Epigenetic clocks indicate that kidney transplantation and not dialysis mitigate the effects of renal ageing

BACKGROUND

Chronic kidney disease (CKD) is an age-related disease that displays multiple features of accelerated ageing. It is currently unclear whether the two treatment options for end-stage kidney disease (dialysis and kidney transplantation [KT]) ameliorate the accelerated uremic ageing process.

METHODS

Data on clinical variables and blood DNA methylation (DNAm) from CKD stage G3-G5 patients were used to estimate biological age based on blood biomarkers (phenotypic age [PA], n = 333), skin autofluorescence (SAF age, n = 199) and DNAm (Horvath, Hannum and PhenoAge clocks, n = 47). In the DNAm cohort, we also measured the change in biological age 1 year after the KT or initiation of dialysis. Healthy subjects recruited from the general population were included as controls.

RESULTS

All three DNAm clocks indicated an increased biological age in CKD G5. However, PA and SAF age tended to produce implausibly large estimates of biological age in CKD G5. By contrast, DNAm age was 4.9 years (p = 0.005) higher in the transplantation group and 5.9 years (p = 0.001) higher in the dialysis group compared to controls. This age acceleration was significantly reduced 1 year after KT, but not after 1 year of dialysis.

CONCLUSIONS

Kidney failure patients displayed an increased biological age as estimated by DNAm clocks compared to population-based controls. Our results suggest that KT, but not dialysis, partially reduces the age acceleration.

Fibrates and the risk of cardiovascular outcomes in chronic kidney disease patients

BACKGROUND AND HYPOTHESIS

The high risk of major adverse cardiovascular events (MACE) in patients with chronic kidney disease (CKD) has been well described. However, the efficacy of fibrates on the risk of MACE in patients with CKD remains unclear.

METHODS

We conducted a nested case-control study using data from a large administrative database that included more than 1.5 million Japanese patients. We defined cases as CKD patients with incidences of MACE and matched them with controls based on age, sex, calendar year of cohort entry, and CKD stage. Fibrate exposure timing was categorized as current, recent, or past. A conditional logistic regression analysis was used to investigate the association between fibrate use and the risk of MACE.

RESULTS

Our study included 47 490 patients with CKD, with 15 830 MACE identified during a median follow-up of 9.4 months. The number of fibrates used during the study period were 556 (3.5%) in the case group and 1 109 (3.5%) in the control group. Fibrate use was significantly associated with a decreased risk of MACE (odds ratio [OR], 0.84; 95% confidence interval [CI], 0.75 to 0.94), particularly for current (OR, 0.81; 95% CI, 0.68-0.97) and recent use (OR, 0.65; 95% CI, 0.48-0.90). Regarding the class effect of fibrates, pemafibrate use, but not bezafibrate or fenofibrate use, was significantly associated with a decreased risk of MACE (OR, 0.73; 95% CI, 0.528-0.997).

CONCLUSION

Recent and current fibrate use, especially pemafibrate use, was associated with a reduced risk of MACE in patients with CKD. This suggests the potential benefits of continuous fibrate therapy and the possible superiority of pemafibrate over other fibrates. However, further investigations in different populations are required to confirm the generalizability of these findings.

α-Blocker Use in Hemodialysis: The Japan Dialysis Outcomes and Practice Patterns Study

Rationale & Objective

Despite α-blockers' use for hypertension as add-on therapy in patients treated with hemodialysis, scant information is available on their association, particularly with safety, in these patients.

Study Design

Prospective cohort study.

Setting & Participants

patients treated with hemodialysis and receiving antihypertensive agents in the Japan Dialysis Outcomes and Practice Patterns Study, phases 4-6, were analyzed.

Exposure

Primary exposure was the prescription of α-blocking antihypertensive agents at baseline.

Outcomes

Incident fractures, falls, and all-cause mortality.

Analytical Approach

Multivariable Cox and modified Poisson regression analysis.

Results

Of 5,149 patients treated with hemodialysis (mean age, 65 years; 68% men) receiving antihypertensive drugs, 717 (14%) received α-blocking agents. During a mean follow-up period of 2.0 years, 247 fractures, 525 falls, and 498 deaths occurred. Multivariable analysis showed no significant association of α-blocker use and increased risk of fractures (hazard ratio [HR], 0.92 [95% confidence interval {CI}, 0.61-1.38]), falls (HR, 0.94 [95% CI, 0.74-1.20]), or all-cause deaths (HR, 0.87 [95% CI, 0.64-1.20]) compared with α-blocker nonuse. α-Blocker use was, however, significantly associated with a decreased risk of all-cause mortality in the subgroup analysis, for example, patients who were older (HR, 0.71 [95% CI, 0.51-0.99]), were women (HR, 0.68 [95% CI, 0.48-0.95]), or reported a history of cardiovascular disease (HR, 0.67 [95% CI, 0.48-0.95]) or a predialysis blood pressure of ≥140 mm Hg (HR, 0.69 [95% CI, 0.49-0.98]).

Limitations

Selection bias cannot be ruled out given the prevalent user analysis.

Conclusions

No significant association between α-blocker use and the risk of worse safety-related outcomes was seen, indicating that clinicians may safely prescribe α-blockers to patients receiving hemodialysis who require blood pressure lowering.

Plain-Language Summary

α-Blockers have been generally reserved for use as add-on therapy for resistant or refractory hypertension. However, little is known about the safety of α-blockers in patients treated by hemodialysis. We analyzed 5,149 patients receiving hemodialysis in Japan who were receiving antihypertensive drugs from the Japan Dialysis Outcomes and Practice Patterns Study. The results showed no significant increase in the risk of fractures, falls, or deaths for patients using α-blockers compared with those who did not, suggesting that α-blockers may be safely prescribed for patients receiving hemodialysis who need to lower their blood pressure.

Long-Term Effect of Denosumab on Bone Disease in Patients with CKD

BACKGROUND

The effect of long-term denosumab therapy and of denosumab discontinuation on the cortical bone of the hip regions in dialysis patients has not been studied.

METHODS

This retrospective study investigated the cortical and trabecular compartments and estimated strength indices of the hip region, obtained using 3D-SHAPER software, after a maximum of 5 years of denosumab therapy in 124 dialysis patients. A Wilcoxon signed-rank test was used to identify the differences in each parameter before and after denosumab initiation. Similarly, we investigated the changes in these parameters after denosumab discontinuation in 11 dialysis patients.

RESULTS

Integral and trabecular volumetric bone mineral densities (BMD) were significantly lower at the start of denosumab therapy than those in 1 year before denosumab initiation. After starting denosumab, areal BMD (median change +7.7% [interquartile range (IQR), +4.6 to +10.6]), cortical volumetric BMD (median change +3.4% [IQR, +1.0 to +4.7]), cortical surface BMD (median change +7.1% [IQR, +3.4 to +9.4]), and cortical thickness (median change +3.2% [IQR, +1.8 to +4.9]) showed a significantly higher trend for 3.5 years, which then stabilized at a higher value compared with baseline. A similar trend in the trabecular volumetric BMD (median change +9.8% [IQR, +3.8 to +15.7]) was observed over 2.5 years, with a higher value maintained thereafter. The whole area of the hip region improved after denosumab therapy. Similar trajectories were also found in the estimated strength indices. Conversely, at 1 year after denosumab discontinuation, these 3D parameters and estimated strength indices tended to largely worsen. The lateral aspect of the greater trochanter was the most pronounced location showing volumetric BMD loss.

CONCLUSIONS

The BMD of both cortical and trabecular components in the hip region was significantly higher after starting denosumab therapy. However, these measurements exhibited a trend of declining substantially after the discontinuation of denosumab.

Risk factors for blood vessel rupture during vascular access intervention therapy for hemodialysis patients

Blood vessel rupture is a major complication associated with vascular access intervention therapy (VAIVT). However, information regarding the risk factors for ruptures related to VAIVT is limited. The purpose of this study was to investigate the risk factors for rupture during VAIVT. This was a single-center, retrospective observational study. Demographic, clinical, anatomical, and VAIVT procedure variables were reviewed and analyzed using multivariate logistic regression. The 211 patients included in the study underwent 628 VAIVT procedures from November 2019 to December 2021, and 20 blood vessel ruptures occurred. Patients with ruptures had significantly lower BMI (p = 0.043), shorter access vintage(p = 0.017), underwent VAIVT for the first time (p = 0.006), and had lower blood flow quantity (p = 0.005), lower brachial artery flow volume (p = 0.018), and higher resistance index (p = 0.011). The multivariate logistic regression revealed that receiving VAIVT for the first time (OR 5.95, 95%CI 1.01-34.84; p = 0.048) and high resistance index (OR 1.86, 95%CI 1.01-3.16; p = 0.02) were significantly associated with a high risk for rupture. Furthermore, receiver operating characteristic curve analysis to assess the sensitivity-specificity profiles of the resistance index for ruptures showed that the optimal threshold was 0.70 (sensitivity/specificity, 0.69/0.70). Heightened surveillance during vascular access intervention therapy is warranted, especially in patients undergoing VAIVT for the first time or patients with a high resistance index (> 0.70).

Secular trends in incidence and seasonal variation of distal radius fracture among children: A nationwide study based on the Swedish National Patient Register 2002-2016

BACKGROUND AND PURPOSE

Although distal radius fracture (DRF) is the most common fracture type in children, research on its seasonality across different age groups is limited. We investigated secular trends in incidence and seasonal variation of pediatric DRF based on Swedish nationwide population database.

PATIENTS AND METHODS

In this observational study, data for all children aged <18 years in Sweden with DRF defined by ICD-codes were analyzed for each month and each year during 2002-2016 using the Swedish National Patient Register. The general population counts for each age and sex-category were acquired to evaluate population at risk for each period. We calculated the age standardized and sex specific annual incidence rates, seasonal incidence rates, and monthly incidence rates and analyzed the seasonal variation in the mechanisms of injury.

RESULTS

A total of 155,891 DRF cases were identified. The age standardized and sex specific incidence rate was 531 (95%CI 528-533) per 100,000 patient years at risk. Fracture risk was highest during summer and lowest in the winter. The highest seasonal variation was observed among boys 2- < 5 years. The crude incidence rate and the age-standardized incidence rates in winter significantly decreased between 2002 and 2016 (annual percentage change, -2 %).

INTERPRETATION

We found significant seasonal variation in DRF among all age groups in Swedish children. The findings can help in developing strategies to prevent fractures as well as in allocating medical and social resources.

Bilateral renal subcapsular hematoma caused by polyarteritis nodosa: a case report

Polyarteritis nodosa, which is a systemic vasculitis of small- and medium-sized arteries, can cause arterial aneurysms in various organs, sometimes resulting in aneurysm rupture and hemorrhage. A kidney is one of the major targets of polyarteritis nodosa. Here, we report a 73-year-old woman who presented with sudden-onset high fever, diarrhea, and renal injury with bilateral renal subcapsular hematoma shown on contrast-enhanced computed tomography scan. She did not have trauma and significant medical history other than breast cancer in remission. Serological and immunological tests except for anti-Sjögren's syndrome-A and anti-Sjögren's syndrome-B were all negative. Digital subtraction angiography revealed bilateral intrarenal micro aneurysms, which allowed us to diagnose the patient with polyarteritis nodosa. As continuous monitoring of bilateral intrarenal hematoma by ultrasonography and computed tomography scan did not detect progression of intrarenal hemorrhage and extra renal hematoma, transcatheter arterial embolization and nephrectomy were not performed. Although hemodialysis therapy was required temporarily for acute kidney injury with anuria, her general condition and kidney function remarkably improved after receiving systemic immunosuppressive therapy with corticosteroids and cyclophosphamide. In conclusion, this is a rare case of polyarteritis nodosa manifesting as spontaneous bilateral subcapsular renal hemorrhage with deteriorated renal function, which was successfully treated with immunosuppressive therapy.

Secular trends in hip fracture incidence and subsequent mortality in dialysis patients and the general population in Sweden

BACKGROUND

Declining trends of hip fracture incidence in dialysis patients were reported from USA and Japan while studies from Europe are lacking. We investigated trends in hip fracture incidence and subsequent mortality in Swedish dialysis patients, comparing with the Swedish general population.

METHODS

We used the population-based Swedish national database of fractures and the Swedish National Renal Registry to retrieve data on hip fractures incidence and subsequent mortality for years 2007-2016. Trends for age-standardized hip fracture incidence rate (ASR_{hip fracture}) and age-standardized 30-day (ASMR_30day) and 180-day (ASMR_180day) post-hip fracture mortality rate in Swedish general population were evaluated by joinpoint regression analysis. Standardized incidence ratios of hip fracture (SIR) and standardized mortality ratios (SMR) were calculated for Swedish dialysis patients.

RESULTS

In the general population, ASR_{hip fracture} declined significantly: in women from 2007 and in men from 2009. In dialysis patients, SIR was 3-5 times higher compared to the general population and declined over time in women but not in men. In general population, mortality (ASMR_30day and ASMR_180day) declined significantly in women and men. In dialysis patients, post-fracture mortality (SMR, mainly for 180-day mortality) remained two-fold higher than in general population with no consistent trend towards improvement.

CONCLUSIONS

Hip fracture incidence and subsequent mortality fell among women and men in the Swedish general population. In dialysis patients, hip fracture incidence declined in women but not in men while post-fracture mortality did not improve, and the incidence and subsequent mortality remained 3 to 5-fold and 2-fold higher than in the general population.

Sparing effect of peritoneal dialysis vs hemodialysis on BMD changes and its impact on mortality

INTRODUCTION

Bone loss in end stage renal disease (ESRD) patients associates with fractures, vascular calcification, cardiovascular disease (CVD) and increased mortality. We investigated factors associated with changes of bone mineral density (ΔBMD) during the initial year on dialysis therapy and associations of ΔBMD with subsequent mortality in ESRD patients initiating dialysis.

MATERIALS AND METHODS

In 242 ESRD patients (median age 55 years, 61% men) starting dialysis with peritoneal dialysis (PD; n = 138) or hemodialysis (HD; n = 104), whole-body dual-energy X-ray absorptiometry (DXA), body composition, nutritional status and circulating biomarkers were assessed at baseline and 1 year after dialysis start. We used multivariate linear regression analysis to determine factors associated with ΔBMD, and fine and gray competing risk analysis to determine associations of ΔBMD with subsequent mortality risk.

RESULTS

BMD decreased significantly in HD patients (significant reductions of BMD_total and BMD_{leg, trunk, rib, pelvis and spine}) but not in PD patients. HD compared to PD therapy associated with negative changes in BMD_{total (β=- 0.15)}, BMD_{head (β=- 0.14)}, BMD_{leg (β=- 0.18)} and BMD_{trunk (β=- 0.16)}. Better preservation of BMD associated with significantly lower all-cause mortality for ΔBMD_total (sub-hazard ratio, sHR, 0.91), ΔBMD_head (sHR 0.91) and ΔBMD_leg (sHR 0.92), while only ΔBMD_head (sHR 0.92) had a beneficial effect on CVD-mortality.

CONCLUSIONS

PD had beneficial effect compared with HD on BMD changes during first year of dialysis therapy. Better preservation of BMD, especially in bone sites rich in cortical bone, associated with lower subsequent mortality. BMD in cortical bone may have stronger association with clinical outcome than BMD in trabecular bone.

Incidence of Fractures Before and After Dialysis Initiation

Fractures are common in dialysis patients, but little is known about the trajectory of incidence rates of different types of fractures before and after dialysis initiation. To address this, we investigated the incidence of major fractures before and after dialysis initiation. We performed a retrospective statistical analysis using the Swedish Renal Registry of 9041 incident dialysis patients (median age 67 years, 67% men) starting dialysis 2005 through 2015 to identify major fractures (hip, spine, humerus, and forearm) occurring during the dialysis transition period from 1 year before until 1 year after dialysis initiation. Using flexible parametric hazard models and the Fine-Gray model, we estimated adjusted fracture incidence rates and predictors of major fractures. We identified 361 cases with primary diagnosis of major fracture, of which 196 (54%) were hip fractures. The crude incidence rate of major fractures before dialysis initiation was 17 per 1000 patient-years (n = 157) and after dialysis initiation it was 24 per 1000 patient-years (n = 204). The adjusted incidence rate of major fractures began to increase 6 months before dialysis initiation, and then stabilized at a higher rate after 1 year. The adjusted incidence rate of hip fractures started to increase sharply 3 months before dialysis initiation, peaked at initiation, and declined thereafter. In contrast, the adjusted incidence rate of non-hip fractures was stable during the transition period and gradually increased over time. Higher age, female sex, and history of previous major fractures were associated with increased fracture incidence both before and after dialysis initiation. We conclude that the incidence of major fractures, especially hip fractures, start to rise 6 months before initiation of dialysis therapy, indicating that heightened surveillance with implementation of preventive measures to avoid fractures is warranted during the transition period to dialysis. © 2020 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Fractures after kidney transplantation: Incidence, predictors, and association with mortality

BACKGROUND

Major fractures (MF) are associated with increased mortality in the general population and represent an even higher risk in patients with chronic kidney disease. We investigated incidence, predictors and clinical outcomes associated with first MF (MF_first) following kidney transplantation (KT).

METHODS

We used the Swedish National Renal Registry of 3992 first KT recipients (2005-2016) (median age 53 years, 65% men) and identified all MF_first in hip, spine, humerus and forearm following KT. We estimated incidence rates and predictors of MF_first using flexible parametric hazard models and Fine-Gray analysis accounting for competing risk of death, and risk of all-cause mortality following MF_first using Cox proportional hazards models with fracture as time-varying exposure.

RESULTS

During median follow-up of 4.8 years (IQR 2.2-7.9 years), there were 279 fractures of which 139 were forearm fractures. The crude incidence rate of MF_first (n = 279) was 13.5/1000 patient-years and that of hip fractures (n = 69) 3.4/1000 patient-years. The multivariate-adjusted fracture incidence rates were highest during the first 6 months following KT, and 86% higher in women than in men. High age, female sex, previous history of MF, diabetes nephropathy, pretransplant dialysis therapy and acute rejection were associated with increased risk for MF_first, whereas pre-emptive KT was associated with lower risk of MF_first. Spline curves showed markedly higher impact of higher age on risk of MF_first in women than in men. MF_first (n = 279) independently predicted increased all-cause mortality risk (hazard ratio, HR, 1.78(95%CI 1.35-2.36)). Among MF_first, with humerus fracture as reference, hip fracture (HR, 4.68(95%CI 1.56-14.06)) and spine fracture (HR, 4.02(95%CI 1.19-13.54)), but not forearm fracture (HR, 1.17 (95%CI 0.38-3.53)), were associated with increased all-cause mortality risk.

CONCLUSIONS

The initial 6 months following kidney transplantation is a high-risk period for MF. Among MF, hip fracture and spine fracture associate with substantially increased all-cause mortality risk.

Fractures and their sequelae in non-dialysis-dependent chronic kidney disease: the Stockholm CREAtinine Measurement project

Introduction

People undergoing maintenance dialysis are at high risk for fractures, but less is known about fracture incidence and associated outcomes in earlier stages of chronic kidney disease (CKD).

Methods

We conducted an observational analysis from the Stockholm Creatinine Measurement project, a Swedish health care utilization cohort during 2006–11. We identified all adults with confirmed CKD Stages 3–5 and no documented history of fractures and extracted information on comorbid history, ongoing medication, cardiovascular events and death. We studied incidence rates of fractures (overall and by location), with the estimated glomerular filtration rate (eGFR) as time-dependent exposure. We then studied hazard ratios [HRs and 95% confidence intervals (CIs)] for the events of death and major adverse cardiac events (MACE) using Cox regression with fracture as time-varying exposure.

Results

We identified 68 764 individuals with confirmed CKD (mean age 79 years, 56% women). During a median follow-up of 2.7 years, 9219 fractures occurred, of which 3105 were hip fractures. A more severe CKD stage was associated with a higher risk of fractures, particularly hip fractures: compared with CKD Stage 3a, the adjusted HR was 1.10 (95% CI 1.02–1.19), 1.32 (1.17–1.49) and 2.47 (1.94–3.15) for CKD Stage 3b, 4 and 5, respectively. Spline curves suggested a linear association with fracture risk with an eGFR <30 mL/min/1.73 m². Compared with non-fracture periods, incident fracture was associated with a 4-fold increased mortality within 90 days [HR 4.21 (95% CI 3.95–4.49)]. The risk remained elevated beyond 90 days [HR 1.47 (95% CI 1.40–1.54)] and was stronger after hip fractures. Post-fracture MACE risk was also highest in the first 90 days [HR 4.02 (95% CI 3.73–4.33)], particularly after hip fractures, and persisted beyond 90 days [HR 1.20 (95% CI 1.10–1.30)].

Conclusion

Our findings highlight the commonness of fractures and the increased risk for subsequent adverse outcomes in CKD patients. These results may inform clinical decisions regarding post-fracture clinical surveillance and fracture prevention strategies.

P1409HIP FRACTURE TRENDS IN SWEDISH GENERAL POPULATION AND DIALYSIS PATIENTS

Background and Aims

Hip fracture incidence rate is higher in dialysis patients than in general population. We investigated and compared temporal changes in age-standardized hip fracture incidence rate (ASRhip fracture) 2007-2016 in men and women in the dialysis population and in the general population.

Method

We used the population-based Swedish national database of fractures and the Swedish Renal Registry of ESRD patients to retrieve data on ASRhip fracture in the general population and among dialysis patients. The average annual percent change of the hip fracture incidence trend was evaluated by join-point regression analysis according to gender in the two databases.

Results

ASRhip fracture was about three times higher in Swedish dialysis patients as compared to the Swedish general population. In dialysis patients, rates have steadily declined during the recent decade when assessed in both sexes combined, and when analysed in women and men separately. A similar trend was also seen in the general population; however, the rate of decline was steeper in dialysis patients than in the general population. The most recent data on ASRhip fracture (for 2016) show that ASRhip fracture was similar among female and male dialysis patients whereas ASRhip fracture in the general population was higher in women than in men.

Conclusion

Hip fracture incidence is declining in the general population and even more so in dialysis patients. In contrast to the general population where hip fracture incidence in 2016 is higher among women than in men, there was no such difference between the two sexes among dialysis patients.

P0887MAJOR OSTEOPOROTIC FRACTURES AFTER KIDNEY TRANSPLANTATION: INCIDENCE, PREDICTORS AND ASSOCIATION WITH MORTALITY

Background and Aims

Major osteoporotic fractures (MOF) are associated with increased morbidity and mortality in ESRD patients. We investigated incidence, predictors and clinical outcomes associated with first MOF (MOFfirst) following kidney transplantation (KT).

Method

In Swedish Renal Registry of 3992 first KT recipients (2005 -2016) (age 53 years, 65% men), we identified all MOFfirst in hip, spine, humerus and forearm following KT. We estimated incidence rates and predictors of MOFfirst using flexible parametric hazard models and Fine-Gray analysis accounting for competing risk of death, and risk of all-cause mortality following MOFfirst using Cox proportional hazards models with fracture as time-varying exposure.

Results

During median follow-up of 4.8 years (IQR 2.2-7.9 years), there were 279 fractures of which 139 were forearm fractures. The crude incidence rate of MOFfirst (n=279) was 14/1000 patient-years and that of hip fractures (n=69) 3/1000 patient-years. The multivariate-adjusted fracture incidence rates were highest during the first 6 months following KT, and two-fold increased among women. High age, female sex, previous history of MOF, diabetes nephropathy, pretransplant dialysis therapy and acute rejection were associated with increased risk for MOFfirst, whereas pre-emptive KT was associated with lower risk of MOFfirst. Spline curves showed that impact of age in women on MOFfirst was markedly higher than in men. MOFfirst (including all cases) independently predicted increased all-cause mortality (hazard ratio, HR, 1.78(95%CI 1.35-2.36)). Among MOFfirst, hip fracture (HR, 4.68(95%CI 1.56-14.06)) and spine fracture (HR, 4.02(95%CI 1.19-13.54)) were significantly associated with increased all-cause mortality.

Conclusion

The initial six months following kidney transplantation is a high-risk period for major osteoporotic fractures, especially forearm fractures. MOFs, especially hip and spine fracture, are associated with increased mortality.

Bone mineral density and mortality in end-stage renal disease patients

Osteoporosis characterized by low bone mineral density (BMD) as assessed by dual-energy X-ray absorptiometry (DXA) is common among end-stage renal disease (ESRD) patients and associates with high fracture incidence and high all-cause mortality. This is because chronic kidney disease-mineral bone disorders (CKD-MBDs) promote not only bone disease (osteoporosis and renal dystrophy) but also vascular calcification and cardiovascular disease. The disturbed bone metabolism in ESRD leads to 'loss of cortical bone' with increased cortical porosity and thinning of cortical bone rather than to loss of trabecular bone. Low BMD, especially at cortical-rich bone sites, is closely linked to CKD-MBD, vascular calcification and poor cardiovascular outcomes. These effects appear to be largely mediated by shared mechanistic pathways via the 'bone-vascular axis' through which impaired bone status associates with changes in the vascular wall. Thus, bone is more than just the scaffolding that holds the body together and protects organs from external forces but is-in addition to its physical supportive function-also an active endocrine organ that interacts with the vasculature by paracrine and endocrine factors through pathways including Wnt signalling, osteoprotegerin (OPG)/receptor activator of nuclear factor-κB (RANK)/RANK ligand system and the Galectin-3/receptor of advanced glycation end products axis. The insight that osteogenesis and vascular calcification share many similarities-and the knowledge that vascular calcification is a cell-mediated active rather than a passive mineralization process-suggest that low BMD and vascular calcification ('vascular ossification') to a large extent represent two sides of the same coin. Here, we briefly review changes of BMD in ESRD as observed using different DXA methods (central and whole-body DXA) at different bone sites for BMD measurements, and summarize recent knowledge regarding the relationships between 'low BMD' and 'fracture incidence, vascular calcification and increased mortality' in ESRD patients, as well as potential 'molecular mechanisms' underlying these associations.

P0714RELATIONSHIP BETWEEN BIOLOGICAL AGE ESTIMATED BY SKIN AUTOFLUORESCENCE, CHRONOLOGICAL AGE, AND MORTALITY IN CHRONIC KIDNEY DISEASE

Background and Aims

While chronological age associates with increased risk of death, there is a quest for markers of biological age in chronic kidney disease (CKD) that better reflect accumulation of tissue and cellular damage, which could contribute to shorter life span. Skin autofluorescence (SAF) is a biomarker for accumulation of advanced glycation end products in skin that associate with chronological age and with factors that may increase mortality risk. However, the predictive capacity of SAF for mortality has not been fully elucidated in CKD. We have investigated the relationship between biological age calculated by SAF, chronological age and all-cause mortality in patients with CKD stage 5.

Method

In a cohort of 199 CKD5 patients (non-dialysis CKD5, n=100, hemodialysis, n=27 and peritoneal dialysis, n=72; median age 66 years, 34% females, 21% diabetes (DM), 20% cardiovascular disease (CVD), and 34% malnourished), we calculated biological age by a formula based on SAF measurements using the AGE Reader. Framingham risk score, coronary artery calcium score, the heart rate-corrected augmentation index, body composition, nutritional status, handgrip strength, and various biochemical markers (hemoglobin, albumin, creatinine, intact-parathyroid hormone, triglyceride, cholesterol, HDL-cholesterol, high-sensitivity C-reactive protein (hsCRP), and interleukin (IL)-6) were recorded at baseline. During median follow-up of 38 months, 34 patients died, and 51 patients underwent renal transplantation. We analyzed spline curves showing sub-distribution hazard risk (sHR) for all-cause mortality with biological age calculated by SAF and chronological age by the Fine and Gray competing risk analysis.

Results

There was a significant association between biological age calculated by SAF and chronological age (rho=0.48; p&lt;0.001). IL-6 and hsCRP were positively associated both with biological age according to SAF measurement (IL-6: rho=0.34, p&lt;0.001; n=155 and hsCRP: rho=0.31, p&lt;0.001; n=199) and chronological age (IL-6: rho=0.47, p&lt;0.001; n=155 and hsCRP: rho=0.40, p&lt;0.001; n=199). The multivariate spline curve showing sHR for all-cause mortality associated positively with chronological age (sHR: 1.04, p=0.035) and biological age calculated by SAF (sHR: 1.01, p=0.048) when adjusted for sex, DM, CVD, nutritional status, 1-standard deviation increase of hsCRP, and CKD5 groups.

Conclusion

All-cause mortality risk increased linearly with higher chronological age and SAF-estimated biological age - and with similar magnitude of sHR for the two - suggesting that prediction of mortality risk based on SAF is not superior compared to chronological age in CKD. We conclude that biological age calculated by SAF and chronological age are equally robust predictors of clinical outcomes in CKD; however, both indices are influenced by the inflammatory status.

P0528RENOPROTECTIVE EFFECT OF IL-34 INHIBITION ON CISPLATIN-INDUCED NEPHROTOXICITY IN MICE

Background and Aims

Interleukin (IL)-34, a macrophage (Mø) mediator, is expressed by tubular epithelial cells (TECs). However, the influence of IL-34 on TECs injury has not been fully elucidated. We investigated the physiological properties of IL-34 on TECs damage caused by cisplatin-nephrotoxicity (CP-N).

Method

7-week-old male C57BL/6 (B6) mice (n=16) were fasted for 8 hours and then induced CP-N by intraperitoneal injection (IP) of CP (25 mg/kg) on day 0. Groups of animals were given either anti-mouse IL-34 antibody (CP+anti-IL-34 Ab, 400 ng/kg, n=8) or vehicle (CP+V, equal volume of saline, n=8) daily by IP from day -1 to day 2. Three age-matched male B6 mice were used as normal control (NC). All mice were sacrificed on day 3. In addition, mouse renal proximal TECs (MRTEpiC) were cultured to analyze the inhibitory effects of IL-34 on CP-induced TEC apoptosis. Cells were stimulated with CP (2 μg/mL), then treated with or without anti-IL-34 Ab (1000 pg/mL).

Results

Compared to the NC, CP+V mice exhibited marked acute kidney injury (AKI) and upregulated expression of IL-34 and its two receptors, cFMS and PTP-ζ. Compared to the vehicle treatment, anti-IL-34 Ab treatment significantly suppressed the intrarenal expression levels of IL-34 and its two receptors in CP-N mice; it also significantly suppressed serum IL-34 levels (72.1 ± 5.6 vs. 40.4 ± 7.5 pg/mL, p=0.013). Additionally, treatment with anti-IL-34 Ab significantly improved serum Cr levels (1.3 ± 0.2 vs. 0.7 ± 0.1 mg/mL, p=0.033), ameliorated tubulointerstitial injury (numbers of casts/HPF: 11.9 ± 2.6 vs. 6.5 ± 1.8, p=0.048), and suppressed the number of F4/80+ Mø (17.5 ± 2.7 vs. 11.1 ± 1.1/HPF, p=0.041) and TUNEL+ apoptotic cells (29.2 ± 4.9 vs. 16.7 ± 2.7/HPF, p=0.036) in CP-N mice. The renal cortical transcript levels of Kim-1, MIP-1/CCL3, TNF-α, and Bax were significantly lower in the CP+anti-IL-34 Ab mice than in the CP+V mice. Furthermore, the CP+anti-IL-34 Ab mice showed significantly less renal infiltration of CD11b+F4/80+TNF-α+ cells. In vitro, stimulation with CP induced the expression of IL-34 and its two receptors in MRTEpiC. Treatment with anti-IL-34 Ab significantly suppressed CP-induced caspase-3 and Bax expression with degradation of ERK1/2 phosphorylation in the damaged MRTEpiC.

Conclusion

IL-34 secreted from damaged TECs was involved in the progression of CP-N. Inhibition of IL-34 with neutralizing antibody directly prevented CP-induced TEC apoptosis by inhibiting the phosphorylation of ERK1/2. Blocking of IL-34 might suppressed proliferation of cytotoxic Mø, which indirectly led to the attenuation of CP-N. Thus, IL-34 represents a potential as therapeutic target for AKI with TECs injury.

P0673INVERSE ASSOCIATION OF TRANSFERRIN SATURATION WITH MORTALITY RISK IN CHRONIC KIDNEY DISEASE

Background and Aims

Transferrin saturation (TSAT) is an indicator of iron deficiency or overload, but its relationship with mortality in patients with different stages of chronic kidney disease (CKD) is unclear. We investigated the association of TSAT with mortality in CKD patients.

Method

In 479 CKD patients (97 CKD3-4 patients, 298 CKD5 non-dialysis patients and 84 peritoneal dialysis patients; median age 58 years, 67% males, 33% cardiovascular disease, CVD, and 29% diabetes), biomarkers of iron status (plasma iron, TSAT, transferrin and ferritin), systemic inflammation (high sensitivity C-reactive protein, hsCRP, and interleukin-6, IL-6) and nutritional status were assessed. During median follow-up of 35.6 months, 139 (29%) patients died, and 176 (37%) patients underwent renal transplantation. Patients were stratified into low (n=157) and high (n=322) TSAT tertile groups. All-cause and CVD mortality risk were analyzed with competing risk regression with renal transplantation as competing risk.

Results

TSAT [median 23% (IQR 17-30%)] was negatively associated with presence of DM and CVD, body mass index, hsCRP, IL-6, Framingham´s CVD risk score (FRS), erythropoietin resistance index (ERI) and iron supplementation, and positively associated with hemoglobin, ferritin and s-albumin. In competing risk analysis, low tertile of TSAT was independently associated with increased all-cause mortality risk (sHR=1.50, 95%CI 1.05-2.14) after adjusting for CKD stages, 1-SD of FRS, 1-SD of hemoglobin, 1-SD of hsCRP, 1-SD of ESA dose and iron supplementation (Figure 1).

Conclusion

TSAT was inversely associated with mortality risk in CKD patients. When evaluating clinical outcomes of CKD patients, iron status using TSAT as a predictive marker, should be considered.

SO072INCIDENCE OF FRACTURES BEFORE AND AFTER DIALYSIS INITIATION AMONG INCIDENT DIALYSIS PATIENTS

Background and Aims

The incidence of fractures is markedly higher in dialysis patients than in pre-dialysis patients, but it is not clear to what extent the initiation of dialysis as such is associated with accelerated fracture incidence or if fracture rates are already increasing prior to dialysis start among incident dialysis patients. Here we investigated the temporal pattern of occurrence of a first major osteoporotic fracture (MOF) among incident dialysis patients in the pre-dialysis period and in the period following dialysis initiation.

Method

We analyzed data from Swedish Renal Registry (SRR) and identified 9041 incident dialysis patients (2005 -2015; age 67 years, 67% men). We identified all first MOF (MOFfirst) in hip, spine, humerus and forearm during 12 months before and after dialysis initiation. Using flexible parametric hazard models and Fine-Gray analysis accounting for competing risk of death and renal transplantation, we estimated adjusted fracture incidence rates and predictors of MOFfirst.

Results

During the whole follow-up period, there were 361 fractures including 196 hip fractures. The crude incidence rate of MOFfirst (n=157) before dialysis initiation was 17/1000 patient-years and after initiation of dialysis the incidence rate of MOFfirst increased to 24/1000 patient-years. Overall the adjusted MOFfirst incidence rates increased from 6 months before initiation of dialysis, fluctuated, and stabilized at a higher rate than that of the baseline rate after 12 months. The adjusted hip fracture rate rose steeply 3 months before dialysis initiation, declined 3 months after dialysis initiation, fluctuated, and then became stabilized. On the contrary, the adjusted incidence rates of other fractures, i.e., non-hip fractures, appeared to be stable all the time, before as well as after initiation of dialysis. Female gender, higher age and previous history of MOF had a negative impact on fracture incidence rates before and after dialysis initiation.

Conclusion

We conclude that the incidence of MOFfirst is increasing already from 6 months prior to dialysis initiation among incident dialysis patients, and that there is a further increase following dialysis initiation. For hip fracture, which was the most common MOF, the temporal pattern of incidence rates was compressed to a high risk period lasting from 3 months before to 3 months after dialysis initiation, underlining the need of increased attention to prevent hip fractures in incident dialysis patients during this critical period.

P1389MAJOR OSTEOPOROTIC FRACTURES AFTER INITIATION OF DIALYSIS: INCIDENCE, PREDICTORS AND ASSOCIATION WITH MORTALITY

Background and Aims

Major osteoporotic fractures (MOF) are common in dialysis patients. We investigated incidence, predictors and clinical outcomes associated with first MOF occurring after initiation of dialysis (MOFfirst).

Method

In Swedish Renal Registry of 9714 incident (2005 -2016) dialysis patients (median age 68 years, 67% men), we identified all MOFfirst in hip, spine, humerus and forearm. Using flexible parametric hazard models and Fine-Gray analysis, we estimated incidence, mortality rates and predictors of MOFfirst, and, in time-dependent analysis, risk of all-cause and cardiovascular disease (CVD) mortality following MOFfirst.

Results

During median follow-up of 2.2 years, the crude incidence rate of MOFfirst (n=835) was 24/1000 patient-years (pt-yrs) and that of hip fractures (n=470) 13/1000 pt-yrs. The multivariate-adjusted fracture incidence rates increased gradually after dialysis initiation and were 47% higher among women. Female sex, higher age, presence of comorbidities, and previous history of MOF (MOFprevious) were associated with increased risk for MOFfirst, whereas peritoneal dialysis as compared to hemodialysis was associated with decreased fracture risk. The adjusted fracture incidence rate of MOFfirst during the first 90 days following dialysis initiation was higher in patients with MOFprevious than in those without MOFprevious. MOFfirst independently predicted increased all-cause mortality (sub-distribution hazard ratio, sHR, 1.67(95%CI 1.47-1.91) and CVD-related mortality (sHR 1.49 (95%CI 1.22-1.84). Adjusted mortality rate following hip fractures was higher than for other types of MOF. Spline curves showed that mortality following MOFfirst was highest during the first 6 months of follow-up.

Conclusion

Major osteoporotic fractures are common and associated with increased mortality in incident dialysis patients.

P0669HIGH ESTIMATED PHENOTYPIC AGE ASSOCIATES WITH WORSE CLINICAL OUTCOME IN CHRONIC KIDNEY DISEASE PATIENTS

Background and Aims

Ageing represents the greatest risk factor contributing to increased morbidity and mortality in most chronic diseases; it encompasses numerous biological changes resulting in declining physiological function and increasing burden of disease. Whether new biomarkers of ageing and risk scores for predicting physiological outcomes, including mortality, are applicable and more accurate than chronological age in patients with chronic kidney disease (CKD) is not clear. So far, the DNA methylation (DNAm) PhenoAge biomarker of ageing (Levine et al. Aging 2018) has not been tested in CKD. While we had no access to DNAm data, we applied the phenotypic age estimate proposed by Levine et al., which was included in their calculations of DNAm PhenoAge, and tested the relationship between estimated phenotypic age (ePhenoAge) and chronological age, respectively, with all-cause mortality in patients with CKD.

Method

In a cohort of 333 CKD patients (stage 1, n=78; stage 3-4, n=64; and stage 5, n=191) with median age 56 years, 43% females, 24% diabetes (DM), 25% cardiovascular disease (CVD), and 22% malnourished, we estimated age by ePhenoAge, using a formula with calculations based on nine biomarkers and chronological age, and compared this age index with chronological age. Framingham risk score, body composition, nutritional status, handgrip strength, and various biochemical markers (white blood cells, mean cell volume, hemoglobin, albumin, creatinine, glucose, calcium, alkaline phosphatase, intact-parathyroid hormone, triglyceride, cholesterol, HDL-cholesterol, high-sensitivity C-reactive protein (hsCRP), and interleukin (IL)-6) were recorded. During a median follow-up period of 52 months, 65 patients died, and 111 patients underwent renal transplantation. We used spline curve to illustrate sub-distribution hazard risk (sHR) for all-cause mortality versus increasing ePhenoAge and chronological age respectively as obtained by the Fine and Gray competing risk analysis.

Results

In univariate analyses, IL-6 (rho=0.49, p&lt;0.001; n=268) and hsCRP (rho=0.37, p&lt;0.001; n=333) were significantly correlated with ePhenoAge. The ePhenoAge remained significantly associated with hsCRP (p=0.02) when adjusted for sex, DM, CVD, nutritional status and CKD stages. The spline curves showing sHR for all-cause mortality derived from multivariate competing risk analysis and adjusted for sex, presence of DM and CVD, hsCRP, nutritional status and CKD stages, showed increased mortality risk with higher chronological age (sHR: 1.08, p&lt;0.001). In contrast, the association of mortality with higher ePhenoAge (sHR: 1.04, p=0.06) was of borderline statistical significance.

Conclusion

All-cause mortality risk was associated with increasing chronological age in competing risk analysis with adjustments of confounders. A similar trend was observed for ePhenoAge, a finding which to a large extent may be explained by the inflammatory status of the study subjects. However, contrary to expectations, ePhenoAge was not as powerful as chronological age in predicting mortality, underlining that our knowledge about factors influencing phenotypic age in CKD patients is still limited. This should motivate further study of the potential role of other estimates of biological age in CKD.

P1399SPARING EFFECT OF PERITONEAL DIALYSIS VS HEMODIALYSIS ON CHANGE OF BONE MINERAL DENSITY EVALUATED BY WHOLE-BODY DXA AFTER INITIATION OF DIALYSIS THERAPY AND ITS IMPACT ON CLINICAL OUTCOME

Background and Aims

Bone loss is associated with progression of cardiac calcification and increased mortality in end stage renal disease (ESRD) patients but the relations and underlying causes are unclear. We investigated factors associated with changes of bone mineral density (BMD) during the first year after initiation of dialysis and the association between BMD changes and subsequent mortality in ESRD patients.

Method

In a prospective study of 242 ESRD patients (median age 55 years, 61% men) starting dialysis, total BMD and BMD at specific bone sites (including seven subregions: head, arms, legs, trunk, hip, pelvis and spine) was assessed by whole body dual-energy X-ray absorptiometry (DXA) at baseline and one year after dialysis start. Framingham cardiovascular disease (CVD) risk score, body composition, nutritional status, handgrip strength, various biochemical biomarkers (white blood cell, hemoglobin, albumin, creatinine, calcium, phosphate, intact parathyroid hormone, triglyceride, cholesterol, HDL cholesterol and high-sensitivity C-reactive protein) were recorded. We used multivariate linear regression analysis for BMD change analysis. We followed patients from 12 months after initiating of dialysis until renal transplantation, death or end of 60 months follow-up. During follow-up, 59 patients (24%) died due to CVD (n=33) or other causes (n=26) and 95 patients (39%) underwent renal transplantation. Fine and Gray competing risk analysis was used to ascertain associations of BMD changes with all-cause and CVD-related mortality.

Results

From baseline to one year after initiation of dialysis, there was a significant decrease of BMDtotal and BMDleg, trunk, rib, pelvis and spine in hemodialysis (HD) patients, whereas no difference was seen in peritoneal dialysis (PD) patients. In multivariate linear regression analysis adjusting for several confounders, HD therapy - compared to PD therapy - was significantly associated with negative changes in BMDtotal (β=-0.15), BMDhead (β=-0.14), BMDleg (β=-0.18) and BMDtrunk (β=-0.16). The direction and extent of changes in BMD, i.e. increase of BMD, associated with statistically significant lower all-cause mortality risk for BMDtotal (sHR, 0.91), BMDhead (sHR 0.91) and BMDleg (sHR 0.92), while for CVD-mortality a significant association with BMD changes was found only for changes in BMDhead (sHR 0.92).

Conclusion

In patients starting on dialysis, PD therapy appeared to have a beneficial effect on BMD changes as compared to HD during the first year of dialysis therapy. This difference may have implications for clinical outcomes as the degree of bone loss was associated with subsequent mortality. Changes towards increased BMDtotal, BMDhead and BMDleg associated with lower all-cause mortality. For head region – which is known as a cortical bone rich site – positive BMD change associated also with lower CVD mortality suggesting that increase or maintenance of BMD of cortical bone rich sites may have stronger association with clinical outcome in ESRD than BMD of trabecular bone.

Major fractures after initiation of dialysis: Incidence, predictors and association with mortality

BACKGROUND

Major fractures (MF) are common in dialysis patients. We investigated incidence, predictors and clinical outcomes associated with first MF occurring after initiation of dialysis (MF_first).

METHODS

In Swedish Renal Registry of 9714 incident (2005-2016) dialysis patients (age 68 years, 67% men), we identified all MF_first in hip, spine, humerus and forearm. Using flexible parametric hazard models and Fine-Gray analysis, we estimated incidence, mortality rates and predictors of MF_first, and, in time-dependent analysis, risk of all-cause and cardiovascular disease (CVD) mortality following MF_first.

RESULTS

During median follow-up of 2.2 years, the crude incidence rate of MFfirst (n = 835) was 23.7/1000 patient-years and that of hip fractures (n = 470) 13.3/1000 patient-years. The multivariate-adjusted fracture incidence rates increased gradually after dialysis initiation and were 47% higher among women. Female sex, higher age, comorbidity, and previous history of MF (MF_previous) were associated with increased risk for MF_first, whereas peritoneal dialysis as compared to hemodialysis was associated with decreased risk. The adjusted fracture incidence rate of MF_first during the first 90 days following dialysis initiation was higher in patients with MF_previous than in those without MF_previous. MF_first independently predicted increased all-cause (sub-distribution hazard ratio, SHR, 1.67(95%CI 1.47-1.91)) and CVD (SHR 1.49 (95%CI 1.22-1.84)) mortality. Adjusted mortality rate following hip fractures was higher than for other types of MF. Spline curves showed that mortality following MF_first was highest during the first 6 months of follow-up.

CONCLUSIONS

MF are common and associated with increased mortality in incident dialysis patients.

Recombinant human soluble thrombomodulin attenuates anti-glomerular basement membrane glomerulonephritis in Wistar-Kyoto rats through anti-inflammatory effects

BACKGROUND

Since recombinant human soluble thrombomodulin (RH-TM) has anti-inflammatory properties through neutralizing high-mobility group box 1 protein (HMGB1), the protective effects of RH-TM were examined in anti-glomerular basement membrane (GBM) glomerulonephritis (GN) in Wistar-Kyoto rats.

METHODS

Rats were injected with nephrotoxic serum (NTS) to induce anti-GBM GN on Day 0, and were given either RH-TM or vehicle from Day 0 to Day 6. Rats were sacrificed 7 days after NTS injection.

RESULTS

RH-TM-treated rats had decreased proteinuria and serum creatinine level. RH-TM significantly reduced the percentage of glomeruli with crescentic features and fibrinoid necrosis. In addition, RH-TM-treated rats had significantly reduced glomerular ED1+ macrophage accumulation as well as reduced renal cortical proinflammatory cytokine expression. Furthermore, RH-TM had a potent effect in reducing intercellular adhesion molecule-1 (ICAM-1) expression in kidneys and urine. RH-TM significantly reduced renal cortical mRNA levels for toll-like receptor -2 and -4, known as receptors for HMGB1, and their downstream adopter protein, myeloid differentiation primary respond protein 88 (MyD88).

CONCLUSIONS

We showed for the first time that anti-inflammatory effects, which were characterized by reduced glomerular macrophage influx concomitant with a marked reduction in proinflammatory cytokines, were involved in the mechanism of attenuating experimental anti-GBM GN by RH-TM. The observed effects might be attributable to the downregulation of ICAM-1 by reducing the HMGB1/TLR/MyD88 signaling pathway.

Therapeutic Potential of Thrombomodulin in Renal Fibrosis of Nephrotoxic Serum Nephritis in Wistar-Kyoto Rats

BACKGROUND

Recombinant human soluble thrombomodulin (rhTM) was approved in 2008 and has been used for treatment of disseminated intravascular coagulation in Japan. The antifibrotic effects of rhTM in acute exacerbation of idiopathic pulmonary fibrosis are well established, but the therapeutic potential of rhTM in renal fibrosis remains poorly understood.

METHODS

Nephrotoxic serum nephritis (NTS-N) was induced in 22 female Wistar-Kyoto (WKY) rats on day 0. Rats were administered either rhTM or vehicle intraperitoneally, every day from day 4 to day 55. Rats were sacrificed on day 56 when renal fibrosis was established and renal morphological investigations were performed. In vitro, rat renal fibroblasts (NRK-49F) were pretreated with rhTM or saline, and expression levels of profibrogenic gene induced by thrombin were analyzed by real-time reverse transcription polymerase chain reaction.

RESULTS

Compared to WKY-GN-vehicle rats, the body weights of WKY-GN-rhTM rats were significantly greater on day 55. By day 56, rhTM had significantly reduced serum creatinine levels in NTS-N. On the other hand, urinary protein excretion was comparable between the two treatment groups throughout the study. The percentage of Masson trichrome-positive areas in WKY-GN-rhTM rats was significantly lower compared to that in WKY-GN-vehicle rats. Glomerular fibrin deposition was significantly reduced in WKY-GN-rhTM rats. In addition, rhTM significantly reduced the renal cortical mRNA expression levels of TNF-α, Toll-like receptor 4, MYD88, TGF-β, αSMA, collagen I, collagen III, fibronectin, and protease-activated receptor 1 (PAR1), a thrombin receptor. In vitro, thrombin stimulation of NRK-49F cells significantly enhanced the mRNA expression levels of αSMA and PAR1, and these upregulations were significantly reduced by pretreatment with rhTM.

CONCLUSIONS

Administration of rhTM after establishment of crescentic glomerulonephritis (GN) attenuated the subsequent development of renal fibrosis in NTS-N, possibly in part by inhibiting thrombin-mediated fibrogenesis. Our results suggest that rhTM may offer a therapeutic option for limiting the progression of chronic kidney disease in crescentic GN.

Bone mineral density at different sites and 5 years mortality in end-stage renal disease patients: A cohort study

BACKGROUND

Bone disease with osteoporosis and renal osteodystrophy is common in end stage renal disease (ESRD) patients and associates with cardiovascular disease (CVD) and increased morbimortality. We investigated associations of low bone mineral density (BMD) at various bone sites with five year all-cause and CVD mortality in ESRD patients.

METHODS

In a post hoc analysis of 426 ESRD patients (median age 56 years, 62% men) starting dialysis, BMD (whole-body dual-energy X-ray absorptiometry, DXA), body composition, nutritional status (subjective global assessment, SGA), handgrip strength (%HGS), Framingham CVD risk score (FRS) and biochemical biomarkers of nutrition and inflammation were assessed. We used the Fine and Gray competing risk regression analysis to assess survival analysis.

RESULTS

In multivariate logistic regression analysis, %HGS and intact parathyroid hormone associated with low tertile of: BMD_total, BMD_head and BMD_pelvis, after adjusting for FRS, SGA, %HGS, s-albumin, hsCRP, lean body mass index and year of recruitment. Patients with high FRS had low BMD_head (p<0.001). Low tertile of BMD_total (sHR, 1.53), BMD_head (sHR 1.54) and BMD_pelvis (sHR 1.60) associated with increased all-cause mortality whereas no such associations were found for the trabecular bone rich sites BMD arm, leg, trunk, rib or spine. Low tertile of BMD_total (sHR 1.94), BMD_head (sHR 1.68), BMD_leg (sHR 2.25) and BMD_pelvis (sHR 2.45) associated with increased CVD mortality whereas BMD at other sites did not associate with CVD mortality.

CONCLUSION

Low head and pelvis BMD, and low total BMD, as assessed by whole-body DXA, were independent predictors of increased risk of all-cause and CVD mortality. Cortical BMD appeared to have stronger association to survival in ESRD than trabecular BMD.

Serum uromodulin is associated with the severity of clinicopathological findings in ANCA-associated glomerulonephritis

Background

Uromodulin (UMOD), also known as Tamm-Horsfall protein, is a kidney-specific protein expressed by epithelial cells lining the thick ascending limb of the loop of Henle. In the current study, we aimed to clarify the clinical significance of UMOD in ANCA-associated glomerulonephritis (AAG).

Materials and methods

Sixty-one biopsy-proven AAG patients were included in this study. UMOD was measured using ELISA. The relationships between serum UMOD (sUMOD) levels and various clinicopathological findings were evaluated.

Results

AAG was classified into four categories (focal, crescentic, mixed, and sclerotic). In addition, tubulointerstitial lesions were classified as mild, moderate, and severe. The levels of sUMOD and urinary UMOD (uUMOD) were correlated with each other. A negative correlation between sUMOD levels and serum Cr levels, and positive correlation between sUMOD levels and eGFR were found. Patients in the high sUMOD group were associated with low serum Cr levels, focal classification, and mild tubulointerstitial injury compared to the low sUMOD group. Comparing the characteristics among histopathological classes, patients in the focal class had the best renal function and the highest levels of uUMOD/Cr and sUMOD. The focal class had significantly better renal survival compared with the severe histopathological classes (crescentic, mixed, and sclerotic). In univariate logistic regression analyses, prognostic factors for severe histopathological classes were low uUMOD/Cr, high serum Cr, and low sUMOD. Multivariate analyses revealed that low sUMOD predicted severe histopathological classes independent of serum Cr. The mean levels of sUMOD were significantly different between the focal class and severe histopathological classes, with a sensitivity of 70.6% and specificity of 90.0% (cut-off 143 ng/ml, AUC 0.80) by ROC curves.

Conclusion

Low sUMOD levels were associated with severe clinicopathological findings and might be considered as a risk factor for end stage renal disease in AAG.

Erlotinib attenuates the progression of chronic kidney disease in rats with remnant kidney

Background

Increasing evidence indicates that epidermal growth factor receptor (EGFR) has a pathogenic role in renal fibrosis. Currently no effective treatment can completely halt the progression of chronic kidney disease (CKD). This study was undertaken to investigate the renoprotective effects of erlotinib, a tyrosine kinase inhibitor that can block EGFR activity in the progression of CKD and the mechanisms involved.

Methods

Sprague Dawley rats with 5/6 nephrectomy were administered either erlotinib or vehicle from 2 weeks after surgery and for a period of 8 weeks. Blood pressure, proteinuria and serum creatinine were measured periodically. Renal morphological investigations were performed at sacrifice. In vitro, we used normal human mesangial cells (NHMCs) and human proximal tubular cells to investigate the inhibitory effects of erlotinib on renal fibrosis-associated signaling pathways by western blotting.

Results

Erlotinib treatment significantly blunted the progression of CKD as evidenced by reduced levels of serum creatinine, proteinuria and renal cortical profibrogenic genes and scores of glomerulosclerosis and tubulointerstitial damage. Tubulointerstitial macrophage infiltration and multiple pro-inflammatory cytokine gene expression levels were also attenuated by erlotinib treatment. In vitro, heparin-binding epidermal growth factor-like growth factor-induced Akt and extracellular-regulated kinase (ERK) 1/2 activation in normal human mesangial cells and human proximal tubular cells was inhibited by pretreatment with erlotinib.

Conclusions

EGFR blocking by erlotinib protected against renal fibrosis in 5/6 nephrectomized rats via inhibition of Akt and ERK 1/2 signaling pathways, which are associated with renal fibrosis. Erlotinib also has anti-inflammatory properties, which may contribute to its renoprotective effects. Erlotinib represents a potential novel therapeutic strategy for the treatment of CKD.

Elimination of intravenous alendronate by hemodialysis: A kinetic study

INTRODUCTION

The potential utility of intravenous alendronate for the treatment of osteoporosis in hemodialysis patients was recently reported. However, the pharmacokinetics of intravenous alendronate in patients on hemodialysis is not clear.

METHODS

Six hemodialysis patients (mean age, 80.5 years) with osteoporosis who had received intravenous alendronate prior to the study were enrolled. The participants received a 30-min infusion of 900-μg alendronate intravenously at the beginning of the dialysis session. The blood flow rate (Qb) and dialysate flow rate (Qd) were set at 200 mL/min and 500 mL/min, respectively. All patients used the same dialyzer (1.5-m² polysulfone membrane). At the completion of administration, plasma and dialysate samples were collected, and alendronate concentrations were determined using metal-free high-performance liquid chromatography (HPLC)-tandem mass spectrometry (MS/MS).

RESULTS

The plasma arterial alendronate concentration was 150.9 ± 46.09 ng/mL. It decreased through the dialyzer to 76.1 ± 34.1 ng/mL (venous alendronate concentration). Mean alendronate clearance was 113.9 ± 25.6 mL/min. Mean alendronate removal by hemodialysis, measured by the difference in arterial-venous concentrations, was 51.8%.

CONCLUSIONS

Fifty percent of intravenous alendronate was removed by hemodialysis, which is nearly equal to elimination of alendronate in patients with normal renal function. The elimination by hemodialysis would decrease the risk of excessive accumulation in bone. UMIN 000027182.

Effects of Denosumab and Alendronate on Bone Health and Vascular Function in Hemodialysis Patients: A Randomized, Controlled Trial

Mineral and bone disorders including osteoporosis are common in dialysis patients and contribute to increased morbimortality. However, whether denosumab and alendronate are effective and safe treatments in hemodialysis patients is not known. Thus, we conducted a prospective, three-center study of 48 hemodialysis patients who were diagnosed as having osteoporosis and had not received anti-osteoporotic agents previously. Participants were randomized to either denosumab or intravenous alendronate, and all subjects received elemental calcium and calcitriol during the initial 2 weeks. The primary endpoint was the percent change in lumbar spine bone mineral density (LSBMD) at 12 months of treatment. The secondary endpoints included the following: change in BMD at other sites; change of serum bone turnover markers (BTM), coronary artery calcium score (CACS), ankle-brachial pressure index (ABI), brachial-ankle pulse wave velocity (baPWV), flow mediated dilation (FMD), and intima-media thickness at the carotid artery (CA-IMT); change from day 0 to day 14 in serum levels of Ca and P; time course of serum calcium (Ca), phosphorus (P), and intact parathyroid hormone (i-PTH); new fractures; and adverse events. Initial supplementation with elemental calcium and calcitriol markedly ameliorated the decrease of serum corrected calcium (cCa) levels induced by denosumab during the first 2 weeks, whereas serum cCa levels in the alendronate group were increased. Denosumab and alendronate markedly decreased serum levels of BTM and increased LSBMD at 12 months compared with baseline. However, no significant differences were found in the changes in LSBMD between the two groups. The serum cCa, P, and i-PTH levels in the two groups were maintained within the appropriate range. In contrast to the anti-osteoporotic effects, no significant differences after 12 months of treatment were found in the CACS, CA-IMT, ABI, baPWV, and FMD compared with pretreatment in both groups. Denosumab and alendronate treatment improved LSBMD, reduced BTM, and appeared to be safe in hemodialysis patients with osteoporosis. © 2019 American Society for Bone and Mineral Research.

Clinical significance of serum and mesangial galactose-deficient IgA1 in patients with IgA nephropathy

Introduction

Galactose-deficient IgA1 (Gd-IgA1) is a critical pathogenic factor for IgA nephropathy (IgAN), but its value as a disease-specific biomarker remains controversial. We aimed to clarify the clinical significance of Gd-IgA1 in patients with IgAN.

Methods

We retrospectively reviewed 111 patients who were diagnosed with IgAN based on the findings of renal biopsies (RB) at Showa University Hospital since 2007. Serum Gd-IgA1 (s-Gd-IgA1) at the time of RB was compared among 111 IgAN patients, 18 Henoch-Schönlein purpura nephritis (HSPN) patients, 29 lupus nephritis (LN) patients, 28 ANCA-associated vasculitis (AAV) patients, and 13 minimal change disease (MCD) patients using ELISA with an anti-human Gd-IgA1-specific monoclonal antibody (KM55). We also immunohistochemically stained paraffin-embedded sections for mesangial Gd-IgA1 (m-Gd-IgA1) deposition using KM55.

Results

Although levels of s-Gd-IgA1 were comparable among IgAN and HSPN, s-Gd-IgA1 levels were significantly elevated in patients with IgAN compared with LN, AAV and MCD (IgAN vs. HSPN, LN, AAV, and MCD: 16.2 ± 9.1 vs. 14.2 ± 10.8, p = 0.263; 12.7 ± 9.4, p = 0.008; 13.1 ± 7.3, p = 0.059; and 8.2 ± 4.8 μg/mL, p<0.001, respectively). Mesangial-Gd-IgA1 deposition was specifically detected in IgAN or HSPN. The increase in s-Gd-IgA1 significantly correlated with m-Gd-IgA1 positivity in patients with IgAN, and s-Gd-IgA1 elevation and m-Gd-IgA1 deposition were evident in patients with histopathologically advanced IgAN. Moreover, s-Gd-IgA1 levels were significantly higher in IgAN patients with glomerular sclerosis and tubulo-interstitial lesions. Mesangial-Gd-IgA1 intensity negatively correlated with eGFR in IgAN. Multivariate analysis selected s-Gd-IgA1 elevation as a significant risk factor for a 30%-reduction in eGFR in IgAN (HR, 1.37; 95% CI, 1.02–1.89; p = 0.038).

Conclusions

Although IgAN and HSPN remain difficult to differentiate, s-Gd-IgA1 elevation and m-Gd-IgA1 deposition are reliable diagnostic factors that reflect IgAN severity. Serum-Gd-IgA1 could serve as a predictor of renal outcomes in IgAN. Thus, Gd-IgA1 could be significant biomarker for patients with IgAN.

The effects of denosumab and alendronate on glucocorticoid-induced osteoporosis in patients with glomerular disease: A randomized, controlled trial

INTRODUCTION

The clinical utility of denosumab for the treatment of glucocorticoid-induced osteoporosis (GIOP) has yet to be established. This study aimed to compare the effects of denosumab on bone mineral density (BMD) and bone turnover markers to those of alendronate in patients with GIOP.

METHODS

A prospective, single-center study of 32 patients (18 men; median age, 66.0 years) with glomerular disease receiving prednisolone (PSL) who were diagnosed as having GIOP and had not received bisphosphonates before was conducted. Participants were randomized to either alendronate (35 mg orally once a week) or denosumab (60 mg subcutaneously once every 6 months), and all subjects received calcitriol. The primary endpoint was the percent change in lumbar spine (LS) BMD at 12 months of treatment.

RESULTS

The demographic and clinical characteristics at baseline were not significantly different between the groups. Denosumab treatment markedly decreased serum levels of t-PINP, BAP, and TRACP-5b at 12 months compared to baseline (-57.4%, p<0.001; -30.9%, p<0.01; -57.7%, p<0.001, respectively). After 12 months of alendronate treatment, serum levels of t-PINP, BAP, and TRACP-5b were also significantly decreased compared to pretreatment (-38.9%, p<0.01; -16.3%, p<0.05; -43.5%, p<0.01, respectively). However, no significant differences in the changes of bone turnover markers were found between the two groups. As for the effects on BMD, denosumab treatment markedly increased LS BMD from 6 months compared to baseline, whereas no significant difference compared to pretreatment was found in the alendronate group during the study period. In the comparison of the two groups, a large increase of LS BMD was found in the denosumab treatment group compared to the alendronate treatment group at 12 months (p<0.05).

CONCLUSIONS

In patients with GIOP, denosumab treatment markedly suppressed bone turnover, which led to a significantly greater increase in LS BMD than with alendronate treatment. These results suggest that denosumab is a therapeutic option for the treatment of GIOP.

Rituximab for the treatment of type B insulin resistance syndrome: a case report and review of the literature

BACKGROUND

Type B insulin resistance syndrome is a rare disease characterized by refractory transient hyperglycaemia and severe insulin resistance associated with circulating anti-insulin receptor antibodies. A standardized treatment regimen for type B insulin resistance syndrome has yet to be established.

CASE REPORT

We report the case of a 64-year-old man undergoing haemodialysis for antineutrophil cytoplasmic antibody-associated vasculitis and diabetic nephropathy, who developed rapid onset of hyperglycaemia (glycated albumin 52.1%). Type B insulin resistance syndrome was diagnosed, on the basis of positivity for anti-insulin receptor antibodies and the man's autoimmune history of antineutrophil cytoplasmic antibody-associated vasculitis and idiopathic thrombocytopenic purpura. Although severe hyperglycaemia persisted in spite of corticosteroids and high-dose insulin therapy, rituximab treatment resulted in remarkable improvement of the man's severe insulin resistance and disappearance of anti-insulin receptor antibodies without any adverse effects.

CONCLUSIONS

According to a literature review of 11 cases in addition to the present case, rituximab appears to be a safe and effective strategy for the treatment of corticosteroid-resistant type B insulin resistance syndrome.

Combination Therapy of Denosumab and Calcitriol for a Renal Transplant Recipient with Severe Bone Loss due to Therapy-Resistant Hyperparathyroidism

Denosumab (DMAb), a complete human type monoclonal antibody directed against the receptor activator of nuclear factor-κB ligand, has gained attention as a novel treatment for osteoporosis. However, its efficacy in patients with chronic kidney disease (CKD) remains unclear. We describe a 64-year-old man with severe bone loss and persistent secondary hyperparathyroidism (SHPT) after renal transplantation, whose condition failed to respond to conventional pharmacologic or surgical interventions. He underwent parathyroidectomy with left forearm autograft of crushed tiny parathyroid gland (PTG) particles. However, the autografted PTGs became swollen and caused persistent SHPT in spite of two additional parathyroidectomies of the left forearm. A single subcutaneous administration of DMAb induced hypocalcemia, which was corrected by calcium supplementation and high-dose calcitriol. Eventually, combination therapy with DMAb and calcitriol led to a decline in the patient's elevated serum parathyroid hormone levels, normalization of laboratory markers of bone metabolism, and improvement in bone mineral density in a short period of time. To the best of our knowledge, this is the first case report of severe bone loss with persistent SHPT in a renal transplant recipient effectively treated with the combination therapy of DMAb and vitamin D (VD). Although DMAb itself exerts no direct effects on PTGs, the DMAb treatment improved the patient's bone loss. In addition, administration of DMAb allowed for high-dose VD therapy which ultimately controlled SHPT and prevented DMAb-induced hypocalcemia. Therefore, this combination therapy might be a reasonable therapeutic strategy to reverse severe bone loss due to therapy-resistant SHPT in patients with CKD.

Anti-Phospholipase A2 Receptor (PLA2R) Antibody and Glomerular PLA2R Expression in Japanese Patients with Membranous Nephropathy

The phospholipase A2 receptor (PLA2R) is the major target antigen (Ag) in idiopathic membranous nephropathy (IMN). Recently, several types of immunoassay systems for anti-PLA2R antibody (Ab) have been developed. However, the correlation of serum anti-PLA2R Abs and glomerular expression of PLA2R Ag, and their association with clinicopathological characteristics have yet to be proven in Japanese patients. We examined serum anti-PLA2R Abs by both ELISA and cell-based indirect immunofluorescence assay (CIIFA), and glomerular PLA2R expression by immunofluorescence (IF) in 59 biopsy-proven MN patients including IMN (n = 38) and secondary MN (SMN) (n = 21). In this study, anti-PLA2R Abs were present in 50% of IMN patients, but was absent in SMN patients. The concordance rate between ELISA and CIIFA was 100%. Serum IgG levels were significantly lower in anti-PLA2R Ab-positive patients. Serum albumin levels correlated inversely with serum anti-PLA2R Ab titers. The prevalence and intensity of glomerular staining for IgG4 by IF were significantly higher in anti-PLA2R Ab-positive patients than in -negative patients. Glomerular PLA2 Ag expression evaluated by IF was positive in 52.6% of IMN patients, but was absent in SMN patients. The concordance rate between the prevalence of glomerular PLA2R Ag expression and anti-PLA2R Ab was 84.2%. The prevalence of anti-PLA2R Abs measured by ELISA/CIIFA was equivalent to previous Japanese studies evaluated using Western blotting. These analyses showed an excellent specificity for the diagnosis of IMN, and anti-PLA2R positivity was associated with some clinicopathological features, especially glomerular IgG4-dominant deposition.

Therapeutic effects and mechanism of conditioned media from human mesenchymal stem cells on anti-GBM glomerulonephritis in WKY rats

Recent studies have demonstrated that conditioned media derived from mesenchymal stem cells (MSC-CM) have therapeutic effects in various experimental diseases. However, the therapeutic mechanism is not fully understood. In the present study, we investigated the therapeutic effects and mechanism of MSC-CM in experimental antiglomerular basement membrane glomerulonephritis. We administered either MSC-CM or vehicle from day 0 to day 10 after the induction of nephrotoxic serum nephritis in Wistar-Kyoto rats. In vitro, we analyzed the effects of MSC-CM on TNF-α-mediated cytokine production in cultured normal human mesangial cells, proximal tubular (HK-2) cells, human umbilical vein endothelial cells, and monocytes (THP-1 and peripheral blood mononuclear cells). Compared with vehicle treatment, MSC-CM treatment improved proteinuria and renal dysfunction. Histologically, MSC-CM-treated rats had reduced crescent formation and glomerular ED1+ macrophage infiltration and increased glomerular ED2+ macrophage infiltration. Increased serum monocyte chemoattractant protein (MCP)-1 levels were observed in MSC-CM-treated rats. Renal cortical mRNA expression levels of proinflammatory cytokines, such as TNF-α and IL-6, and of the T helper cell 1 cytokine interferon-γ were greatly decreased by MSC-CM treatment. In vitro, pretreatment with MSC-CM blocked TNF-α-mediated IL-8 release in normal human mesangial cells and HK-2 cells. TNF-α-mediated MCP-1 release was enhanced by pretreatment with MSC-CM in human umbilical vein endothelial cells and HK-2 cells and was strikingly enhanced in THP-1 cells. Stimulation of peripheral blood mononuclear cells with a combination of MCP-1 and IL-4 enhanced the expression of M2-associated genes compared with IL-4 alone. We demonstrated that MSC-CM had therapeutic effects in experimental antiglomerular basement membrane glomerulonephritis that were mediated through anti-inflammatory effects that were partly due to acceleration of M2 macrophage polarization, which might be mediated by MCP-1 enhancement.

Streptococcal Infection-related Nephritis (SIRN) Manifesting Membranoproliferative Glomerulonephritis Type I

We herein report the case of an 18-year-old boy who developed nephrotic syndrome and hypertension after upper airway inflammation. Post-streptococcal acute glomerulonephritis was diagnosed on the basis of a high antistreptolysin O titer, hypocomplementemia, proteinuria, and microscopic hematuria. A renal biopsy was performed due to persistent proteinuria, and the pathological diagnosis was membranoproliferative glomerulonephritis (MPGN) type I. Glomeruli showed positive staining for nephritis-associated plasmin receptor (NAPlr), a nephritogenic group A streptococcal antigen, and plasmin activity was found in a similar distribution as NAPlr deposition. This rare case of streptococcal infection-related nephritis (SIRN) manifesting MPGN type I supports the histological diversity of SIRN.