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Rationale & objectivePlasma kidney injury molecule 1 (KIM-1) is a sensitive marker of proximal tubule injury, but its association with risks of adverse clinical outcomes across a spectrum of kidney diseases is unknown.Study designProspective, observational cohort study.Setting & participants524 individuals enrolled into the Boston Kidney Biopsy Cohort (BKBC) Study undergoing clinically indicated native kidney biopsy with biopsy specimens adjudicated for semiquantitative scores of histopathology by 2 kidney pathologists and 3,800 individuals with common forms of chronic kidney disease (CKD) enrolled into the Chronic Renal Insufficiency Cohort (CRIC) Study.ExposureHistopathologic lesions and clinicopathologic diagnosis in cross-sectional analyses, baseline plasma KIM-1 levels in prospective analyses.OutcomesBaseline plasma KIM-1 levels in cross-sectional analyses, kidney failure (defined as initiation of kidney replacement therapy) and death in prospective analyses.Analytical approachMultivariable-adjusted linear regression models tested associations of plasma KIM-1 levels with histopathologic lesions and clinicopathologic diagnoses. Cox proportional hazards models tested associations of plasma KIM-1 levels with future kidney failure and death.ResultsIn the BKBC Study, higher plasma KIM-1 levels were associated with more severe acute tubular injury, tubulointerstitial inflammation, and more severe mesangial expansion after multivariable adjustment. Participants with diabetic nephropathy, glomerulopathies, and tubulointerstitial disease had significantly higher plasma KIM-1 levels after multivariable adjustment. In the BKBC Study, CKD in 124 participants progressed to kidney failure and 85 participants died during a median follow-up time of 5 years. In the CRIC Study, CKD in 1,153 participants progressed to kidney failure and 1,356 participants died during a median follow-up time of 11.5 years. In both cohorts, each doubling of plasma KIM-1 level was associated with an increased risk of kidney failure after multivariable adjustment (hazard ratios of 1.19 [95% CI, 1.03-1.38] and 1.10 [95% CI, 1.06-1.15] for BKBC and CRIC, respectively). There was no statistically significant association of plasma KIM-1 levels with death in either cohort.LimitationsGeneralizability and unmeasured confounding.ConclusionsPlasma KIM-1 is associated with underlying tubulointerstitial and mesangial lesions and progression to kidney failure in 2 cohort studies of individuals with kidney diseases.

ImportanceOxalate is a potentially toxic terminal metabolite that is eliminated primarily by the kidneys. Oxalate nephropathy is a well-known complication of rare genetic disorders and enteric hyperoxaluria, but oxalate has not been investigated as a potential contributor to more common forms of chronic kidney disease (CKD).ObjectiveTo assess whether urinary oxalate excretion is a risk factor for more rapid progression of CKD toward kidney failure.Design, setting, and participantsThis prospective cohort study assessed 3123 participants with stages 2 to 4 CKD who enrolled in the Chronic Renal Insufficiency Cohort study from June 1, 2003, to September 30, 2008. Data analysis was performed from October 24, 2017, to June 17, 2018.ExposuresTwenty-four-hour urinary oxalate excretion.Main outcomes and measuresA 50% decline in estimated glomerular filtration rate (eGFR) and end-stage renal disease (ESRD).ResultsThis study included 3123 participants (mean [SD] age, 59.1 [10.6] years; 1414 [45.3%] female; 1423 [45.6%] white). Mean (SD) eGFR at the time of 24-hour urine collection was 42.9 (16.8) mL/min/1.73 m2. Median urinary excretion of oxalate was 18.6 mg/24 hours (interquartile range [IQR], 12.9-25.7 mg/24 hours) and was correlated inversely with eGFR (r = -0.13, P

Rationale & objectiveUric acid is excreted by the kidney and accumulates in acute kidney injury (AKI). Whether higher plasma uric acid level predisposes to AKI or its complications is not known.Study designProspective observational cohort study.Setting & participants2 independent cohorts of critically ill patients: (1) 208 patients without AKI admitted to the intensive care unit (ICU) at Brigham & Women's Hospital between October 2008 and December 2016; and (2) 250 participants with AKI requiring renal replacement therapy (RRT) who had not yet initiated RRT enrolled in the Acute Renal Failure Trial Network (ATN) Study.ExposurePlasma uric acid level upon ICU admission and before RRT initiation in the ICU and ATN Study cohorts, respectively.OutcomesIncident AKI and 60-day mortality in the ICU and ATN Study cohorts, respectively.Analytical approachLogistic regression models were used to test the association of plasma uric acid level with incident AKI and 60-day mortality.ResultsIn the ICU cohort, median plasma uric acid level was 4.7 (interquartile range [IQR], 3.6-6.4) mg/dL, and 40 patients (19.2%) developed AKI. Higher plasma uric acid levels associated with incident AKI, but this association was confounded by serum creatinine level and was not significant after multivariable adjustment (adjusted OR per doubling of uric acid, 1.50; 95% CI, 0.80-2.81). In the ATN Study cohort, median plasma uric acid level was 11.1 (IQR, 8.6-14.2) mg/dL, and 125 participants (50.0%) died within 60 days. There was no statistically significant association between plasma uric acid levels and 60-day mortality in either unadjusted models or after multivariable adjustment for demographic, severity-of-illness, and kidney-specific covariates (adjusted OR per doubling of uric acid, 1.15; 95% CI, 0.71-1.86).LimitationsHeterogeneity of ICU patients.ConclusionsPlasma uric acid levels upon ICU admission or before RRT initiation are not independently associated with adverse clinical outcomes in critically ill patients.

Albuminuria above the normal range is a major risk factor for disease progression among those with chronic kidney disease (CKD). This study examines the prognostic value of albuminuria within the normoalbuminuric range in persons with CKD. Visual Abstract. Association of Albuminuria With Chronic Kidney Disease Progression in Persons With Chronic Kidney Disease and Normoalbuminuria: Albuminuria above the normal range is a major risk factor for disease progression among those with chronic kidney disease (CKD). This study examines the prognostic value of albuminuria within the normoalbuminuric range in persons with CKD. Background: Albuminuria is a major risk factor for chronic kidney disease (CKD) progression, especially when categorized as moderate (30 to 300 mg/g) or severe (>300 mg/g). However, there are limited data on the prognostic value of albuminuria within the normoalbuminuric range (<30 mg/g) in persons with CKD. Objective: To estimate the increase in the cumulative incidence of CKD progression with greater baseline levels of albuminuria among persons with CKD who had normoalbuminuria (<30 mg/g). Design: Multicenter prospective cohort study. Setting: 7 U.S. clinical centers. Participants: 1629 participants meeting criteria from the CRIC (Chronic Renal Insufficiency Cohort) study with CKD (estimated glomerular filtration rate [eGFR], 20 to 70 mL/min/1.73 m 2) and urine albumin–creatinine ratio (UACR) less than 30 mg/g. Measurements: Baseline spot urine albumin divided by spot urine creatinine to calculate UACR as the exposure variable. The 10-year adjusted cumulative incidences of CKD progression (composite of 50% eGFR decline or kidney failure [dialysis or kidney transplantation]) from confounder adjusted survival curves using the G-formula. Results: Over a median follow-up of 9.8 years, 182 of 1629 participants experienced CKD progression. The 10-year adjusted cumulative incidences of CKD progression were 8.7% (95% CI, 5.9% to 11.6%), 11.5% (CI, 8.8% to 14.3%), and 19.5% (CI, 15.4% to 23.5%) for UACR levels of 0 to less than 5 mg/g, 5 to less than 15 mg/g, and 15 mg/g or more, respectively. Comparing persons with UACR 15 mg/g or more to those with UACR 5 to less than 15 mg/g and 0 to less than 5 mg/g, the absolute risk differences were 7.9% (CI, 3.0% to 12.7%) and 10.7% (CI, 5.8% to 15.6%), respectively. The 10-year adjusted cumulative incidence increased linearly based on baseline UACR levels. Limitation: UACR was measured once. Conclusion: Persons with CKD and normoalbuminuria (<30 mg/g) had excess risk for CKD progression, which increased in a linear fashion with higher levels of albuminuria. Primary Funding Source: None. [ABSTRACT FROM AUTHOR]

Background Protein biomarkers may provide insight into kidney disease pathology but their use for the identification of phenotypically distinct kidney diseases has not been evaluated. Methods We used unsupervised hierarchical clustering on 225 plasma biomarkers in 541 individuals enrolled into the Boston Kidney Biopsy Cohort, a prospective cohort study of individuals undergoing kidney biopsy with adjudicated histopathology. Using principal component analysis, we studied biomarker levels by cluster and examined differences in clinicopathologic diagnoses and histopathologic lesions across clusters. Cox proportional hazards models tested associations of clusters with kidney failure and death. Results We identified three biomarker-derived clusters. The mean estimated glomerular filtration rate was 72.9 ± 28.7, 72.9 ± 33.4 and 39.9 ± 30.4 mL/min/1.73 m2 in Clusters 1, 2 and 3, respectively. The top-contributing biomarker in Cluster 1 was AXIN, a negative regulator of the Wnt signaling pathway. The top-contributing biomarker in Clusters 2 and 3 was Placental Growth Factor, a member of the vascular endothelial growth factor family. Compared with Cluster 1, individuals in Cluster 3 were more likely to have tubulointerstitial disease (P  < .001) and diabetic kidney disease (P  < .001) and had more severe mesangial expansion [odds ratio (OR) 2.44, 95% confidence interval (CI) 1.29, 4.64] and inflammation in the fibrosed interstitium (OR 2.49 95% CI 1.02, 6.10). After multivariable adjustment, Cluster 3 was associated with higher risks of kidney failure (hazard ratio 3.29, 95% CI 1.37, 7.90) compared with Cluster 1. Conclusion Plasma biomarkers may identify clusters of individuals with kidney disease that associate with different clinicopathologic diagnoses, histopathologic lesions and adverse outcomes, and may uncover biomarker candidates and relevant pathways for further study. [ABSTRACT FROM AUTHOR]

Background Whether calcium oxalate (CaOx) deposition in kidney allografts following transplantation (Tx) adversely affects patient outcomes is uncertain, as are its associated risk factors. Methods We performed a retrospective cohort study of patients who had kidney allograft biopsies performed within 3 months of Tx at Brigham and Women's Hospital and examined the association of CaOx deposition with the composite outcome of death or graft failure within 5 years. Results Biopsies from 67 of 346 patients (19.4%) had CaOx deposition. In a multivariable logistic regression model, higher serum creatinine [odds ratio (OR) = 1.28 per mg/dL, 95% confidence interval (CI) 1.15–1.43], longer time on dialysis (OR = 1.11 per additional year, 95% CI 1.01–1.23) and diabetes (OR = 2.26, 95% CI 1.09–4.66) were found to be independently associated with CaOx deposition. CaOx deposition was strongly associated with delayed graft function (DGF; OR = 11.31, 95% CI 5.97–21.40), and with increased hazard of the composite outcome after adjusting for black recipient race, donor type, time on dialysis before Tx, diabetes and borderline or acute rejection (hazard ratio 1.90, 95% CI 1.13–3.20). Conclusions CaOx deposition is common in allografts with poor function and portends worse outcomes up to 5 years after Tx. The extent to which CaOx deposition may contribute to versus result from DGF, however, cannot be determined based on our retrospective and observational data. Future studies should examine whether reducing plasma and urine oxalate prevents CaOx deposition in the newly transplanted kidney and whether this has an effect on clinical outcomes. [ABSTRACT FROM AUTHOR]

Women with Bernard-Soulier syndrome (BSS) are considered to be at high risk of serious bleeding during childbirth. Due to the frequently occurring platelet transfusion refractoriness, alternative prophylactic therapy is required. Using rotational thromboelastometry, we evaluated the whole blood coagulation profile of a pregnant woman with BSS before and after spiking ex vivo with different concentrations of recombinant activated factor VII (rFVIIa) and fibrinogen. As experiments suggested improved clotting with clinically applicable concentrations of both agents in a complementary manner, the findings were confirmed on blood from a non-pregnant woman and three men suffering from BSS. During delivery, bleeding refractory to platelets occurred and immediately following delivery she received both rFVIIa and fibrinogen intravenously. Immediate cessation of bleeding occurred, and no postpartum hemorrhage was seen. Another woman with BSS later also received the same rFVIIa and fibrinogen treatment prophylactically after delivery without any postpartum bleeding. Eventually, the first woman during her second delivery received the same treatment again prophylactically without any bleeding. No side effects were observed during these three deliveries. Our observations suggest that rFVIIa combined with fibrinogen may provide a beneficial clinical hemostatic effect partly by separate but complementary mechanisms. [ABSTRACT FROM AUTHOR]

Curhan,GearoidM.McMahonandSushrutS.Waikar:RenalDivision,Brighamand Women'sHospital,Boston,MA,USA HelmutG. Copyright of Nephrology Dialysis Transplantation is the property of Oxford University Press / USA and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. Rennke:RenalPathologyService,BrighamandWomen'sHospital,Boston,MA,USA Intheresultssectionoftheabstract"1.28mg/dL"hasbeencorrectedto"1.28permg/dL". doi:10.1093/ndt/gfy364 AdvanceAccess publication 22Dec2018 IkutoMasakaneandKenjiSakurai Currentapproachestomiddlemoleculeremoval:roomforinnovation,NephrologyDialysisTransplantation,Volume33,Issue suppl 3,1October2018,Pagesiii12-iii21,https://doi.org/10.1093/ndt/gfy224 Intheintroductionofthisarticle(piii13)theMWinthesentence"A1Misa183aminoacidpeptidewithaMWof330000Da"has beencorrectedto33000. [Extracted from the article]