with PB2-627K in infected patients for optimal human adaptation.

In Japan, the Progressive Renal Dysfunction Research Group of the Ministry of Health, Labour and Welfare (MHLW) and the Japanese Society of Nephrology (JSN) developed the Clinical Practice Guides for Immunoglobulin A (IgA) Nephropathy (IgAN) for the first time in 1995. Thereafter, they published its second version in 2002 and third version in 2011. Meanwhile, the Kidney Disease: Improving Global Outcomes (KDIGO) published the Clinical Practice Guidelines for Glomerulonephritis in 2011. The Progressive Renal Dysfunction Research Group of MHLW and JSN developed the Clinical Practice Guidelines for Immunoglobulin A Nephropathy 2014 as an evidence-based guideline to make it more suitable for clinical practice in Japan. In this article, we describe the outlines of the Japanese guidelines and the differences between the Japanese and KDIGO guidelines. These practical guidelines provide evidence-based optimum treatment and will lead to new clinical trials raised from clinical questions in IgAN.

IgA nephropathy (IgAN), a frequent cause of end-stage renal disease, is an autoimmune disease wherein immune complexes consisting of IgA1 with galactose-deficient O-glycans (Gd-IgA1 autoantigen) and anti-glycan autoantibodies deposit in the glomeruli and induce renal injury. Serum IgA1 has three to six clustered O-glycans, some of which may be deficient in galactose and thus expose terminal or sialylated N-acetylgalactosamine. Patients with IgAN usually have elevated serum levels of Gd-IgA1. The mechanisms involved in production of Gd-IgA1 are not fully understood. Using IgA1-producing cell lines, we have analyzed the heterogeneity of IgA1 O-glycosylation and the corresponding biosynthetic pathways. IgA1 secreted by cells from IgAN patients vs. healthy controls had more galactose-deficient sites and overall more O-glycans. These changes were associated with differential expression/ activity of key glycosyltransferases in cells from patients with IgAN vs. controls, elevated for an initiating enzyme N-acetylgalactosaminyl (GalNAc)- transferase 14 and for GalNAc-specific sialyltransferase (ST6GalNAc-II) and, conversely, decreased for the galactosyltransferase (C1GalT1) and C1GalT1- associated chaperone Cosmc. Involvement of the key enzymes in the production of Gd-IgA1 was confirmed by siRNA knockdown and biochemical approaches. Moreover, expression of these enzymes is affected by some cytokines that further enhance the enzyme imbalance to increase Gd-IgA1 production. In summary, the production of Gd-IgA1, the key autoantigen in IgAN, by IgA1- secreting cells results from dysregulation of key glycosyltransferases and is augmented by certain cytokines. These findings provide insight into possible approaches for future disease-specific therapy.

Immunoglobulin A nephropathy (IgAN) is a worldwide disease characterized by the presence of galactose-deficient IgA1 deposits in the glomerular mesangium. A kidney biopsy for diagnosis is required. Here, we measured two miRNAs (let-7b and miR-148b), previously identified as regulators of the O-glycosylation process of IgA1, in serum samples from patients with IgAN and healthy blood donors (controls) recruited in an international multicenter study. Two predictive models, based on these miRNAs, were developed and the diagnostic accuracy of the combined biomarkers was assessed by the area under the receiver operating characteristic (ROC) curve (AUC) carried out in three steps. In a training study, the combined miRNAs were able to discriminate between 100 patients with IgAN and 119 controls (AUC, 0.82). A validation study confirmed the model in an independent cohort of 145 patients with IgAN and 64 controls (AUC, 0.78). Finally, in a test study, the combined biomarkers were able to discriminate patients with IgAN from 105 patients affected by other forms of primary glomerulonephritis, supporting the specificity (AUC, 0.76). Using the same study design, we also performed two subgroup analyses (one for Caucasians and one for East Asians) and found that race-specific models were the best fit to distinguish IgAN patients from controls. Thus, serum levels of the combined miRNA biomarker, let-7b and miR-148b, appears to be a novel, reliable, and noninvasive test to predict the probability of having IgAN.

Background The waiting time for deceased-donor kidney-only transplantations in Japan is long. Herein, we assessed the effect of length of dialysis on the outcomes of these patients. Methods We divided patients into 2 groups based on length of dialysis (Group A, &lt 15 years, and Group B, ≥15 years), and compared the background and outcomes after kidney transplantation. Results Group A included 210 patients and Group B included 35 patients. In Group B, 20% of transplants were from living donors. Patient age (P =.017) and the hepatitis C infection rate (P =.018) were significantly higher in Group B, whereas hypertension (P =.011), diabetes (P =.041), and ABO-incompatibility rates (P =.015) were significantly higher in Group A. The 5- and 10-year survival rates were 97.0% and 95.4%, respectively, in Group A and 97.1% and 97.1%, respectively, in Group B. The 5- and 10-year graft survival rates were 95.4% and 84.8%, respectively, in Group A and 97.1% and 73.1%, respectively, in Group B. There were no significant differences between the groups in patient survival (P =.74) and graft survival (P =.72). The 5- and 10-year cardiovascular event-free survival rates were 95.9% and 92.4%, respectively, in Group A and 88.6% and 76.8%, respectively, in Group B. Cardiovascular event-free survival was significantly higher in Group A (P =.038). Cox stepwise multivariate analysis indicated that length of dialysis was a significant predictor of cardiovascular events (hazard risk, 1.007 range, 1.001-1.012 P =.012). Conclusion The prognosis after kidney transplantation is promising even after a long length of dialysis, although evaluation of the cardiovascular risk is needed in these cases.

Anti-endothelial cell antibodies (AECA) are frequently detected in patients with systemic lupus erythematosus (SLE), but their pathological role remains unclear. We recently developed a solubilized cell surface protein capture enzyme-linked immunosorbent assay (CSP-ELISA) to detect antibodies against membrane proteins involved in autoimmune reactions. In this study, sera from 51 patients with biopsy-proven lupus nephritis (LN), 25 with SLE without renal involvement (non-LN SLE), 42 disease control (DC) subjects, and 80 healthy control (HC) subjects were tested for IgG- and IgA-AECA for human umbilical vein endothelial cells (HUVEC) and human glomerular EC (HGEC) by using CSP-ELISA. IgG- and IgA-AECA titers were significantly higher in LN and non-LN SLE patients than in the DC or HC (P < 0.001) groups. IgG- and IgA-AECA titers for HUVEC corresponded well with those for HGEC. The IgA-AECA level correlated with the SLE disease activity index and with histological evidence of active lesions (cellular proliferations, hyaline thrombi and wire loops, leukocytic infiltration, and fibrinoid necrosis) in LN patients (P < 0.001). The sensitivity of IgA-AECA as a diagnostic test for histological evidence of active lesions in LN patients was 0.92, with a specificity of 0.70. The significant correlation of IgA-AECA with glomerular hypercellularity indicates that IgA-AECA are associated with endothelial damage in LN.

OBJECTIVES: This study investigated the clinical course of myeloperoxidase-antineutrophil cytoplasm autoantibody (MPO-ANCA)-associated vasculitis after starting dialysis. METHODS: A retrospective review was conducted of the clinical charts of dialysis-dependent patients with MPO-ANCA-associated vasculitis who attended one of 8 associated clinics over the past 21 years. RESULTS: Eighty-nine patients were included in the study; 88 had microscopic polyangiitis (MPA) and 1 had granulomatosis with polyangiitis. Of the 88 patients with MPA, 18 had renal-limited vasculitis. Twenty-one relapses occurred among 13 patients (frequency, 0.05 relapses/person-year; 95% confidence interval, 0.03-0.08). Mean time from start of dialysis to relapse was 65 ± 59 months. Cox multivariate analysis showed that pulmonary involvement was a predictor of relapse (hazard ratio [HR], 21.4) and mortality (HR, 4.60), and that patient age (HR, 1.10) and cyclophosphamide use (HR, 0.20) were significant predictors of mortality. Postdialysis 1- and 5-year survival rates were 83.0% and 65.6%, respectively; infection was the most frequent cause of death. CONCLUSION: Pulmonary involvement was a predictor of relapse and mortality. Although relapse can occur long after the start of dialysis, incidence was low among dialysis-dependent patients. Prolonged maintenance immunosuppressive therapy might be limited to patients with pulmonary involvement in dialysis-dependent ANCA-associated vasculitis.

A 53-year-old woman who had undergone deceased donor kidney transplantation twice, at 35 and 43 years of age, presented with renal impairment. She was infected with hepatitis C virus (HCV). The histology of the graft kidney revealed post-transplant membranous nephropathy (MN) with podocytic infolding and antibody-mediated rejection (AMR). IgG subclass staining showed fine granular deposits of IgG1 and IgG3, but not IgG4, in the glomerular capillary walls. Panel reactive antibody scores for human leukocyte antigen class I and class II were 92.67% and 66.68%, respectively. Thus, this case of post-transplanted MN was considered to be associated with AMR and HCV infection.

BACKGROUND: Our aim was to assess plasma neutrophil gelatinase-associated lipocalin (NGAL) as a predictor of cardiovascular (CV) events in patients with chronic kidney disease (CKD) and no history of CV events. METHODS: This was a prospective observational cohort study of 252 patients with predialysis CKD. CV events were defined as CV death, acute coronary syndrome, and hospitalization for worsening heart failure, stroke, and aortic dissection. RESULTS: During a median follow-up period of 63 months, 36 CV events occurred. On Cox stepwise multivariate analysis, plasma NGAL and B-type natriuretic peptide (BNP) were significant predictors of CV events. Kaplan-Meier incidence rates of CV event-free survival at 5 years were 96.6%, 92.9%, 85.9%, and 61.3%, respectively, among quartiles of plasma NGAL (P < 0.0001). The C-index for the receiver-operating characteristic curves for CV events was greater when plasma NGAL was added to an established risk model (0.801, 95% CI 0.717-0.885), compared to the model without plasma NGAL (0.746, 95% CI 0.653-0.840, P = 0.021). CONCLUSION: Elevated plasma NGAL could predict future CV events in CKD patients with no history of CV events and add incremental value to the established risk model.

BACKGROUND AND AIMS: Cisplatin-induced nephrotoxicity primarily occurs in the proximal tubules, and tubular injuries reduce glomerular filtration rates. Lower blood pressure causes renal hypoperfusion, which promotes ischemic acute kidney injury (AKI). Our study examined the relationship between lower blood pressure-induced renal hypoperfusion and cisplatin-induced nephrotoxicity. METHODS: The relationship between cisplatin use and hypoalbuminemia is not clear. This study consisted of Japanese patients who received cisplatin as the first-line chemotherapy at Fujita Health University Hospital from April 2006 to December 2012. Hypoalbuminemia was defined as serum albumin levels ≤3.5 mg/dl. RESULTS: Patients who experienced lower blood pressure during chemotherapy were included in the lower blood pressure group (n = 229), and those who did not were included in the normal blood pressure group (n = 743). Total cisplatin dose in the normal blood pressure and lower blood pressure groups was 58.9 ± 23.8 and 55.0 ± 20.4 mg/m2, respectively. The rate of severe nephrotoxicity was higher and overall survival was shorter in the lower blood pressure group than in the normal blood pressure group. In a multivariable analysis, lower blood pressure significantly correlated with hypoalbuminemia. CONCLUSIONS: To prevent ischemic AKI, nutrition and cachexia controlling are important parts of cancer treatment.

Renal parenchymal lesions in patients with IgG4-related kidney disease (IgG4-RKD) are characterized by tubulointerstitial nephritis with storiform fibrosis and infiltration by high numbers of IgG4-positive plasma cells. The aim of this study was to evaluate the clinical and pathological effects of corticosteroid therapy in patients with IgG4-RKD. Of six patients who were diagnosed with IgG4-RKD, four patients underwent re-biopsy at approximately 30-50 days after corticosteroid therapy was initiated. Based on the classification of Yamaguchi et al., the degree of tubulointerstitial fibrosis was classified before and after therapy. In addition, tubulointerstitial expression patterns of α-smooth muscle actin (α-SMA), collagen I, III, and IV protein, and connective tissue growth factor (CTGF) mRNA were examined. Histopathological findings before treatment showed α-SMA-positive myofibroblasts in the lesion, and CTGF mRNA-positive cells were found in the cellular infiltrate. Although corticosteroid therapy improved serum creatinine clinically, the stage of fibrosis advanced pathologically as evidenced by increased staining for collagen I and III. However, the number of IgG4-positive plasma cells decreased, and CTGF mRNA expression reduced. In other words, fibrosis had advanced from the time of extensive cell infiltration in patients with IgG4-RKD and inflammation was relieved by corticosteroid. A reduced number of positive CTGF mRNA expression cells in repeat biopsies indicated that the fibrosis process was terminated by corticosteroid therapy. We propose that corticosteroid therapy could terminate the pathway of active fibrosis, thereby inhibiting progression to renal dysfunction.

BACKGROUND: IgA nephropathy, a frequent cause of end-stage renal disease, is an autoimmune disease wherein immune complexes consisting of IgA1 with galactose-deficient O-glycans (autoantigen) and anti-glycan autoantibodies deposit in glomeruli and induce renal injury. Multiple genetic loci associated with disease risk have been identified. The prevalence of risk alleles varies geographically, highest in eastern Asia and northern Europe, fewer in other parts of Europe and North America, and the least in Africa. IgA nephropathy is diagnosed from pathological assessment of a renal biopsy specimen. Currently, therapy is not disease-targeted but rather is focused on maintaining control of blood pressure and proteinuria, ideally with suppression of angiotensin II. Possible additional approaches differ between countries. Disease-specific therapy as well as new tools for diagnosis, prognosis, and assessment of responses to therapy are needed. SUMMARY: Glycosylation pathways associated with aberrant O-glycosylation of IgA1 and, thus, production of autoantigen, have been identified. Furthermore, unique characteristics of the autoantibodies in IgA nephropathy have been uncovered. Many of these biochemical features are shared by patients with IgA nephropathy and Henoch-Schönlein purpura nephritis, suggesting that the two diseases may represent opposite ends of a spectrum of a disease process. Understanding the molecular mechanisms involved in formation of pathogenic IgA1-containing immune complexes will enable development of disease-specific therapies as well as diagnostic and prognostic biomarkers. KEY MESSAGES: IgA nephropathy is an autoimmune disease caused by glomerular deposition of nephritogenic circulating immune complexes consisting of galactose-deficient IgA1 (autoantigen) bound by anti-glycan autoantibodies. A better understanding of the multi-step process of pathogenesis of IgA nephropathy and the genetic and environmental contributing factors will lead to development of biomarkers to identify patients with progressive disease who would benefit from a future disease-specific therapy.

Comparative studies of the potency of long- and short-acting erythropoiesis-stimulating agents (L-ESAs and S-ESAs) on erythropoietic activity in patients with chronic kidney disease without dialysis have not been performed, although L-ESAs are used in many countries. We performed a retrospective analysis of non-dialysis (ND) patients who had received L-ESA or S-ESA. More days were needed for the S-ESA-treated group (368 d) to reach the haemoglobin (Hb) reference range than for the L-ESA-treated group (126 d). Therefore, we investigated risk factors that influence the period until the Hb level reaches the reference range. Patients were classified into two groups by the period until the Hb level was stabilised within the reference range: the short- and long-term group. Two risk factors for delayed Hb stabilisation were identified: age ≥60 years and administration of an S-ESA for initial treatment. These findings suggest that the Hb level should be carefully monitored during ESA therapy in elderly ND patients, and that the ESA dose should be increased or L-ESA therapy should be utilised to treat renal anaemia.

Increased levels of hypo-galactosylated immunoglobulin (Ig)A1 (HG-IgA1) in IgA nephropathy (IgAN) have been detected using a Helix aspersa agglutinin lectin enzyme-linked immunosorbent assay (ELISA). In this study, we developed monoclonal antibodies to evaluate the HG-IgA1 in IgA nephropathy, aiming to gain a more consistent and reproducible assay. As an analogue to the HG-IgA1 hinge region, a 19 mer synthetic peptide with five GalNAc (sHGP) residues at positions 4, 7, 9, 11 and 15 [VPST(GalNAc)PPT(GalNAc)PS(GalNAc)PS(GalNAc)TPPT (GalNAc)PSPS-NH2] was synthesized. Two monoclonal antibodies against sHGP (35A12 and 44H8) that reacted with human IgA were developed. Also, their reactivities to serum IgA from IgAN patients (n = 49), patients with other forms of kidney diseases (OKD, n = 48), and healthy controls (HC, n = 41) were evaluated using ELISA assays. The binding levels of the two monoclonal antibodies against serum IgA were significantly higher (all comparisons, p < 0.0001, Steel-Dwass non-parametric test) in IgAN patients compared to HC and OKD patients. In each individual, there was a close correlation of IgA binding levels between 35A12 and 44H8 (R(2) = 0.737). These results indicate that the monoclonal antibodies recognize similar epitopes in HG IgA1, which is found predominantly in IgAN patients. The developed antibodies are proposed as a clinically useful tool for IgAN screening.

Chronic kidney disease (CKD) is associated with an increased risk of cardiovascular (CV) events. Recently, elevated neutrophil gelatinase-associated lipocalin (NGAL) levels have been reported in patients with heart failure, coronary heart disease, or stroke. Our aim was to assess urinary NGAL as a predictor of CV events in patients with CKD. This was a prospective observational cohort study of 404 patients with predialysis CKD. CV events were defined as CV death, acute coronary syndrome, hospitalization for worsening heart failure, stroke and dissection of aorta. During a mean follow-up period of 33 months, 77 CV events (19.1 %) occurred. After adjustment for gender, age, diabetes, previous cardiovascular disease, urinary albumin/creatinine ratio (UACR), estimated glomerular filtration rate, hemoglobin, and high-sensitivity C-reactive protein, patients with the other quartiles of urinary NGAL had significantly higher risk of CV events compared with patients with the lowest quartile (hazard ratio (HR) 2.81, 95 % confidence interval (CI) 1.01-7.81, P = 0.047 for Q2, HR 3.31, 95 % CI 1.22-9.00, P = 0.019 for Q3, and HR 3.27, 95 % CI 1.15-9.29, P = 0.026 for Q4). Regarding the combination of urinary NGAL with UACR, we also stratified patients into four groups according to whether the level of each marker was above or below the median (61.8 μg per gram creatinine (gCr) for NGAL and 351.1 mg/gCr for UACR). Four-year CV event-free survival rates were 89.2, 79.6, 71.8, and 51.5 % in order for the four respective groups (P < 0.0001). Elevated urinary NGAL was able to predict future CV events in CKD patients, and had incremental predictive value with elevated UACR.

BACKGROUND/AIM: To elucidate the mechanism responsible for developing acute kidney injury in patients with diabetes mellitus, we also evaluated the issue of whether advanced glycation endproducts (AGEs) influence the expressions of multi antimicrobial extrusion protein (MATE1/SLC47A1) in tubular cells. MATERIALS AND METHODS: To detect changing expression of MATE1/SLC47A1 in dose- and time-dependent manners, human proximal tubular epithelial cells were incubated with AGE-aggregated-human serum albumin. As a function assay for MATE1/SLC47A1, human proximal tubular epithelial cells were incubated with cisplatin or carboplatin. RESULTS: On incubation with AGEs, the expressions of MATE1/SLC47A1 were decreased in tubular cells. In addition, the toxicities of cisplatin were increased in tubular cells that had been pretreated with AGEs. However, the toxicities of carboplatin were smaller than that of cisplatin in proximal tubular epithelial cells. CONCLUSION: The expression of the MATE1/SLC47A1 is decreased by AGEs, which increases the risk for proximal tubular injury.

Background: Maintenance of low serum urate levels is important for the management of gout. Achieving the recommended serum urate levels of less than 6.0 mg/dL is difficult in elderly (65 years of age or older) patients with renal impairment. Xanthine oxidase inhibitors allopurinol and febuxostat are used for this purpose. Although febuxostat had been shown to be efficacious in elderly patients, its safety and efficacy in elderly female patients with hyperuricemia remain unclear. Objective: The aim of this study was to assess the efficacy and safety of febuxostat in elderly female patients. Methods: We studied a retrospective cohort study. The study included elderly Japanese patients (65 years of age or older) who were treated with febuxostat at Fujita Health University Hospital from January 2012 to December 2013. The treatment goal was defined as achievement of serum urate levels of 6.0 mg/dL or lower within 16 weeks; this was the primary endpoint in the present study. Adverse events of febuxostat were defined as more than twofold increases in Common Terminology Criteria for adverse events scores from baseline. Results: We evaluated 82 patients treated with febuxostat during the observation period and classified them into male (n=53) and female (n=29) groups. The mean time to achievement of the treatment goal was significantly shorter in the female group (53 days) than in the male group (71 days). There were no significant differences in adverse events between the 2 groups. Conclusion: Our findings suggest that the efficacy of febuxostat in elderly female patients is superior to that in elderly male patients and that the safety is equivalent.

Patients with IgA nephropathy (IgAN) have elevated circulating levels of IgA1 with some O-glycans consisting of galactose (Gal)-deficient N-acetylgalactosamine (GalNAc) with or without N-acetylneuraminic acid (NeuAc). We have analyzed O-glycosylation heterogeneity of naturally asialo-IgA1 (Ale) myeloma protein that mimics Gal-deficient IgA1 (Gd-IgA1) of patients with IgAN, except that IgA1 O-glycans of IgAN patients are frequently sialylated. Specifically, serum IgA1 of healthy controls has more α2,3-sialylated O-glycans (NeuAc attached to Gal) than α2,6-sialylated O-glycans (NeuAc attached to GalNAc). As IgA1-producing cells from IgAN patients have an increased activity of α2,6-sialyltransferase (ST6GalNAc), we hypothesize that such activity may promote premature sialylation of GalNAc and, thus, production of Gd-IgA1, as sialylation of GalNAc prevents subsequent Gal attachment. Distribution of NeuAc in IgA1 O-glycans may play an important role in the pathogenesis of IgAN. To better understand biological functions of NeuAc in IgA1, we established protocols for enzymatic sialylation leading to α2,3- or α2,6-sialylation of IgA1 O-glycans. Sialylation of Gal-deficient asialo-IgA1 (Ale) myeloma protein by an ST6GalNAc enzyme generated sialylated IgA1 that mimics the Gal-deficient IgA1 glycoforms in patients with IgAN, characterized by α2,6-sialylated Gal-deficient GalNAc. In contrast, sialylation of the same myeloma protein by an α2,3-sialyltransferase yielded IgA1 typical for healthy controls, characterized by α2,3-sialylated Gal. The GalNAc-specific lectin from Helix aspersa (HAA) is used to measure levels of Gd-IgA1. We assessed HAA binding to IgA1 sialylated at Gal or GalNAc. As expected, α2,6-sialylation of IgA1 markedly decreased reactivity with HAA. Notably, α2,3-sialylation also decreased reactivity with HAA. Neuraminidase treatment recovered the original HAA reactivity in both instances. These results suggest that binding of a GalNAc-specific lectin is modulated by sialylation of GalNAc as well as Gal in the clustered IgA1 O-glycans. Thus, enzymatic sialylation offers a useful model to test the role of NeuAc in reactivities of the clustered O-glycans with lectins.