More rapid progression of brain atrophy in patients on peritoneal dialysis compared with hemodialysis: The VCOHP Study

We previously reported that brain atrophy was more severe and progressed more rapidly in patients with end-stage kidney disease on peritoneal dialysis (PD) than those with non-dialysis-dependent chronic kidney disease. However, it remains unknown whether there is a difference between patients on PD and hemodialysis (HD). In total, 73 PD and 34 HD patients who underwent brain magnetic resonance imaging (MRI) were recruited for a cross-sectional analysis. Among them, 42 PD and 25 HD patients who underwent a second brain MRI after 2 years were recruited for a longitudinal analysis. T1-weighted MRI images were analyzed. Total gray matter volume (GMV), total white matter volume, and cerebrospinal fluid volume were segmented, and each volume was quantified using statistical parametric mapping software. The ratio of GMV (GMR) was calculated by dividing GMV by intracranial volume, to adjust for variations in head size. We compared GMR between PD and HD patients in the cross-sectional analysis and the annual change in GMR (AC-GMR) in the longitudinal analysis. In the cross-sectional analysis, age- and sex-adjusted GMR was significantly lower in PD than HD patients [least square mean (LSM): 39.2% vs. 40.0%, P = 0.018]. AC-GMR was significantly greater in PD than HD patients and this difference remained significant even after adjustment for potential confounding factors (LSM: -0.68 vs. -0.28 percentage-points/year, P = 0.011). In conclusion, the present study demonstrated a more rapid progression of brain atrophy in PD patients compared with HD patients. We demonstrated that decline in GMR progressed significantly more rapidly in PD than HD patients independent of potential confounding factors. GMR gray matter volume ratio, HD hemodialysis, PD peritoneal dialysis.

Association between serum alkaline phosphatase and bacteraemia in haemodialysis outpatients: a multicentre retrospective cross-sectional study

OBJECTIVES

Elevated baseline serum alkaline phosphatase (ALP) may correlate with higher medium-term to long-term mortality in the general population and in patients with chronic kidney disease. However, few data are available on the association between serum ALP and the short-term prognosis of patients on haemodialysis (HD). We verified the association of ALP levels and bacteraemia or death in maintenance HD patients suspected of bacteraemia in an outpatient setting.

DESIGN

We analysed 315 consecutive HD patients suspected of having bacteraemia with two sets of blood culture drawn on admission.

SETTING

Admission to two tertiary-care university medical centres from January 2013 to December 2015.

PARTICIPANTS

Consecutive cases on maintenance HD aged≥18 years. Cases of hospitalised patients who had been transferred from another hospital, had a dialysis vintage<2 months, were also undergoing peritoneal dialysis, and/or were receiving HD less than once a week were excluded.

PRIMARY AND SECONDARY OUTCOME MEASURES

Primary outcome measure was bacteraemia and secondary outcome was in-hospital death.

RESULTS

Among 315 cases included in the study, 187 had baseline-measured ALP levels, with a cut-off value on ROC analysis of 360 U/L (Area Under the Curve (AUC) 0.60, sensitivity 0.49, specificity 0.76). In multivariate analysis, there was a statistically significant association between a higher ALP in hospital visit and bacteraemia (OR: 2.37, 95% CI: 1.17 to 4.83). However, there were no statistically significant associations between higher ALP and in-hospital death (OR: 1.20, 95% CI: 0.57 to 2.54). A sensitivity analysis of 187 patients with no missing ALP values also demonstrated a significant association between elevated ALP and bacteraemia, but no significant association between ALP and in-hospital death.

CONCLUSIONS

Elevated ALP is a predictor of bacteraemia. In HD patients suspected of bacteraemia in outpatient settings, increased ALP levels were associated with increased likelihood of confirmed disease.

A case of peritoneal dialysis-related peritonitis caused by dialysate leakage with successful treatment by intravenous and intraperitoneal antibiotic therapy

Dialysate leakage is one of the causes of peritoneal dialysis (PD)-related peritonitis. The rate of catheter removal in PD-related peritonitis caused by dialysate leakage (PDPDL) is high, and the correct treatment is unclear. We experienced a case of PDPDL that was treated with intravenous and intraperitoneal antibiotic therapy. A 44-year-old Japanese man had high glucose discharge from the exit site after 14 days of initiating PD, and he had a fever and cloudy effluent with a high white cell count. We diagnosed him with PDPDL and began to administer vancomycin and ceftazidime intraperitoneally. However, the peritonitis could not be ameliorated. A culture examination showed Staphylococcus aureus from the effluent of peritoneal cavity and exit site cultures. We began intraperitoneal cefazolin administration according to a drug susceptibility test, but the effluent cell count remained high. As we added intravenous cefazolin administration, his symptoms and cloudy effluent improved, and the effluent cell count normalized. He has not developed any recurrence of dialysate leakage or peritonitis. Our findings suggest that PD-related peritonitis accompanied by other infectious sites, such as PDPDL, should be treated with additional intravenous antibiotic therapy to taking effect on the infectious sites except for peritoneum and to keep plasma concentration of antibiotics sufficient especially in cases with preserved residual kidney function.

Stronger Effect of Azilsartan on Reduction of Proteinuria Compared to Candesartan in Patients with CKD: A Randomized Crossover Trial

INTRODUCTION

Angiotensin receptor blockers (ARBs) are preferably used in hypertensive patients with CKD. Azilsartan is a strong antihypertensive ARB, but its antiproteinuric effects are not well understood. We compared the antiproteinuric effect of azilsartan and candesartan in CKD patients in an open-label, randomized, crossover trial.

METHODS

A total of 111 patients were treated with 20 mg of azilsartan daily for 2 months as a run-in period. After the run-in period, patients were randomized into 2 arms and received either 20 mg of azilsartan or 8 mg of candesartan daily for 3 months in a crossover trial. The primary outcome was the percent change in urinary protein-to-Cr ratio (UPCR).

RESULTS

Ninety-five patients completed the trial. The mean age was 64.3 years. The estimated glomerular filtration rate (eGFR) and UPCR were 41.5 mL/min/1.73 m2 and 1.8 g/gCr, respectively. The baseline systolic and diastolic blood pressures were 131.4 and 71.0 mm Hg, respectively. The mean percent change in the UPCR was -3.8% in the azilsartan group and 30.8% in the candesartan group at the 1st endpoint (p = 0.0004), and 6.1% in the azilsartan group and 25.8% in the candesartan group at the 2nd (final) endpoint (p = 0.029). The incidence of adverse events, including eGFR levels and serum potassium levels, was not significantly different between the groups.

CONCLUSION

A 20 mg azilsartan dose had potent antiproteinuric effects compared with an 8 mg candesartan dose, without an increase in adverse events. Azilsartan may provide renal protection in addition to antihypertensive effects in CKD patients.

Added value of clinical prediction rules for bacteremia in hemodialysis patients: An external validation study

Introduction

Having developed a clinical prediction rule (CPR) for bacteremia among hemodialysis (HD) outpatients (BAC-HD score), we performed external validation.

Materials & methods

Data were collected on maintenance HD patients at two Japanese tertiary-care hospitals from January 2013 to December 2015. We enrolled 429 consecutive patients (aged ≥ 18 y) on maintenance HD who had had two sets of blood cultures drawn on admission to assess for bacteremia. We validated the predictive ability of the CPR using two validation cohorts. Index tests were the BAC-HD score and a CPR developed by Shapiro et al. The outcome was bacteremia, based on the results of the admission blood cultures. For added value, we also measured changes in the area under the receiver operating characteristic curve (AUC) using logistic regression and Net Reclassification Improvement (NRI), in which each CPR was added to the basic model.

Results

In Validation cohort 1 (360 subjects), compared to a Model 1 (Basic Model) AUC of 0.69 (95% confidence interval [95% CI]: 0.59–0.80), the AUC of Model 2 (Basic model + BAC-HD score) and Model 3 (Basic model + Shapiro’s score) increased to 0.8 (95% CI: 0.71–0.88) and 0.73 (95% CI: 0.63–0.83), respectively. In validation cohort 2 (96 subjects), compared to a Model 1 AUC of 0.81 (95% CI: 0.68–0.94), the AUCs of Model 2 and Model 3 increased to 0.83 (95% CI: 0.72–0.95) and 0.85 (95% CI: 0.76–0.94), respectively. NRIs on addition of the BAC-HD score and Shapiro’s score were 0.3 and 0.06 in Validation cohort 1, and 0.27 and 0.13, respectively, in Validation cohort 2.

Conclusion

Either the BAC-HD score or Shapiro’s score may improve the ability to diagnose bacteremia in HD patients. Reclassification was better with the BAC-HD score.

High low-density lipoprotein cholesterol as an independent risk factor for coronary restenosis in hemodialysis patients undergoing percutaneous coronary interventions

HD patients have been reported to have a higher risk of restenosis after percutaneous coronary intervention (PCI). The aim of this study was to investigate the risk factors of coronary restenosis in HD patients. We enrolled 54 HD patients (mean age: 66.5 ± 10.1 years; 72.2% men; mean HD duration: 3.7 years), who received PCI and follow-up coronary angiography. Of the patients, 22 (40.7%) had restenosis within 3 to 12 months of PCI. Univariate logistic analysis showed low-density lipoprotein cholesterol (LDL-C)/high-density lipoprotein cholesterol (HDL-C) ratio, LDL-C, non-HDL-C, and history of major adverse cardiovascular events were significantly associated with coronary restenosis (OR]: 1.89, 1.27, 1.22, and 5.79, respectively). Multivariate analysis showed that LDL-C was significantly associated with coronary restenosis (OR: 1.43). These data suggest that LDL-C is an independent risk factor for coronary restenosis in HD patients undergoing PCI, and strict lipid management may be required.

The Association between Dialysis Dose and Risk of Cancer Death in Patients Undergoing Hemodialysis: The Q-Cohort Study

Objective Uremic toxins are known risk factors for cancer in patients undergoing hemodialysis (HD). Although adequate removal of uremic toxins might reduce the cancer risk by improving subclinical uremia, the relationship between the dialysis dose and risk of cancer death in patients undergoing HD remains unclear. Methods In this prospective observational study, 3,450 patients undergoing HD were followed up for 4 years. The primary outcome was cancer death. Patients were divided into quartiles according to their baseline Kt/V levels. The association between the Kt/V levels and risk of cancer death was estimated using the Kaplan-Meier method and Cox proportional-hazards model. Results A total of 111 patients (3.2%) died from cancer during the 4-year observational period. The 4-year survival rate decreased linearly with decreasing Kt/V. The multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for cancer death were 2.23 (95% CI, 1.13-4.56), 1.77 (0.88-3.63), and 1.89 (1.04-3.56) in quartile (Q) 1, Q2, and Q3, respectively, compared with patients in the highest Kt/V category (Q4) (p for trend = 0.06). Every 0.1 increase in Kt/V was associated with a reduction of 8% in cancer death (HR 0.92, 95% CI, 0.85-0.99). Conclusion A lower dialysis dose might be associated with a higher risk of cancer death in patients undergoing HD. Kt/V is a simple indicator of dialysis dose used in clinical practice and might be a useful modifiable factor for predicting the risk of cancer death. Further basic and interventional studies are needed to confirm the apparent reduction in cancer death associated with increasing the dialysis dose.

Hemoglobin concentration and the risk of hemorrhagic and ischemic stroke in patients undergoing hemodialysis: the Q-cohort study

Background

The contribution of the hemoglobin concentration to the incidence of hemorrhagic or ischemic stroke in patients undergoing hemodialysis is unclear.

Methods

In total, 3436 patients undergoing prevalent hemodialysis were followed up for 4 years. The primary outcome was the first development of hemorrhagic or ischemic stroke. The baseline hemoglobin concentration was divided into quartiles [hemoglobin (g/dL): Q1, ≤9.7; Q2, 9.8-10.5; Q3, 10.6-11.1; Q4, ≥11.2]. The association between the hemoglobin concentration and each type of stroke was examined using the Kaplan-Meier method and a Cox proportional hazards model.

Results

During the follow-up period, 76 (2.2%) patients developed hemorrhagic stroke and 139 (4.0%) developed ischemic stroke. The 4-year incidence rate of hemorrhagic stroke was significantly higher in patients with lower hemoglobin concentrations. Compared with the quartile of patients with the highest hemoglobin concentrations (Q4), the multivariable-adjusted hazard ratios for hemorrhagic stroke were 1.18 (95% confidence interval, 0.56-2.51), 1.59 (0.82-3.21) and 2.31 (1.16-4.73) in patients in Q3, Q2 and Q1, respectively. No association was identified between the 4-year incidence rate of ischemic stroke and the hemoglobin concentration. Compared with the quartile of patients with the lowest hemoglobin concentrations (Q1), the multivariable-adjusted hazard ratios for ischemic stroke were 1.17 (95% confidence interval, 0.73-1.89), 0.88 (0.51-1.51) and 1.10 (0.66-1.83) in patients in Q2, Q3 and Q4, respectively.

Conclusions

Our results suggest that low hemoglobin concentrations are associated with a high risk of hemorrhagic stroke, but not of ischemic stroke, in patients undergoing hemodialysis.

The Incidence and Associated Factors of Sudden Death in Patients on Hemodialysis: 10-Year Outcome of the Q-Cohort Study

Aim: The incidence of sudden death and its risk factors in patients on hemodialysis remain unclear. This study aimed to clarify the incidence of sudden death and its risk factors in Japanese patients on hemodialysis.

Methods: A total of 3505 patients on hemodialysis aged ≥ 18 years were followed for 10 years. Multivariate-adjusted hazard ratio (HR) with 95% confidence interval (95% CI) of each risk factor of sudden death were calculated using a Cox proportional hazards model.

Results: During the 10-year follow-up, 1735 patients died, including 227 (13%) sudden deaths. The incidence rate of sudden death was 9.13 per 1000 person-years. In multivariable-adjusted Cox analysis, male sex (HR 1.67; 95% CI 1.20–2.33), age (HR 1.44; 95% CI 1.26–1.65 per 10-year higher), the presence of diabetes (HR 2.45; 95% CI 1.82–3.29), history of cardiovascular disease (HR 1.85; 95% CI 1.38–2.46), cardiothoracic ratio (HR 1.21; 95% CI 1.07–1.39 per 5% higher), serum C-reactive protein (HR 1.11; 95% CI 1.03–1.20 per 1-mg/dL higher), and serum phosphate (HR 1.15; 95% CI 1.03–1.30 per 1-mg/dL higher) were independent predictors of sudden death. A subgroup analysis stratified by sex or age showed that lower serum corrected calcium levels, not using vitamin D receptor activators in women, and a shorter dialysis session length in men or older people (≥ 65 years) increased the risk for sudden death.

Conclusions: This study clarified the incidence of sudden death and its specific predictors in Japanese patients on hemodialysis.

Rapidly Progressive Glomerulonephritis with Delayed Appearance of Anti-Glomerular Basement Membrane Antibody Successfully Treated with Multiple Courses of Steroid Pulse Therapy

Patients with anti-glomerular basement membrane (GBM) antibody glomerulonephritis typically exhibit rapidly progressive glomerulonephritis (RPGN). The renal outcome as well as the prognosis of this disease is worse than other forms of RPGN such as those from microscopic polyangiitis. Therefore, early therapeutic intervention is essential to improve its prognosis. One month before referral to our hospital, a 54-year-old female attended another hospital because of macrohematuria. At that time, she had proteinuria and macrohematuria with normal renal function, was negative for anti-GBM antibodies, and was diagnosed with chronic glomerulonephritis. A month later when she was admitted to our hospital, she showed renal insufficiency and was positive for anti-GBM antibodies. Immediately after recognizing the anti-GBM antibody status, plasma exchange and the first course of steroid pulse therapy was started. After 5 days of therapy, renal biopsy confirmed severe crescentic glomerulonephritis in which all the observed glomeruli were involved with cellular crescents. Despite this, she survived without end-stage renal disease after three courses of steroid pulse therapy and seven sessions of plasma exchange. This favorable outcome reflects the repeated analysis of anti-GBM antibodies within a very short period and the rapid therapeutic intervention in addition to the intensive immunosuppressive therapies.

Prognostic value of pre-dialysis blood pressure and risk threshold on clinical outcomes in hemodialysis patients: The Q-Cohort Study

The influence of pre-dialysis blood pressure (BP) on the prognosis of hemodialysis (HD) patients is still inconclusive.A total of 3436 HD patients were prospectively followed up for 4 years. The patients were divided into quintiles of pre-dialysis systolic BP (SBP) and diastolic BP (DBP) levels [mm Hg]: Quintile 1 (Q1), SBP <134, DBP <66; Q2, SBP 134 to 147, DBP 66 to 72; Q3, SBP 148 to 158, DBP 73 to 79; Q4, SBP 159 to 171, DBP 80 to 85; Q5, SBP ≥172, DBP ≥86. The association between the pre-dialysis BP and outcomes were examined using a Cox proportional hazards model.During a 4-year follow-up period, 564 (16.4%) patients died of any cause and 590 (17.2%) developed cardiovascular (CV) events. The lowest level of pre-dialysis SBP group (Q1) showed a significantly increased risk of all-cause mortality (hazard ratio [HR] 1.83, 95% confidence interval [CI] 1.40-2.39) and the highest group (Q5) significantly increased risk of CV events (HR 1.31, 95% CI 1.02-1.68) compared with the reference group (Q3), respectively. The highest level of pre-dialysis DBP group was significantly associated with increased risk for both all-cause mortality and CV events. Restricted cubic spline analysis for BP and outcomes suggested the optimal pre-dialysis BP value associated with the lowest risk of outcomes was SBP 152 mm Hg for all-cause mortality, SBP 143 mm Hg for CV events, and DBP 68 mm Hg for all-cause mortality.Our results suggested that pre-dialysis BP was independently associated with all-cause mortality and CV events among Japanese HD patients.

Clinic-level factors associated with collaboration with community pharmacies in Japan

The aim of this study was to clarify the clinic-level factors related to experiences of and attitudes toward collaboration with community pharmacies. We conducted a postal questionnaire survey of all clinics in Gifu, Japan, assessing the experiences and attitudes of representative clinical staff regarding the following activities in collaboration with community pharmacists: regional care meetings/service adjustment meetings, case study conferences, joint workshops/continuing education conferences, community services, information sharing through medical cooperation networks, and accompanying community pharmacists during home care. The factors significantly related to experiences of joint workshops/continuing education conferences included home care visits (odds ratio [OR] 2.39) and a 100 % out-of-hospital prescription ratio (OR 4.80). In contrast, only home care visits were significantly associated with consideration of information sharing through medical cooperation networks and accompanying community pharmacists during home care (OR 2.06 and 11.91, respectively). Finally, the factors significantly associated with considering implementing case study conferences and joint workshops/continuing education conferences included home care visits (OR 4.64 and 2.98, respectively) and a 100% out-of-hospital prescription ratio (OR 4.64 and 6.38). Overall, having more opportunities to communicate with community pharmacists and other healthcare professionals appeared to facilitate clinics' consideration of collaboration with community pharmacies, along with actual experiences.

Study on Dialysis Session Length and Mortality in Maintenance Hemodialysis Patients: The Q-Cohort Study

<b><i>Objectives:</i></b> Hemodialysis (HD) time has been recognized as an important factor in dialysis adequacy. However, few studies have reported on associations between HD time and prognosis among maintenance HD patients. We present some findings from a prospective cohort study, the ­Q-Cohort Study, which was set up to explore risk factors for mortality in Japanese HD patients. We hypothesized that HD ≥5 h was associated with a significant survival advantage compared with HD &#x3c; 5 h. The present study examined association between HD time and mortality in Japanese HD patients. <b><i>Methods:</i></b> The prospective multicenter Q-Cohort Study was conducted between December 2006 and December 2010, following 3,456 Japanese HD patients for 4 years. We examined the association between HD time and prognosis using Cox proportional hazards modeling. Propensity scores were calculated using logistic regression. <b><i>Results:</i></b> During follow-up, 566 patients died from any cause. Patients with HD ≥5 h (<i>n</i> = 2,141) showed ­significantly lower risk of all-cause death (hazards ratio = 0.82; 95% CI 0.68–0.99) than those with HD &#x3c; 5 h (<i>n</i> = 1,315), after adjusting for confounding risk factors. This ­association remained significant using a propensity score-based approach. After stratifying the analysis by patient age in 10-year increments, this finding remained ­significant only in patients who were ≥80 years of age. <b><i>Conclusion:</i></b> Our results suggest that HD ≥5 h has a more favorable effect on mortality than HD &#x3c; 5 h.

Repeated Paradoxical Brain Infarctions in a Patient on Self-Managed Home Hemodialysis Using a Long-Term Indwelling Catheter

We describe the case of a 51-year-old Japanese man with an end-stage kidney disease caused by a 30-year history of type 1 diabetes mellitus. The patient had suffered repeated bilateral multiple brain infarctions within a short period of time after the initiation of a self-managed daily home hemodialysis regimen using a long-term indwelling catheter inserted into the right atrium. Despite extensive examinations, we could not find any embolic causes except for the catheter and a patent foramen ovale (PFO). The patient had experienced repeated brain infarctions under antiplatelet and anticoagulation therapies, but suffered no further brain infarctions after the removal of the catheter and the alteration of vascular access from the catheter to an arteriovenous fistula in the forearm. We speculate that the indwelling catheter-associated thrombi or air and the right-to-left shunt through the PFO may have caused the repeated paradoxical brain embolisms in this patient.

Cardiothoracic Ratio and All-Cause Mortality and Cardiovascular Disease Events in Hemodialysis Patients: The Q-Cohort Study

BACKGROUND

Cardiothoracic ratio by chest radiography is commonly used to assess volume status. Little is known about the relationships between cardiothoracic ratio and the incidence of clinical outcomes in patients undergoing hemodialysis (HD).

STUDY DESIGN

Prospective cohort study.

SETTING & PARTICIPANTS

3,436 participants in the Q-Cohort Study 18 years or older who underwent maintenance HD in Japan.

PREDICTOR

Cardiothoracic ratio.

OUTCOMES & MEASUREMENTS

All-cause mortality and cardiovascular disease (CVD) events.

RESULTS

During a 4-year follow-up period, 564 (16.4%) patients died of any cause and 590 (17.2%) developed CVD events. From baseline cardiothoracic ratios, participants were categorized into sex-specific quartiles because cardiothoracic ratio distribution differed by sex. The 4-year event-free survival rate, in terms of all-cause mortality and CVD events, was significantly lower with higher cardiothoracic ratios. Compared to the lowest cardiothoracic ratio (quartile 1), multivariable-adjusted HRs for all-cause mortality were 0.89 (95% CI, 0.66-1.20), 1.41 (1.08-1.86), and 1.52 (1.17-2.00) in patients from quartiles 2, 3, and 4, respectively. Similarly, in comparison to quartile 1, multivariable-adjusted HRs for CVD events were 1.00 (95% CI, 0.77-1.31), 1.18 (0.92-1.53), and 1.37 (1.07-1.76) in patients from quartiles 2, 3, and 4, respectively. Furthermore, the combination of higher cardiothoracic ratio and normohypotension (systolic blood pressure < 140mmHg and diastolic blood pressure < 90mmHg) was associated with higher risk for CVD events.

LIMITATIONS

Single measurement of all variables, potentially less-heterogeneous patient population, and limited ascertainment of cardiac parameters and the outcomes.

CONCLUSIONS

Higher cardiothoracic ratio is associated with higher risk for both all-cause mortality and CVD events in patients undergoing HD.

Association Between Serum Phosphate Levels and Stroke Risk in Patients Undergoing Hemodialysis: The Q-Cohort Study

BACKGROUND AND PURPOSE

The contribution of serum phosphate levels to stroke risk in dialysis patients remains unclear. The present study aimed to elucidate the respective association between serum phosphate levels and the risk of brain hemorrhage or infarction in patients undergoing hemodialysis.

METHODS

A total of 3437 patients undergoing hemodialysis were followed up for a median of 3.9 years. The primary outcome was the occurrence of brain hemorrhage or infarction. Patients were divided into 4 groups based on their baseline serum phosphate levels (Q1-Q4). Stroke risk was estimated using a Cox proportional hazards model.

RESULTS

During the follow-up period, 75 patients experienced brain hemorrhage and 139 experienced brain infarction. The risk of brain hemorrhage was significantly higher in the highest (Q4) compared with the lowest quartile (Q1) as the reference value (multivariate-adjusted hazard ratio [95% confidence intervals]: Q1, 1.00; Q2, 1.76 [0.79-4.18]; Q3, 1.99 [0.92-4.67]; and Q4, 2.74 [1.27-6.47]; P=0.077 for trend; hazard ratio for every 1 mmol/L increase in serum phosphate level, 2.07 [1.10-3.81]; P=0.025). In contrast, the risk of brain infarction was significantly higher in Q1 (P=0.045) compared with Q3 as the reference value (Q1, 1.65 [1.01-2.73]; Q2, 1.35 [0.82-2.25]; Q3, 1.00; and Q4, 1.30 [0.77-2.20]).

CONCLUSIONS

Higher serum phosphate levels were associated with an increased risk of brain hemorrhage, whereas low levels were associated with an increased risk of brain infarction in hemodialysis patients. These results suggest the importance of managing serum phosphate levels within an appropriate range in hemodialysis patients.

CLINICAL TRIAL REGISTRATION

URL: http://www.umin.ac.jp/. Unique identifier: UMIN000000556.

The Fukuoka Kidney disease Registry (FKR) Study: design and methods

BACKGROUND

Chronic kidney disease (CKD) is an established independent risk factor for progression to end-stage renal disease (ESRD) and incidence of cardiovascular disease (CVD). The onset and progression of CKD are associated with both genetic predisposition and various lifestyle-related factors, but little is known about the influence of genetic-environmental interactions on the incidence of ESRD or CVD in patients with CKD.

METHODS

The Fukuoka Kidney disease Registry (FKR) Study is designed as one of the largest prospective, multicenter, observational cohort studies in non-dialysis dependent CKD patients. The FKR Study aims to enroll approximately 5000 individuals at multiple clinical centers and follow them for up to at least 5 years. At baseline, subjects enrolled in the FKR Study will fill out extensive lifestyle-related questionnaires. Further, their health status and treatments will be monitored annually through a research network of nephrology centers. Blood and urine samples, including DNA/RNA, will be collected at the time of enrolment and every 5-years follow-up.

CONCLUSIONS

The FKR Study will provide many insights into the onset and progression of CKD, which will suggest hypothesis-driven interventional clinical trials aimed at reducing the burden of CKD. The features of the FKR Study may also facilitate innovative research to identify and validate novel risk factors, including genetic susceptibility and biomarkers, using biomaterials by high-throughput omics technologies.

Functional analysis of recombinant 2-Cys peroxiredoxin from the hard tick Haemaphysalis longicornis

Ticks are obligate haematophagous arthropods that feed on vertebrate blood containing high levels of iron. The host-derived iron reacts to oxygen in the tick's body, and then high levels of reactive oxygen species, including hydrogen peroxide (H(2)O(2)), may be generated. High levels of H(2)O(2) cause oxidative stress to aerobic organisms. Therefore, antioxidant responses are necessary to control H(2)O(2). We focused on peroxiredoxins (Prxs), H(2)O(2) -scavenging enzymes. The sequence of Haemaphysalis longicornis 2-Cys Prx (HlPrx2) was identified from fat body cDNA libraries of this tick and recombinant HlPrx2 was then prepared using Escherichia coli. By comparison with the 2-Cys Prxs of other organisms, we found two conserved cysteines in HlPrx2, Cys51 and Cys172. We examined the antioxidant activity of HlPrx2 and mutant proteins produced by a single base substitution, converting one or both of these cysteines into serines. The assays revealed that proteins containing Cys51 showed antioxidant activity when H(2)O(2) was removed. Sodium dodecyl sulphate polyacrylamide gel electrophoresis and size-exclusion chromatography demonstrated that only the wild-type HlPrx2 formed homodimers and that all of the proteins that we made had a high molecular weight peak. These results indicate that both Cys51 and Cys172 are essential for the dimerization of HlPrx2, whereas only the Cys51 residue is necessary for antioxidant activity.

Erythropoiesis-stimulating agent slows the progression of chronic kidney disease: a possibility of a direct action of erythropoietin

BACKGROUND

Controversy exists regarding the renoprotective effect of erythropoiesis-stimulating agent (ESA) in progressive chronic kidney disease (CKD) with renal anemia. In this study, we examined whether ESA therapy has a renoprotective effect in progressive CKD.

METHODS

The subjects in this retrospective observational study were 68 non-dialysis dependent CKD patients with renal anemia. We compared the progression rate (PR), defined by the slope of the linear regression line of estimated glomerular filtration rate, measured during 6 months just before and after the start of ESA therapy. We also investigated the factors affecting renoprotective efficacy of ESA therapy against the progression of CKD.

RESULTS

Median (interquartile range) PR decreased significantly from 6.2 (3.7-12.7) to 4.0 (-0.3 to 7.3) mL/min/1.73 m(2)/year after the start of ESA therapy. Blood pressure levels and rate of medication with renin-angiotensin system inhibitors were comparable between the two periods. Next, we investigated the factors affecting renoprotective efficacy of ESA therapy against the progression of CKD. Thirty patients were good renal responders, defined as those with the ratio of post-/pre-PR of <0.5 and the difference of pre- minus post-PR >5.0 mL/min/1.73 m(2)/year, and 38 patients were poor renal responders who did not meet the definition of good renal responders. Multivariable logistic regression analysis showed that weekly ESA dose, but not increase in hemoglobin level, was a significant and independent determinant of the renoprotective effect of ESA.

CONCLUSION

ESA therapy slows the progression of CKD and part of the effect might be attributed to the direct renoprotective action of ESA.

Clinical Significance of Fronto-Temporal Gray Matter Atrophy in Executive Dysfunction in Patients with Chronic Kidney Disease: The VCOHP Study

Background & Objectives

It is well known that cognitive impairment in patients with chronic kidney disease (CKD) is characterized by executive dysfunction, rather than memory dysfunction, although the precise mechanism of this remains to be elucidated. The purpose of the present study is to examine the correlation between gray matter volume (GMV) and executive function in CKD patients.

Design, Setting, Participants, Measurements

This cross-sectional study recruited 95 patients with non-dialysis-dependent CKD (NDD-CKD) with no history of cerebrovascular disease, who underwent brain magnetic resonance imaging (MRI) and Trail Making Test (TMT) in the VCOHP Study. The subjects underwent brain MRI and TMT part A (TMT-A) and part B (TMT-B). The segmentation algorithm from Statistical Parametric Mapping 8 software was applied to every T1-weighted MRI scan to extract tissue maps corresponding to gray matter, white matter, and cerebrospinal fluid. GMV was normalized by dividing by the total intracranial volume, calculated by adding GMV, white matter volume, and cerebrospinal fluid space volume. Then, normalized whole-brain GMV was divided into four categories of brain lobes; frontal, parietal, temporal, and occipital. We assessed the correlation between normalized GMV and TMT using multivariable regression analysis.

Results

Normalized whole-brain GMV was significantly inversely correlated to the scores of TMT-A, TMT-B, and ΔTMT (TMT-B minus TMT-A). These correlations remained significant even after adjusting for relevant confounding factors. Normalized frontal and temporal GMV, but not parietal and occipital GMV, were significantly inversely correlated with TMT-A, TMT-B, and ΔTMT using multivariable regression analysis.

Conclusions

The present study demonstrates the correlation between normalized GMV, especially in the frontal and temporal lobes, and executive function, suggesting that fronto-temporal gray matter atrophy might contribute to executive dysfunction in NDD-CKD.

Membranoproliferative glomerulonephritis with predominant IgG2 and IgG3 deposition in a patient with IgG4-related disease

Background

IgG4-related disease is a novel disease entity characterized by elevated serum IgG4 and tissue infiltration by IgG4-positive plasma cells. Typical renal pathology is tubulointerstitial nephritis with storiform fibrosis, although the co-existence of various glomerular lesions has been described. Here, we present the first report of a case of IgG4-related kidney disease and membranoproliferative glomerulonephritis showing the discrepancy in IgG subclasses between the kidney interstitium and glomeruli.

Case presentation

A 70-year-old Japanese woman was diagnosed with membranoproliferative glomerulonephritis and focal tubulointerstitial nephritis with IgG4-positive plasma cells. Immunofluorescence studies revealed predominant deposition of IgG3 and IgG2, but not IgG4 in the glomeruli. We administered oral prednisolone at 30 mg/day, and the abnormalities in urine and blood tests gradually resolved.

Conclusion

In this case, different patterns of IgG subclasses detected in the glomeruli and interstitial plasma cells suggest overlapping immunologic abnormalities. The favorable clinical course in our patient suggests that steroid therapy is promising in cases of IgG4-related kidney disease accompanied by glomerulonephritis.

Improvement in spatial memory dysfunction by telmisartan through reduction of brain angiotensin II and oxidative stress in experimental uremic mice

AIMS

We previously reported that chronic uremia induces spatial working memory dysfunction in mice, and that it is attributed to cerebral oxidative stress. The source of oxidative stress was considered to be uremic toxins, but this remains unclear. In the present study, we examined whether the brain renin-angiotensin system was activated in the CKD mouse model, and whether it contributed to cognitive impairment.

MAIN METHODS

CKD was induced in 8-week-old male mice by 5/6 nephrectomy. Mice were divided into four groups: control mice administered tap water (Cont-V), control mice treated with 0.5mg/kg/day telmisartan, an angiotensin II (AII) receptor blocker, for 8 weeks (Cont-T), CKD mice administered tap water (CKD-V), and CKD mice treated with 0.5 mg/kg/day telmisartan for 8 weeks (CKD-T). After the treatment period, a radial arm water maze (RAWM) test was performed, and angiotensin II (AII) concentrations and markers of oxidative stress were measured in the brains of mice.

KEY FINDINGS

Errors in the RAWM test were more frequent in the CKD-V group than in the Cont-V group. In addition, errors in the CKD-T group were comparable to control mice. Tissue brain AII concentrations were greater in the CKD-V group compared with the other groups. Oxidative DNA damage and lipid peroxidation in the brain were also greater in the CKD-V group compared with the other groups.

SIGNIFICANCE

Our results suggest that brain AII levels were exaggerated in CKD mice, and that this contributes to cognitive impairment through oxidative stress.

Impact of combined losartan/hydrochlorothiazide on proteinuria in patients with chronic kidney disease and hypertension

It is unknown whether the use of diuretics is optimal over other antihypertensive agents in patients with chronic kidney disease (CKD) whose blood pressure remains uncontrolled despite treatment with renin-angiotensin system (RAS) inhibitors. In this study, we assessed the additive effects of hydrochlorothiazide (HCTZ) on reducing proteinuria in CKD patients under treatment with losartan (LS). We conducted a multicenter, open-labeled, randomized trial. One hundred and two CKD patients with hypertension and overt proteinuria were recruited from nine centers and randomly assigned to receive either LS (50 mg, n=51) or a combination of LS (50 mg per day) and HCTZ (12.5 mg per day) (LS/HCTZ, n=51). The primary outcome was a decrease in the urinary protein-to-creatinine ratio (UPCR). The target blood pressure was <130/80 mm Hg, and antihypertensive agents (other than RAS inhibitors and diuretics) were added if the target was not attained. Baseline characteristics of the two groups were similar. After 12 months of treatment, decreases in the UPCR were significantly greater in the LS/HCTZ group than in the LS group. There were no significant differences in blood pressure or the estimated glomerular filtration rate between the two groups. LS/HCTZ led to a greater reduction in proteinuria than treatment with LS, even though blood pressure in the LS group was similar to that in the LS/HCTZ group following the administration of additive antihypertensive agents throughout the observation period. This finding suggests that LS/HCTZ exerts renoprotective effects through a mechanism independent of blood pressure reduction.

The antioxidant tempol ameliorates arterial medial calcification in uremic rats: important role of oxidative stress in the pathogenesis of vascular calcification in chronic kidney disease

Vascular calcification is closely related to cardiovascular morbidity and mortality. Accumulating data indicate that oxidative stress is associated with dysfunction of various organs, including cardiovascular diseases in chronic kidney disease (CKD). However, it remains undetermined if oxidative stress induced by uremia promotes arterial medial calcification. The present study investigated the role of oxidative stress in the pathogenesis of arterial medial calcification in uremic rats. Rats with uremia induced by adenine-rich diet progressively developed arterial medial calcification, which was accompanied by time-dependent increases in both aortic and systemic oxidative stress. Immunohistochemical and biochemical analyses showed that the arterial medial calcification progressed in a time-dependent manner that is parallel to the osteogenic transdifferentiation of vascular smooth muscle cells. Accumulation of oxidative stress was also identified in the calcified regions. Time-course studies indicated that both oxidative stress and hyperphosphatemia correlated with arterial medial calcification. Tempol, an antioxidant, ameliorated osteogenic transdifferentiation of vascular smooth muscle cells and arterial medial calcification in uremic rats, together with reduction in aortic and systemic oxidative stress levels, without affecting serum biochemical parameters. Our data suggest that oxidative stress induced by uremia can play a role in the pathogenesis of vascular calcification in CKD, and that antioxidants such as tempol are potentially useful in preventing the progression of vascular calcification in CKD.

Observation of three-dimensional internal structure of steel materials by means of serial sectioning with ultrasonic elliptical vibration cutting

A three-dimensional (3D) internal structure observation system based on serial sectioning was developed from an ultrasonic elliptical vibration cutting device and an optical microscope combined with a high-precision positioning device. For bearing steel samples, the cutting device created mirrored surfaces suitable for optical metallography, even for long-cutting distances during serial sectioning of these ferrous materials. Serial sectioning progressed automatically by means of numerical control. The system was used to observe inclusions in steel materials on a scale of several tens of micrometers. Three specimens containing inclusions were prepared from bearing steels. These inclusions could be detected as two-dimensional (2D) sectional images with resolution better than 1 mum. A three-dimensional (3D) model of each inclusion was reconstructed from the 2D serial images. The microscopic 3D models had sharp edges and complicated surfaces.

Enrichment of marine anammox bacteria from seawater-related samples and bacterial community study

Anaerobic ammonium oxidation (anammox) is a novel nitrogen pathway catalyzed by anammox bacteria which are obligate anaerobic chemoautotrophs. In this study, enrichment culture of marine anammox bacteria (MAAOB) from the samples related to seawater was conducted. Simultaneous removal of ammonium and nitrite was confirmed in continuous culture inoculated with sediment of a sea-based waste disposal site within 50 days. However, no simultaneous nitrogen removal was observed in cultures inoculated with seawater-acclimated denitrifying sludge or with muddy sediment of tideland even during 200 days. Nitrogen removal rate of 0.13 kg/m(3)/day was achieved at nitrogen loading rate of 0.16 kg/m(3)/day after 320th days in the culture inoculated with the sediment of waste disposal site. The nitrogen removal ratio between ammonium nitrogen and nitrite nitrogen was 1:1.07. Denaturing gradient gel electrophoresis (DGGE) analysis indicated that an abundance of the bacteria close to MAAOB and coexistence of ammonium oxidizing bacteria and denitrifying bacteria in the culture.

Enhancement of settling tank capacity using a new type of tube settler

The effectiveness of a newly developed lamellar settler was confirmed by onsite experiments. The device had inclined parallel plates arranged in a vertical direction in a settling tank. This vertical arrangement method enables many more plates to be set compared to the conventional horizontal arrangement. As an original and distinctive innovation, both the right and left edges of the plates were closed, for removing the clear water between the plates, The tube settler modules were installed in a final settling tank of a sewage treatment plant. Tests conducted over a 9 months period showed that the system operated successfully and under normal operation conditions, the new device could treat almost the same flow rate as that treated by a conventional tank, 5,000 m(3)/day. For storm water, the new tube settler was demonstrated to enhance the settling tank capacity by up to 3 times.

Nitric oxide attenuates vascular endothelial cadherin-mediated vascular integrity in human chronic inflammation

In this study, we examined the role of nitric oxide (NO) in controlling vascular integrity mediated by vascular endothelial (VE)-cadherin in chronic inflammation. Periapical granulomas were analysed for the expression of inducible NO synthase (iNOS) and VE-cadherin, and more iNOS expression than VE-cadherin was shown. Human umbilical vein endothelial cells (HUVECs) were stimulated with proinflammatory cytokines and lipopolysaccharide extracted from Porphyromonas gingivalis and it induced iNOS expression, whereas it reduced VE-cadherin expression, compared with negative controls. On the other hand, pre-incubation with 1400W, an iNOS-specific inhibitor, markedly reduced iNOS expression in stimulated HUVECs and restored VE-cadherin expression to its control level, suggesting that vascular integrity was modulated in conjunction with the reduction of NO. Immunocytochemistry confirmed the functional role of NO in cultured HUVEC monolayers with or without 1400W. These data are consistent with a hypothesis suggesting that NO could attenuate VE-cadherin-mediated vascular integrity in human chronic inflammation.

C3 contributes to the cross-protective immunity induced by Babesia gibsoni phosphoriboprotein P0 against a lethal B. rodhaini infection

We have studied the impact of complement component 3 (C3) deficiency on the progression of lethal Babesia rodhaini infection in immune mice. A B. gibsoni ribosomal phosphoprotein P0 (BgP0) previously reported to be a cross-protective antigen against Babesia infection was used to immunize C57BL/6 wild-type (WT) and C3-deficient (C3-/-) mice. Test mice were immunized intraperitoneally (i.p.) with recombinant BgP0 (rBgP0), while controls either were immunized with PBS or did not receive any immunization. Following the immunization regime, test WT mice induced a specifically strong humoral response consisting of mixed immunoglobulins IgG1 and IgG2 associated with high production of IFN-gamma in the supernatant of splenocytes. While test C3-/- mice had significantly decreased total IgG, IgG1 and IgG2b responses, the secretions of IL-12 and IFN-gamma tended to be lower than those in WT mice. Furthermore, partial protection was only observed in rBgP0-immunized WT mice but not in C3-/- mice or controls. Indeed, rBgP0-immunized WT mice showed significant reductions in the initiation of parasitaemia correlated with delayed mortalities and considerable survival rates. Taken together, our results indicate that cross-protection was impaired in C3-/- mice in view of the decrease in the antibody responses and cytokine production and the high susceptibility to infection.

Tubulointerstitial nephritis and IgA nephropathy in a patient with advanced lung cancer treated with long-term gefitinib

A 52-year-old Japanese female was admitted to our hospital for microhematuria, proteinuria and progressive renal dysfunction. Two years prior to admission, she was diagnosed with lung adenocarcinoma and multiple bone and brain metastases, and was treated with gefitinib (250 mg/day). Treatment for 6 months induced partial response with 30% regression of the primary lung tumor, and resolution of metastatic tumors. After confirmation of the partial remission state, we performed percutaneous renal biopsy. Glomeruli showed mild to moderate mesangial proliferation, segmental endocapillary proliferation and occasional fibrocellular crescent formation. In addition, severe interstitial fibrosis and tubular atrophy relative to the degree of glomerular sclerosis were noted. Immunofluorescence microscopy showed predominant IgA deposition in the mesangial area. Electron microscopy revealed subepithelial and paramesangial electron-dense deposits. In consideration of the prognosis of lung cancer and complication of immunosuppressive treatment, we continued gefitinib only and closely followed-up the clinical course in the outpatient clinic. Sixteen months later, she continued to have proteinuria and microhematuria, and the severity of renal dysfunction was still the same. However, the lung cancer started to increase in size. This is quite an unusual case presenting histologically with tubulointerstitial nephritis and IgA nephropathy in a patient on long-term treatment with gefitinib.

Molecular characterization of a novel 32-kDa merozoite antigen of Babesia gibsoni with a better diagnostic performance by enzyme-linked immunosorbent assay

We cloned and expressed a novel gene encoding a 32-kDa merozoite protein of Babesia gibsoni (BgP32). The length of nucleotide sequence of the cDNA was 1464 bp with an open reading frame of 969 bp. The truncated recombinant BgP32 (rBgP32) without a signal peptide and C-terminal hydrophobic sequence was expressed in Escherichia coli as a soluble glutathione-S-transferase (GST) fusion protein. Western blotting demonstrated that the native protein was 32-kDa, consistent with molecular weight of the predicted mature polypeptide. Enzyme-linked immunosorbent assay (ELISA) using rBgP32 detected specific antibodies from 8 days to 541 days post-infection in the sequential sera from a dog experimentally infected with B. gibsoni. Moreover, the antigen did not cross-react with B. canis subspecies and closely related protozoan parasites, indicating that rBgP32 is a specific diagnostic antigen. Analysis of 47 sera taken from dogs with anaemic signs revealed that rBgP32 detected a higher proportion of B. gibsoni seropositive samples (77%) than its previously identified rBgP50 (68%) homologue. These results indicate that the BgP32 is a novel immunodominant antigen of B. gibsoni, and rBgP32 might be useful for diagnosis of B. gibsoni infection.

A trypanosome species isolated from naturally infected Haemaphysalis hystricis ticks in Kagoshima Prefecture, Japan

Common arthropod vectors for trypanosomes are flies, fleas and bugs. This study reports on an unknown trypanosome species isolated from naturally infected Haemaphysalis hystricis ticks, hereby, referred to as Trypanosoma KG1 isolate. The parasite has been successfully cultured in vitro with L929 or HEK 293T cell line as feeder cells. This trypanosome cannot survive in vitro without feeder cells. Following experimental infections of ticks, the trypomastigote-like and the epimastigote-like forms of this trypanosome could be detected by Giemsa-stained smears of the midgut and salivary glands of Ornithodoros moubata ticks which were made to feed on a culturing medium containing Trypanosoma KG1 isolate through an artificial membrane. Trypanosoma KG1 isolate could also be detected from Giemsa-stained smears of the haemolymph up to 30 days post-inoculation into the O. moubata haemocoel. Trypanosoma KG1 isolate cannot be propagated in laboratory animals including mice, rats, rabbits and sheep. A phylogenetic tree constructed with the 18S rRNA gene indicates that Trypanosoma KG1 is a member of the stercorarian trypanosomes.

Midodrine Hydrochloride and l-threo-3,4-dihydroxy-Phenylserine Preserve Cerebral Blood Flow in Hemodialysis Patients With Orthostatic Hypotension

Orthostatic hypotension (OH) after hemodialysis (HD) is a serious complication, as it causes various neurological symptoms and even ischemic brain damage. The aim of the present study was to evaluate the effects of antihypotensive agents, midodrine hydrochloride (MID) and L-threo-3,4-dihydroxyphenylserine (L-DOPS), on OH after HD. We measured systolic blood pressure (SBP) and cerebral blood flow velocity in the middle cerebral artery (MCVm, by transcranial Doppler sonography), in patients with OH during a 5-min 60-degree head-up tilt test at both before and after 4-week treatment with MID at 4 mg/day (N = 6) or L-DOPS at 400 mg/day (N = 7). Both MID and L-DOPS did not significantly protect against falls in systolic BP (SBP) after passive head-up tilt. However, a significant improvement was achieved in MCVm-decrement in the MID group at 3 min and the L-DOPS group at 0, 1 and 3 min during head-up tilt. Although MID and L-DOPS did not prevent OH after HD in HD patients, both agents preserved cerebral blood flow during orthostasis in HD patients with OH.

Acute renal infarction in a patient with left atrial myxoma

A 24-year-old male first attended our hospital with acute onset of right flank pain radiating to the right lower quadrant of the abdomen. A contrast-enhanced computer tomography (CT) scan showed renal infarction, and he was admitted immediately for treatment. On admission, the right lower abdominal pain diminished gradually. On the second day in hospital, a left atrial echogenic mass was detected which filled the left atrial cavity; it appeared to be a left atrial myxoma measuring 3.9+/-4.9 cm. The patient was immediately transferred and underwent emergency surgery. Histologic examination confirmed the diagnosis of myxoma. Post-operatively, he recovered well and was discharged from hospital without any further specific treatment.

Babesiaparasites develop and are transmitted by the non-vector soft tickOrnithodoros moubata(Acari: Argasidae)

Ornithodoros moubataticks were fed on blood infected withBabesia equi. However, the parasites were quickly cleared as evidenced by the disappearance ofB. equi-specific ribosomal RNA from the ticks. We hypothesized that if theBabesiaparasite can escape midgut-associated barriers a non-vector tick can become infected withBabesia. To test this hypothesis,B. equiparasite-infected blood fromin vitroculture was injected into the haemocoel of ticks.B. equi-specific rRNA was surprisingly detected 45 days after injection even in the eggs.Babesia-free dogs were infested withO. moubataticks that were infected by inoculation withB. gibsoni-infected red blood cells. Parasitaemia and antibody production against Bg-TRAP ofB. gibsoniincreased gradually. These results indicate thatO. moubatamay be a useful vector model forBabesiaparasites and also a very important tool for studies on tick immunity againstBabesiaparasites and tick-Babesiainteractions.