Development and validation of a race-agnostic computable phenotype for kidney health in adult hospitalized patients

Standard race adjustments for estimating glomerular filtration rate (GFR) and reference creatinine can yield a lower acute kidney injury (AKI) and chronic kidney disease (CKD) prevalence among African American patients than non-race adjusted estimates. We developed two race-agnostic computable phenotypes that assess kidney health among 139,152 subjects admitted to the University of Florida Health between 1/2012-8/2019 by removing the race modifier from the estimated GFR and estimated creatinine formula used by the race-adjusted algorithm (race-agnostic algorithm 1) and by utilizing 2021 CKD-EPI refit without race formula (race-agnostic algorithm 2) for calculations of the estimated GFR and estimated creatinine. We compared results using these algorithms to the race-adjusted algorithm in African American patients. Using clinical adjudication, we validated race-agnostic computable phenotypes developed for preadmission CKD and AKI presence on 300 cases. Race adjustment reclassified 2,113 (8%) to no CKD and 7,901 (29%) to a less severe CKD stage compared to race-agnostic algorithm 1 and reclassified 1,208 (5%) to no CKD and 4,606 (18%) to a less severe CKD stage compared to race-agnostic algorithm 2. Of 12,451 AKI encounters based on race-agnostic algorithm 1, race adjustment reclassified 591 to No AKI and 305 to a less severe AKI stage. Of 12,251 AKI encounters based on race-agnostic algorithm 2, race adjustment reclassified 382 to No AKI and 196 (1.6%) to a less severe AKI stage. The phenotyping algorithm based on refit without race formula performed well in identifying patients with CKD and AKI with a sensitivity of 100% (95% confidence interval [CI] 97%-100%) and 99% (95% CI 97%-100%) and a specificity of 88% (95% CI 82%-93%) and 98% (95% CI 93%-100%), respectively. Race-agnostic algorithms identified substantial proportions of additional patients with CKD and AKI compared to race-adjusted algorithm in African American patients. The phenotyping algorithm is promising in identifying patients with kidney disease and improving clinical decision-making.

Pea hull fiber supplementation does not modulate uremic metabolites in adults receiving hemodialysis: a randomized, double-blind, controlled trial

Background

Fiber is a potential therapeutic to suppress microbiota-generated uremic molecules. This study aimed to determine if fiber supplementation decreased serum levels of uremic molecules through the modulation of gut microbiota in adults undergoing hemodialysis.

Methods

A randomized, double-blinded, controlled crossover study was conducted. Following a 1-week baseline, participants consumed muffins with added pea hull fiber (PHF) (15 g/d) and control muffins daily, each for 4 weeks, separated by a 4-week washout. Blood and stool samples were collected per period. Serum p-cresyl sulfate (PCS), indoxyl sulfate (IS), phenylacetylglutamine (PAG), and trimethylamine N-oxide (TMAO) were quantified by LC-MS/MS, and fecal microbiota profiled by 16S rRNA gene amplicon sequencing and specific taxa of interest by qPCR. QIIME 2 sample-classifier was used to discover unique microbiota profiles due to the consumption of PHF.

Results

Intake of PHF contributed an additional 9 g/d of dietary fiber to the subjects' diet due to compliance. No significant changes from baseline were observed in serum PCS, IS, PAG, or TMAO, or for the relative quantification of Akkermansia muciniphila, Faecalibacterium prausnitzii, Bifidobacterium, or Roseburia, taxa considered health-enhancing. Dietary protein intake and IS (r = -0.5, p = 0.05) and slow transit stool form and PCS (r = 0.7, p < 0.01) were significantly correlated at baseline. PHF and control periods were not differentiated; however, using machine learning, taxa most distinguishing the microbiota composition during the PHF periods compared to usual diet alone were enriched Gemmiger, Collinsella, and depleted Lactobacillus, Ruminococcus, Coprococcus, and Mogibacteriaceae.

Conclusion

PHF supplementation did not mitigate serum levels of targeted microbial-generated uremic molecules. Given the high cellulose content, which may be resistant to fermentation, PHF may not exert sufficient effects on microbiota composition to modulate its activity at the dose consumed.

EARLY DIFFERENTIATION BETWEEN SEPSIS AND STERILE INFLAMMATION VIA URINARY GENE SIGNATURES OF METABOLIC DYSREGULATION

ABSTRACT

Objective: The aim of this study was to characterize early urinary gene expression differences between patients with sepsis and patients with sterile inflammation and summarize in terms of a reproducible sepsis probability score. Design: This was a prospective observational cohort study. Setting: The study was conducted in a quaternary care academic hospital. Patients: One hundred eighty-six sepsis patients and 78 systemic inflammatory response syndrome (SIRS) patients enrolled between January 2015 and February 2018. Interventions: Whole-genome transcriptomic analysis of RNA was extracted from urine obtained from sepsis patients within 12 hours of sepsis onset and from patients with surgery-acquired SIRS within 4 hours after major inpatient surgery. Measurements and Main Results: We identified 422 of 23,956 genes (1.7%) that were differentially expressed between sepsis and SIRS patients. Differentially expressed probes were provided to a collection of machine learning feature selection models to identify focused probe sets that differentiate between sepsis and SIRS. These probe sets were combined to find an optimal probe set (UrSepsisModel) and calculate a urinary sepsis score (UrSepsisScore), which is the geometric mean of downregulated genes subtracted from the geometric mean of upregulated genes. This approach summarizes the expression values of all decisive genes as a single sepsis score. The UrSepsisModel and UrSepsisScore achieved area under the receiver operating characteristic curves 0.91 (95% confidence interval, 0.86-0.96) and 0.80 (95% confidence interval, 0.70-0.88) on the validation cohort, respectively. Functional analyses of probes associated with sepsis demonstrated metabolic dysregulation manifest as reduced oxidative phosphorylation, decreased amino acid metabolism, and decreased oxidation of lipids and fatty acids. Conclusions: Whole-genome transcriptomic profiling of urinary cells revealed focused probe panels that can function as an early diagnostic tool for differentiating sepsis from sterile SIRS. Functional analysis of differentially expressed genes demonstrated a distinct metabolic dysregulation signature in sepsis.

Clinical Trajectories of Acute Kidney Injury in Surgical Sepsis: A Prospective Observational Study

OBJECTIVE

To characterize endothelial function, inflammation, and immunosuppression in surgical patients with distinct clinical trajectories of AKI and to determine the impact of persistent kidney injury and renal non-recovery on clinical outcomes, resource utilization, and long-term disability and survival.

SUMMARY OF BACKGROUND DATA

AKI is associated with increased healthcare costs and mortality. Trajectories that account for duration and recovery of AKI have not been described for sepsis patients, who are uniquely vulnerable to renal dysfunction.

METHODS

This prospective observational study included 239 sepsis patients admitted and enrolled between January 2015 and July 2017. Kidney Disease: Improving Global Outcomes (KDIGO) and Acute Disease Quality Initiative (ADQI) criteria were used to classify subjects as having no AKI, rapidly reversed AKI, persistent AKI with renal recovery, or persistent AKI without renal recovery. Serial biomarker profiles, clinical outcomes, resource utilization, and long-term physical performance status and survival were compared among AKI trajectories.

RESULTS

Sixty-two percent of the study population developed AKI. Only one-third of AKI episodes rapidly reversed within 48 hours; the remaining had persistent AKI, among which 57% did not have renal recovery by discharge. One-year survival and proportion of subjects fully active 1 year after sepsis was lowest among patients with persistent AKI compared with other groups. Long-term mortality hazard rates were 5-fold higher for persistent AKI without renal recovery compared with no AKI.

CONCLUSIONS

Among critically ill surgical sepsis patients, persistent AKI and the absence of renal recovery are associated with distinct early and sustained immunologic and endothelial biomarker signatures and decreased long-term physical function and survival.

Association of persistent acute kidney injury and renal recovery with mortality in hospitalised patients

Objectives

Acute kidney injury (AKI) affects up to one-quarter of hospitalised patients and 60% of patients in the intensive care unit (ICU). We aim to understand the baseline characteristics of patients who will develop distinct AKI trajectories, determine the impact of persistent AKI and renal non-recovery on clinical outcomes, resource use, and assess the relative importance of AKI severity, duration and recovery on survival.

Methods

In this retrospective, longitudinal cohort study, 156 699 patients admitted to a quaternary care hospital between January 2012 and August 2019 were staged and classified (no AKI, rapidly reversed AKI, persistent AKI with and without renal recovery). Clinical outcomes, resource use and short-term and long-term survival adjusting for AKI severity were compared among AKI trajectories in all cohort and subcohorts with and without ICU admission.

Results

Fifty-eight per cent (31 500/54 212) had AKI that rapidly reversed within 48 hours; among patients with persistent AKI, two-thirds (14 122/22 712) did not have renal recovery by discharge. One-year mortality was significantly higher among patients with persistent AKI (35%, 7856/22 712) than patients with rapidly reversed AKI (15%, 4714/31 500) and no AKI (7%, 22 117/301 466). Persistent AKI without renal recovery was associated with approximately fivefold increased hazard rates compared with no AKI in all cohort and ICU and non-ICU subcohorts, independent of AKI severity.

Discussion

Among hospitalised, ICU and non-ICU patients, persistent AKI and the absence of renal recovery are associated with reduced long-term survival, independent of AKI severity.

Conclusions

It is essential to identify patients at risk of developing persistent AKI and no renal recovery to guide treatment-related decisions.

LC-MS lipidomics of renal biopsies for the diagnosis of Fabry disease

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Fabry is an X-linked lysosomal storage disease with deficiency in α-galactosidase.

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This deficiency results in the accumulation of glycosphinogolipids.

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Diagnosis is often made by analysis of globotriaosylceramide in fluids and tissues.

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Fabry is often misdiagnosed in female patients due to residual enzyme activity.

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Lipidomics by LC-HRMS enables identification of new biomarkers in Fabry.

Introduction

Lipidomics analysis or lipid profiling is a system-based analysis of all lipids in a sample to provide a comprehensive understanding of lipids within a biological system. In the last few years, lipidomics has made it possible to better understand the metabolic processes associated with several rare disorders and proved to be a powerful tool for their clinical investigation. Fabry disease is a rare X-linked lysosomal storage disorder (LSD) caused by a deficiency in α-galactosidase A (α-GAL A). This deficiency results in the progressive accumulation of glycosphingolipids, mostly globotriaosylceramide (Gb₃), globotriaosylsphingosine (lyso-Gb₃), as well as galabiosylceramide (Ga₂) and their isoforms/analogs in the vascular endothelium, nerves, cardiomyocytes, renal glomerular podocytes, and biological fluids.

Objectives

The primary objective of this study was to evaluate lipidomic signatures in renal biopsies to help understand variations in Fabry disease markers that could be used in future diagnostic tests.

Methods

Lipidomic analysis was performed by ultra-high pressure liquid chromatography-high-resolution mass spectrometry (UHPLC-HRMS) on kidney biopsies that were left over after clinical pathology analysis to diagnose Fabry disease.

Results

We employed UHPLC-HRMS lipidomics analysis on the renal biopsy of a patient suspicious for Fabry disease. Our result confirmed α-GAL A enzyme activity declined in this patient since a Ga2-related lipid biomarker was substantially higher in the patient's renal tissue biopsy compared with two controls. This suggests this patient has a type of LSD that could be non-classical Fabry disease.

Conclusion

This study shows that lipidomics analysis is a valuable tool for rare disorder diagnosis, which can be conducted on leftover tissue samples without disrupting normal patient care.

Provision of Kidney Disease Education Service Is Associated with Improved Vascular Access Outcomes among US Incident Hemodialysis Patients

Background

Pre-ESKD Kidney Disease Education (KDE) has been shown to improve multiple CKD outcomes, but its effect on vascular access outcomes is not well studied. In 2010, Medicare launched KDE reimbursements policy for patients with advanced CKD.

Methods

In this retrospective USRDS analysis, we identified all adult patients on incident hemodialysis with ≥6 months of pre-ESKD Medicare coverage during the first 5 years of CMS-KDE policy and divided them into CMS-KDE services recipients (KDE cohort) and nonrecipients (non-KDE cohort). The primary outcome was incident arteriovenous fistula (AVF) and the composite of incident AVF or arteriovenous graft (AVG) utilization. Secondary outcomes were central venous catheter (CVC) with maturing AVF/AVG and pure CVC utilizations. Step-wise multivariate analyses were performed in four progressive models (model 1, KDE alone; model 2, multivariate model encompassing model 1 with sociodemographics; model 3, model 2 with comorbidity and functional status; and model 4, model 3 with pre-ESKD nephrology care).

Results

Of the 211,990 qualifying patients on incident hemodialysis during the study period, 2887 (1%) received KDE services before dialysis initiation. The rates of incident AVF and composite AVF/AVG were more than double (30% and 35%, respectively, compared with 14% and 17%), and pure catheter use about a third lower (40% compared with 65%) in the KDE cohort compared with the non-KDE cohort. The maximally adjusted odds ratios in model 4 for study outcomes were incident AVF use, 1.78, 99% confidence interval, 1.55 to 2.05; incident AVF/AVG use, 1.78, 99% confidence interval, 1.56 to 2.03; incident CVC with maturing AVF/AVG, 1.69, 99% confidence interval, 1.44 to 1.97; and pure CVC without any AVF/AVG, 0.51, 99% confidence interval, 0.45 to 0.58. The benefits of the KDE service were maintained even after accounting for the presence, duration, and facility of ESKD care.

Conclusion

The occurrence of pre-ESRD KDE service is associated with significantly improved incident vascular access outcomes. Targeted studies are needed to examine the effect of KDE on patient engagement and self-efficacy as a cause for improvement in vascular access outcomes.

Utilization of CMS pre-ESRD Kidney Disease Education services and its associations with the home dialysis therapies

BACKGROUND

Kidney Disease Education (KDE) has been shown to improve informed dialysis selection and home dialysis use, two long-held but underachieved goals of US nephrology community. In 2010, the Center for Medicare and Medicaid Services launched a policy of KDE reimbursements for all Medicare beneficiaries with advanced chronic kidney disease. However, the incorporation of KDE service in real-world practice and its association with the home dialysis utilization has not been examined.

METHODS

Using the 2016 US Renal Data System linked to end-stage renal disease (ESRD) and pre-ESRD Medicare claim data, we identified all adult incident ESRD patients with active Medicare benefits at their first-ever dialysis during the study period (1 January 2010 to 31 December 2014). From these, we identified those who had at least one KDE service code before their dialysis initiation (KDE cohort) and compared them to a parsimoniously matched non-KDE control cohort in 1:4 proportions for age, gender, ESRD network, and the year of dialysis initiation. The primary outcome was home dialysis use at dialysis initiation, and secondary outcomes were home dialysis use at day 90 and anytime through the course of ESRD.

RESULTS

Of the 369,968 qualifying incident ESRD Medicare beneficiaries with their first-ever dialysis during the study period, 3469 (0.9%) received KDE services before dialysis initiation. African American race, Hispanic ethnicity, and the presence of congestive heart failure and hypoalbuminemia were associated with significantly lower odds of receiving KDE services. Multivariate analyses showed that KDE recipients had twice the odds of initiating dialysis with home modalities (15.0% vs. 6.9%; adjusted odds ratio (aOR):95% confidence interval (CI) 2.0:1.7-2.4) and had significantly higher odds using home dialysis throughout the course of ESRD (home dialysis use at day 90 (17.6% vs. 9.9%, aOR:CI 1.7:1.4-1.9) and cumulatively (24.7% vs. 15.1%, aOR:CI 1.7:1.5-1.9)).

CONCLUSIONS

Utilization of pre-ESRD KDE services is associated with significantly greater home dialysis utilization in the incident ESRD Medicare beneficiaries. The very low rates of utilization of these services suggest the need for focused systemic evaluations to identify and address the barriers and facilitators of this important patient-centered endeavor.

Relationships between reproductive hormones and maternal pregnancy physiology in women conceiving with or without in vitro fertilization

We evaluated maternal pregnancy adaptations and their relationships with circulating hormones in women who conceived with or without in vitro fertilization (IVF). Pregnancies were grouped by corpus luteum (CL) number: 1 CL with physiological plasma relaxin concentration (P_RLN; spontaneous pregnancies); 0 CL without circulating RLN (programmed cycles); >1 CL with elevated P_RLN (ovarian stimulation). Major findings were that declines in plasma osmolality (P_osm) and plasma sodium concentration ([Formula: see text]) were comparable in the 1 CL and 0 CL cohorts, correlated with plasma estradiol and progesterone concentrations but not P_RLN; gestational declines in plasma uric acid (UA) concentration (P_UA) were attenuated after IVF, especially programmed cycles, partly because of subdued increases of renal UA clearance; and P_RLN and cardiac output (CO) were inversely correlated when plasma estradiol concentration was below ∼2.5 ng/mL but positively correlated above ∼2.5 ng/mL. Unexpectedly, P_RLN and plasma sFLT1 (P_sFLT1) were directly correlated. Although P_sFLT1 and CO were not significantly associated, CO was positively correlated with plasma placental growth factor (PLGF) concentration after the first trimester, particularly in women who conceived with 0 CL. Major conclusions are that 1) circulating RLN was unnecessary for gestational falls in P_osm and [Formula: see text]; 2) P_RLN and CO were inversely correlated during early gestation, suggesting that P_RLN in the lower range may have contributed to systemic vasodilation, whereas at higher P_RLN RLN influence became self-limiting; 3) evidence for cooperativity between RLN and estradiol on gestational changes in CO was observed; and 4) after the first trimester in women who conceived without a CL, plasma PLGF concentration was associated with recovery of CO, which was impaired during the first trimester in this cohort.

Nonatherosclerotic Vascular Abnormalities Associated with Chronic Kidney Disease

Nonatherosclerotic vascular diseases are manifested by endothelial dysfunction, hypertension, vascular calcification, coronary microvascular dysfunction, and calciphylaxis. Unfortunately, there are no definitive treatments for many of these disorders other than hypertension. In addition, although hypertension is more difficult to treat in the chronic kidney disease population, it is necessary to try and target a blood pressure of less than 130/80 mm Hg through the use of aggressive angiotensin-converting enzyme inhibitors/angiotensin receptor blockers, diuretics, and other antihypertensive medications. New therapies are being actively investigated in an attempt to treat nonatherosclerotic vascular diseases in the chronic kidney disease population.

Pro Re Nata Antihypertensive Medications and Adverse Outcomes in Hospitalized Patients: A Propensity-Matched Cohort Study

[Figure: see text].

Association of early initiation of dialysis with all-cause and cardiovascular mortality: A propensity score weighted analysis of the United States Renal Data System

BACKGROUND

Early initiation of maintenance hemodialysis has been associated with excess mortality in some studies, but the effects on cardiovascular (CV) mortality has not been studied. Moreover, whether the increased mortality is due to co-morbidities or early initiation of dialysis is unclear. We used a propensity score weighted analysis of the United States Renal Data System (USRDS) to examine how the estimated glomerular filtration rate (eGFR) at initiation of dialysis affects total and CV mortality.

METHODS

Association between tertiles of eGFR at initiation of hemodialysis and all-cause and CV mortality were assessed in 676,196 adult patients who initiated hemodialysis between 2006 and 2014, using inverse probability of treatment weighting (IPTW) weighted multivariable regression models.

RESULTS

The intermediate (eGFR 8.7 to <13.0 mL/min) and early start groups (eGFR ≥13.0 mL/min) had a 42% and 93% increased all-cause mortality, respectively compared to late (eGFR < 8.7), start group (unadjusted hazard ratio (HR) = 1.42; 95% CI, 1.41-1.43 and HR = 1.93; 95%CI, 1.91-1.94, respectively). This association was attenuated but remained significant in propensity weighted multivariable analysis (adjusted HR = 1.13; 95%CI, 1.12-1.14 for intermediate and HR = 1.37; 95%CI, 1.36-1.39, for early start, respectively). The CV mortality was similarly increased (adjusted HR = 1.08; 95%CI, 1.07-1.10 and HR = 1.23; 95%CI, 1.21-1.24, for intermediate and early start, respectively). In patients with cystic kidney disease, all-cause mortality was increased with early start, but there were no differences in CV mortality between groups.

CONCLUSIONS

Early initiation of dialysis is associated with increased all-cause and CV mortality. Our observations support delaying hemodialysis according to the eGFR values.

Management of Cardiovascular Disease in Kidney Disease Study: Rationale and Design

INTRODUCTION

Atherosclerosis, inflammation, and vascular stiffness are prominent interrelated risk factors contributing to the high incidence of cardiovascular disease (CVD) in patients with CKD. Conventional CVD management strategies in CKD largely target atherosclerotic CVD and have had a limited impact on the cardiovascular mortality in this population. Multiple in vivo and in vitro studies and epidemiological evidence from the rheumatologic cohorts have shown that low-dose hydroxychloroquine has beneficial effects on inflammation, endothelial function, insulin sensitivity, and metabolic syndrome. Our recent proof-of-concept animal study showed that hydroxychloroquine has marked protection against atherosclerosis and vascular stiffness. We hypothesize that hydroxychloroquine has the potential to provide significant cardiovascular benefits in patients with CKD.

METHODS

The Management of Cardiovascular disease in Kidney disease study (NCT03636152) is a phase 2B, randomized, double-blind, placebo-controlled trial evaluating the effects of low-dose hydroxychloroquine therapy on the parameters of atherosclerosis, inflammation, and vascular stiffness in patients with CKD. The study plans to enroll 100 CKD patients estimated to be at high cardiovascular risk by a combination of low estimated glomerular filtration rate and albuminuria and treat them for 18 months with hydroxychloroquine or placebo in 1:1 allocation.

RESULTS

The study will assess the change in the total carotid plaque volume as measured by serial noncontrast carotid MRI as the primary outcome and the serial changes in plasma inflammation markers, vascular stiffness, renal function, and the composition characteristics of the carotid plaque as secondary outcome measures.

DISCUSSION/CONCLUSION

The results of this trial will provide the proof-of-applicability for hydroxychloroquine in the CVD in CKD. If positive, this trial should lead to phase-3 trials with clinical end points for this potentially transformative, novel, and inexpensive therapy for CVD in CKD.

Advancing Nephrology: Division Leaders Advise ASN

New treatments, new understanding, and new approaches to translational research are transforming the outlook for patients with kidney diseases. A number of new initiatives dedicated to advancing the field of nephrology-from value-based care to prize competitions-will further improve outcomes of patients with kidney disease. Because of individual nephrologists and kidney organizations in the United States, such as the American Society of Nephrology, the National Kidney Foundation, and the Renal Physicians Association, and international nephrologists and organizations, such as the International Society of Nephrology and the European Renal Association-European Dialysis and Transplant Association, we are beginning to gain traction to invigorate nephrology to meet the pandemic of global kidney diseases. Recognizing the timeliness of this opportunity, the American Society of Nephrology convened a Division Chief Retreat in Dallas, Texas, in June 2019 to address five key issues: (1) asserting the value of nephrology to the health system; (2) productivity and compensation; (3) financial support of faculty's and divisions' educational efforts; (4) faculty recruitment, retention, diversity, and inclusion; and (5) ensuring that fellowship programs prepare trainees to provide high-value nephrology care and enhance attraction of trainees to nephrology. Herein, we highlight the outcomes of these discussions and recommendations to the American Society of Nephrology.

Circulating endothelial cells as predictor of long-term mortality and adverse cardiovascular outcomes in hemodialysis patients

Circulating endothelial cells (CEC) are thought to be markers of endothelial injury. We hypothesized that the numbers of CEC may provide a novel means for predicting long-term survival and cardiovascular events in hemodialysis patients. 54 hemodialysis patients underwent enumeration of their CEC number. We retrospectively analyzed their survival and incidence of adverse cardiovascular events. 22 deaths (41%) were noted over the median follow up period of 3.56 years (IQR 1.43-12) and 6 were attributed to cardiovascular deaths (11%) of which 1 (4%) was in the low CEC (CEC<20 cells/ml) and 5 (19%) in the high CEC (CEC≥20 cells/ml) group. High CEC was associated with worse cardiovascular survival (p = 0.05) and adverse cardiac events (p = 0.01). In multivariate analysis, CEC >20 cells/ml was associated with a 4-fold increased risk of adverse cardiac events (OR, 4.16 [95% CI,1.38-12.54],p = 0.01) while all-cause mortality and cardiovascular mortality were not statistically different. In this hemodialysis population, a single measurement of CEC was a strong predictor of long term future adverse cardiovascular events. We propose that CEC may be a novel biomarker for assessing cardiovascular risk in dialysis patients.

Tubular Biomarkers and Chronic Kidney Disease Progression in SPRINT Participants

BACKGROUND

Kidney tubular atrophy on biopsy is a strong predictor of chronic kidney disease (CKD) progression, but tubular health is poorly quantified by traditional measures including estimated glomerular filtration rate (eGFR) and albuminuria. We hypothesized that urinary biomarkers of impaired tubule function would be associated with faster eGFR declines in persons with CKD.

METHODS

We measured baseline urine concentrations of uromodulin, β2-microglobulin (β2m), and α1-microglobulin (α1m) among 2,428 participants of the Systolic Blood Pressure Intervention Trial with an eGFR <60 mL/min/1.73 m2. We used linear mixed models to evaluate biomarker associations with annualized relative change in eGFR, stratified by randomization arm.

RESULTS

At baseline, the mean age was 73 ± 9 years and eGFR was 46 ± 11 mL/min/1.73 m2. In the standard blood pressure treatment arm, each 2-fold higher urinary uromodulin was associated with slower % annual eGFR decline (0.34 [95% CI: 0.08, 0.60]), whereas higher urinary β2m was associated with faster % annual eGFR decline (-0.10 [95% CI: -0.18, -0.02]) in multivariable-adjusted models including baseline eGFR and albuminuria. Associations were weaker and did not reach statistical significance in the intensive blood pressure treatment arm for either uromodulin (0.11 [-0.13, 0.35], p value for interaction by treatment arm = 0.045) or β2m (-0.01 [-0.08, 0.08], p value for interaction = 0.001). Urinary α1m was not independently associated with eGFR decline in the standard (0.01 [-0.22, 0.23]) or intensive (0.03 [-0.20, 0.25]) arm.

CONCLUSIONS

Among trial participants with hypertension and CKD, baseline measures of tubular function were associated with subsequent declines in kidney function, although these associations were diminished by intensive blood pressure control.

Maternal endothelial function, circulating endothelial cells, and endothelial progenitor cells in pregnancies conceived with or without in vitro fertilization

In women who conceived with or without assisted reproduction, we evaluated endothelial function by EndoPAT [reactive hyperemia index (RHI)], circulating numbers of endothelial cells (CEC) and endothelial progenitor cells (EPC), and their function before during and after pregnancy. In vitro fertilization (IVF) pregnancies were stratified by method of conception and corpus luteum (CL) number-controlled ovarian stimulation (>1 CL) or programmed (0 CL) cycles and spontaneous singleton pregnancies (1 CL). We observed 1) comparable gestational decline of RHI in the three participant groups secondary to gestational rise of baseline preocclusion pulse-wave amplitude (PWA) incorporated into the RHI calculation by EndoPAT software; 2) progressive rise in "normalized" RHI throughout pregnancy (calculated by substituting prepregnancy baseline preocclusion PWA into the RHI equation), greater in spontaneous conception vs. IVF cohorts; 3) similar gestational increase of maximum PWA and time to maximum PWA after the ischemia stimulus among the three participant groups; 4) modest gestational increase of ischemia response (reactive hyperemia) in the spontaneous conception group and no change or significant decline, respectively, in women who conceived using programmed or controlled ovarian stimulation cycles; 5) enhanced basal nitric oxide production by early (primitive) outgrowth EPC during pregnancy in women who conceived spontaneously, but not through IVF; and 6) gestational increase in CEC in all three participant cohorts, more pronounced in women who conceived by IVF using programmed cycles. On balance, the evidence supported enhanced endothelial function during pregnancy in spontaneous conceptions but less so in IVF pregnancies using either controlled ovarian stimulation or programmed cycles.

Engineering magnetic nanoparticles and their integration with microfluidics for cell isolation

Isolation of cancer cells, bacteria, and viruses from peripheral blood has important applications in cancer diagnosis, therapy monitoring, and drug development. Magnetic particles functionalized with antibodies that target receptors of cancer cells have been shown to isolate such entities using magnetic field gradients. Here, we report enhancement in capture efficiency and specificity by engineering magnetic nanoparticles and integrating them with microfluidics for the enumeration of tumor cells. Nanoparticles were made from iron oxide, coated with poly(ethylene glycol), and conjugated through avidin-biotin chemistry with antibody specifically against epithelial cell adhesion molecule (EpCAM). On exposure of targeted nanoparticles to tumor cells, specific uptake by EpCAM-expressing tumor cells (e.g., BxPC3, a pancreatic cancer cell) was observed, whereas there was negligible uptake by cells with low EpCAM expression (e.g., CCRF-CEM, a leukemia cell). Using an arrangement of magnets called a Halbach array, capture efficiency and specificity towards BxPC3 cells tagged with magnetic nanoparticles were enhanced, compared to conditions without the magnetic field gradient and/or without magnetic nanoparticles, either in buffer or in whole blood. These results illustrate that engineered magnetic nanoparticles and their integration with microfluidics have great potential for tumor cell enumeration and cancer prognosis.

The utility of trough mycophenolic acid levels for the management of lupus nephritis

Background

Monitoring of mycophenolic acid (MPA) levels may be useful for effective mycophenolate mofetil (MMF) dosing. However, whether commonly obtained trough levels are an acceptable method of surveillance remains debatable. We hypothesized that trough levels of MPA would be a poor predictor of area under the curve (AUC) for MPA.

Methods

A total of 51 patients with lupus nephritis who were on MMF 1500 mg twice a day and had a 4-h AUC done were included in this study. MPA levels were measured prior to (C0) and at 1 (C1), 2 (C2) and 4 (C4) h, followed by 1500 mg of MMF. The MPA AUC values were calculated using the linear trapezoidal rule. Regression analysis was used to examine the relationship between the MPA trough and AUC. Differences in the MPA trough and AUC between different clinical and demographic categories were compared using t-tests.

Results

When grouped by tertiles there was significant overlap in MPA, AUC 0-4 and MPA trough in all tertiles. Although there was a statistically significant correlation between MPA trough levels and AUC, this association was weak and accounted for only 30% of the variability in MPA trough levels. This relationship might be even more unreliable in men than women. The use of angiotensin-converting enzyme inhibitors or angiotensin receptor blockers was associated with increased MPA trough levels and AUC at 0-4 h (AUC0-4).

Conclusion

Trough levels of MPA do not show a strong correlation with AUC. In clinical situations where MPA levels are essential to guide therapy, an AUC0-4 would be a better indicator of the adequacy of treatment.

Increased Preeclampsia Risk and Reduced Aortic Compliance With In Vitro Fertilization Cycles in the Absence of a Corpus Luteum

In vitro fertilization involving frozen embryo transfer and donor oocytes increases preeclampsia risk. These in vitro fertilization protocols typically yield pregnancies without a corpus luteum (CL), which secretes vasoactive hormones. We investigated whether in vitro fertilization pregnancies without a CL disrupt maternal circulatory adaptations and increase preeclampsia risk. Women with 0 (n=26), 1 (n=23), or >1 (n=22) CL were serially evaluated before, during, and after pregnancy. Because increasing arterial compliance is a major physiological adaptation in pregnancy, we assessed carotid-femoral pulse wave velocity and transit time. In a parallel prospective cohort study, obstetric outcomes for singleton livebirths achieved with autologous oocytes were compared between groups by CL number (n=683). The expected decline in carotid-femoral pulse wave velocity and rise in carotid-femoral transit time during the first trimester were attenuated in the 0-CL compared with combined single/multiple-CL cohorts, which were similar (group-time interaction: P=0.06 and 0.03, respectively). The blunted changes of carotid-femoral pulse wave velocity and carotid-femoral transit time from prepregnancy in the 0-CL cohort were most striking at 10 to 12 weeks of gestation ( P=0.01 and 0.006, respectively, versus 1 and >1 CL). Zero CL was predictive of preeclampsia (adjusted odds ratio, 2.73; 95% CI, 1.14-6.49) and preeclampsia with severe features (6.45; 95% CI, 1.94-25.09) compared with 1 CL. Programmed frozen embryo transfer cycles (0 CL) were associated with higher rates of preeclampsia (12.8% versus 3.9%; P=0.02) and preeclampsia with severe features (9.6% versus 0.8%; P=0.002) compared with modified natural frozen embryo transfer cycles (1 CL). In common in vitro fertilization protocols, absence of the CL perturbed the maternal circulation in early pregnancy and increased the incidence of preeclampsia.

Potential influence of the corpus luteum on circulating reproductive and volume regulatory hormones, angiogenic and immunoregulatory factors in pregnant women

Cardiovascular function is impaired and preeclampsia risk elevated in women conceiving by in vitro fertilization (IVF) in the absence of a corpus luteum (CL). Here, we report the serial evaluation of hormones and other circulating factors in women who conceived with (or without) IVF. After a prepregnancy baseline, the study participants (n = 19-24/cohort) were evaluated six times during pregnancy and once postpartum (~1.6 yr). IVF pregnancies were stratified by protocol and CL number, i.e., ovarian stimulation (>1 CL) or hypothalamic-pituitary suppression (0 CL) versus spontaneous conceptions (1 CL). Results include the following: 1) relaxin was undetectable throughout pregnancy (including late gestation) in the 0 CL cohort, but markedly elevated in ~50% of women in the >1 CL cohort; 2) progesterone, plasma renin activity, and aldosterone transiently surged at 5-6 gestational weeks in the >1 CL group; 3) soluble vascular endothelial growth factor-1 (sFLT-1) abruptly increased between 5-6 and 7-9 gestational weeks in all three participant cohorts, producing a marked elevation in sFLT-1/PLGF (placental growth factor) ratio exceeding any other time point during pregnancy; 4) sFLT-1 was higher throughout most of gestation in both IVF cohorts with or without abnormal obstetrical outcomes; 5) during pregnancy, C-reactive protein (CRP) increased in 0 and 1 CL, but not >1 CL cohorts; and 6) plasma protein, but not hemoglobin, was lower in the >1 CL group throughout gestation. The findings highlight that, compared with spontaneously conceived pregnancy, the maternal milieu of IVF pregnancy is not physiologic, and the specific perturbations vary according to IVF protocol and CL status.

Wave reflections and global arterial compliance during normal human pregnancy

Profound changes occur in the maternal circulation during pregnancy. Routine measures of arterial function - central systolic pressure (CSP) and augmentation index (AIx) - decline during normal human pregnancy. The objectives of this study were twofold: (1) explore wave reflection indices besides CSP and AIx that are not routinely reported, if at all, during normal human pregnancy; and (2) compare wave reflection indices and global arterial compliance (gAC) obtained from carotid artery pressure waveforms (CAPW) as a surrogate for aortic pressure waveforms (AOPW) versus AOPW synthesized from radial artery pressure waveforms (RAPW) using a generalized transfer function. To our knowledge, a comparison of these two methods has not been previously evaluated in the context of pregnancy. Ten healthy women with normal singleton pregnancies were studied using applanation tonometry (SphygmoCor) at pre-conception, and then during 10-12 and 33-35 gestational weeks. CSP and AIx declined, and gAC increased during pregnancy as previously reported. As a consequence of the rise in gAC, the return of reflected waves of lesser magnitude from peripheral reflection sites to the aorta was delayed that, in turn, reduced systolic duration of reflected waves, augmentation index, central systolic pressure, LV wasted energy due to reflected waves, and increased brachial-central pulse pressure. For several wave reflection indices, those derived from CAPW as a surrogate for AOPW versus RAPW using a generalized transfer function registered greater gestational increases of arterial compliance. This discordance may reflect imprecision of the generalized transfer function for some waveform parameters, though potential divergence of carotid artery and aortic pressure waveforms during pregnancy cannot be excluded.

Maternal Cardiovascular Dysregulation During Early Pregnancy After In Vitro Fertilization Cycles in the Absence of a Corpus Luteum

Commonly used in vitro fertilization protocols produce pregnancies without a corpus luteum (CL), a major source of reproductive hormones. In vitro fertilization pregnancies without a CL showed deficient gestational increases of central (aortic) arterial compliance during the first trimester and were at increased risk for developing preeclampsia. Here, we investigated whether there was generalized impairment of cardiovascular adaptation in in vitro fertilization pregnancies without a CL compared with pregnancies conceived spontaneously or through ovarian stimulation, which lead to 1 and >1 CL, respectively (n=19-26 participants per cohort). Prototypical maternal cardiovascular adaptations of gestation were serially evaluated noninvasively, initially during the follicular phase before conception, 6× in pregnancy, and then, on average, 1.6 years post-partum. The expected increases of cardiac output, left atrial dimension, peak left ventricular filling velocity in early diastole (E wave velocity), peripheral/central arterial pulse pressure ratio, and global AC, as well as decrease in augmentation index were significantly attenuated or absent during the first trimester in women who conceived without a CL, when compared with the 1 and >1 CL cohorts, which were comparable. Thereafter, these cardiovascular measures showed recovery in the 0 CL group except for E wave velocity, which remained depressed. These results provided strong support for a critical role of CL factor(s) in the transformation of the maternal cardiovascular system in early gestation. Regimens that lead to the development of a CL or replacement of missing CL factor(s) may be indicated to improve cardiovascular function and reduce preeclampsia risk in in vitro fertilization pregnancies.

Antihypertensive therapy prescribing patterns and correlates of blood pressure control among hypertensive patients with chronic kidney disease

We used electronic health records (EHRs) data from 5658 ambulatory chronic kidney disease (CKD) patients with hypertension and prescribed antihypertensive therapy to examine antihypertensive drug prescribing patterns, blood pressure (BP) control, and risk factors for resistant hypertension (RHTN) in a real-world setting. Two-thirds of CKD patients and three-fourths of those with proteinuria were prescribed guideline-recommended renoprotective agents including an angiotensin-converting enzyme inhibitor (ACEI) or an angiotensin receptor blocker (ARB); however, one-third were not prescribed an ACEI or ARB. CKD patients, particularly those with stages 1-2 CKD, who were prescribed regimens including beta-blocker (BB) + diuretic or ACEI/ARB + BB + diuretic were more likely to have controlled BP (<140/90 mm Hg) compared to those prescribed other combinations. Risk factors for RHTN included African American race and major comorbidities. Clinicians may use these findings to tailor antihypertensive therapy to the needs of each patient, including providing CKD stage-specific treatment, and better identify CKD patients at risk of RHTN.

Development of a personalized diagnostic model for kidney stone disease tailored to acute care by integrating large clinical, demographics and laboratory data: the diagnostic acute care algorithm - kidney stones (DACA-KS)

Background

Kidney stone (KS) disease has high, increasing prevalence in the United States and poses a massive economic burden. Diagnostics algorithms of KS only use a few variables with a limited sensitivity and specificity. In this study, we tested a big data approach to infer and validate a ‘multi-domain’ personalized diagnostic acute care algorithm for KS (DACA-KS), merging demographic, vital signs, clinical, and laboratory information.

Methods

We utilized a large, single-center database of patients admitted to acute care units in a large tertiary care hospital. Patients diagnosed with KS were compared to groups of patients with acute abdominal/flank/groin pain, genitourinary diseases, and other conditions. We analyzed multiple information domains (several thousands of variables) using a collection of statistical and machine learning models with feature selectors. We compared sensitivity, specificity and area under the receiver operating characteristic (AUROC) of our approach with the STONE score, using cross-validation.

Results

Thirty eight thousand five hundred and ninety-seven distinct adult patients were admitted to critical care between 2001 and 2012, of which 217 were diagnosed with KS, and 7446 with acute pain (non-KS). The multi-domain approach using logistic regression yielded an AUROC of 0.86 and a sensitivity/specificity of 0.81/0.82 in cross-validation. Increase in performance was obtained by fitting a super-learner, at the price of lower interpretability. We discussed in detail comorbidity and lab marker variables independently associated with KS (e.g. blood chloride, candidiasis, sleep disorders).

Conclusions

Although external validation is warranted, DACA-KS could be integrated into electronic health systems; the algorithm has the potential used as an effective tool to help nurses and healthcare personnel during triage or clinicians making a diagnosis, streamlining patients’ management in acute care.

Activation of the β-common receptor by erythropoietin impairs acetylcholine-mediated vasodilation in mouse mesenteric arterioles

Clinically, erythropoietin (EPO) is known to increase systemic vascular resistance and arterial blood pressure. However, EPO stimulates the production of the potent vasodilator, nitric oxide (NO), in culture endothelial cells. The mechanism by which EPO causes vasoconstriction despite stimulating NO production may be dependent on its ability to activate two receptor complexes, the homodimeric EPO (EPOR2 ) and the heterodimeric EPOR/β-common receptor (βCR). The purpose of this study was to investigate the contribution of each receptor to the vasoactive properties of EPO. First-order, mesenteric arteries were isolated from 16-week-old male C57BL/6 mice, and arterial function was studied in pressure arteriographs. To determine the contribution of each receptor complex, EPO-stimulating peptide (ESP), which binds and activates the heterodimeric EPOR/βCR complex, and EPO, which activates both receptors, were added to the arteriograph chamber 20 min prior to evaluation of endothelium-dependent (acetylcholine, bradykinin, A23187) and endothelium-independent (sodium nitroprusside) vasodilator responses. Only ACh-induced vasodilation was impaired in arteries pretreated with EPO or ESP. EPO and ESP pretreatment abolished ACh-induced vasodilation by 100% and 60%, respectively. EPO and ESP did not affect endothelium-independent vasodilation by SNP. Additionally, a novel βCR inhibitory peptide (βIP), which was computationally developed, prevented the impairment of acetylcholine-induced vasodilation by EPO and ESP, further implicating the EPOR/βCR complex. Last, pretreatment with either EPO or ESP did not affect vasoconstriction by phenylephrine and KCl. Taken together, these findings suggest that acute activation of the heterodimeric EPOR/βCR in endothelial cells leads to a selective impairment of ACh-mediated vasodilator response in mouse mesenteric resistance arteries.

Not all that is red is blood: a curious case of chromaturia

Hydroxocobalamin causes reddish discoloration of the urine, mimicking hematuria. Clinicians should be aware of this common side effect of the rarely used drug to prevent unnecessary consultations and work-up. Additional benign causes of red urine include foods such as beets, rhubarb, and medications such as rifampin, phenazopyridine.

Computational design and experimental characterization of a novel β-common receptor inhibitory peptide

In short-term animal models of ischemia, erythropoietin (EPO) signaling through the heterodimeric EPO receptor (EPOR)/β-common receptor (βCR) is believed to elicit tissue protective effects. However, large, randomized, controlled trials demonstrate that targeting a higher hemoglobin level by administering higher doses of EPO, which are more likely to activate the heterodimeric EPOR/βCR, is associated with an increase in adverse cardiovascular events. Thus, inhibition of long-term activation of the βCR may have therapeutic implications. This study aimed to design and evaluate the efficacy of novel computationally designed βCR inhibitory peptides (βIP). These novel βIPs were designed based on a truncated portion of Helix-A from EPO, specifically residues 11-26 (VLERYLLEAKEAEKIT). Seven novel peptides (P1 to P7) were designed. Peptide 7 (P7), VLERYLHEAKHAEKIT, demonstrated the most robust inhibitory activity. We also report here the ability of P7 to inhibit βCR-induced nitric oxide (NO) production and angiogenesis in human umbilical vein endothelial cells (HUVECs). Specifically, we found that P7 βIP completely abolished EPO-induced NO production. The inhibitory effect could be overcome with super physiological doses of EPO, suggesting a competitive inhibition. βCR-induced angiogenesis in HUVEC's was also abolished with treatment of P7 βIP, but P7 βIP did not inhibit vascular endothelial growth factor (VEGF)-induced angiogenesis. In addition, we demonstrate that the novel P7 βIP does not inhibit EPO-induced erythropoiesis with use of peripheral blood mononuclear cells (PBMCs). These results, for the first time, describe a novel, potent βCR peptide inhibitor that inhibit the actions of the βCR without affecting erythropoiesis.

Persistent inflammation, immunosuppression, and catabolism and the development of chronic critical illness after surgery

As early as the 1990s, chronic critical illness, a distinct syndrome of persistent high-acuity illness requiring management in the ICU, was reported under a variety of descriptive terms including the "neuropathy of critical illness," "myopathy of critical illness," "ICU-acquired weakness," and most recently "post-intensive care unit syndrome." The widespread implementation of targeted shock resuscitation, improved organ support modalities, and evidence-based protocolized ICU care has resulted in significantly decreased in-hospital mortality within surgical ICUs, specifically by reducing early multiple organ failure deaths. However, a new phenotype of multiple organ failure has now emerged with persistent but manageable organ dysfunction, high resource utilization, and discharge to prolonged care facilities. This new multiple organ failure phenotype is now clinically associated with the rapidly increasing incidence of chronic critical illness in critically ill surgery patients. Although the underlying pathophysiology driving chronic critical illness remains incompletely described, the persistent inflammation, immunosuppression, and catabolism syndrome has been proposed as a mechanistic framework in which to explain the increased incidence of chronic critical illness in surgical ICUs. The purpose of this review is to provide a historic perspective of the epidemiologic evolution of multiple organ failure into persistent inflammation, immunosuppression, and catabolism syndrome; describe the mechanism that drives and sustains chronic critical illness, and review the long-term outcomes of surgical patients who develop chronic critical illness.

Gender, blood pressure, and cardiovascular and renal outcomes in adults with hypertension from the Systolic Blood Pressure Intervention Trial

BACKGROUND

To determine if the effects of intensive lowering of systolic blood pressure (goal of less than 120 mmHg) versus standard lowering (goal of less than 140 mmHg) upon cardiovascular, renal, and safety outcomes differed by gender.

METHODS

Nine thousand three hundred and sixty-one men and women aged 50 years or older with systolic blood pressure of 130 mmHg or greater, taking 0-4 antihypertensive medications, and with increased risk of cardiovascular disease, but free of diabetes, were randomly assigned to either a systolic blood pressure target of less than 120 mmHg (intensive treatment) or a target of less than 140 mmHg (standard treatment). The primary composite outcome encompassed incident myocardial infarction, heart failure, other acute coronary syndromes, stroke, or cardiovascular-related death. All-cause mortality, renal outcomes, and serious adverse events were also assessed.

RESULTS

Compared with the standard treatment group, the primary composite outcome in the intensive treatment group was reduced by 16% [hazard ratio 0.84 (0.61-1.13)] in women, and by 27% in men [hazard ratio 0.73 (0.59-0.89), P value for interaction between treatment and gender is 0.45]. Similarly, the effect of the intensive treatment on individual components of the primary composite outcome, renal outcomes, and overall serious adverse events was not significantly different according to gender.

CONCLUSION

In adults with hypertension but not with diabetes, treatment to a systolic blood pressure goal of less than 120 mmHg, compared with a goal of less than 140 mmHg, resulted in no heterogeneity of effect between men and women on cardiovascular or renal outcomes, or on rates of serious adverse events.ClinicalTrials.gov number, NCT01206062.

Comparison of multiple non-invasive methods of measuring cardiac output during pregnancy reveals marked heterogeneity in the magnitude of cardiac output change between women

Various non-invasive methods are available to measure cardiac output (CO) during pregnancy. We compared serial measures of CO using various methods to determine which provided the least variability. Ten patients with spontaneous pregnancy had estimation of CO at baseline prior to becoming pregnant and at the end of the first and third trimesters. Echocardiographic data were used to estimate CO using the Teichholz method, Simpson's biplane method, and the Doppler determined velocity time integral (VTI) method. In addition, a Bioz Dx device was used to estimate CO by impedance cardiography. CO estimated with the VTI method had the lowest beat-to-beat variability. CO estimated with the VTI method was higher than CO estimated with the 2D-Teichholz method and Simpson's method. The percent change in CO during pregnancy was similar for all echo methods (VTI, Teichholz, and Simpson's biplane). Baseline CO determined with impedance cardiography was higher than CO determined with the VTI method. However, change in CO during pregnancy was significantly lower when measured with impedance cardiography. There was marked heterogeneity in the degree of rise in CO during the first trimester (-3 to 55%). The wide variation in the gestational rise in CO was unexpected, and at least in part secondary to variable increase in heart rate. We recommend the use of the Doppler determined VTI method for the estimation of CO in pregnancy.

Sepsis and Critical Illness Research Center investigators: protocols and standard operating procedures for a prospective cohort study of sepsis in critically ill surgical patients

INTRODUCTION

Sepsis is a common, costly and morbid cause of critical illness in trauma and surgical patients. Ongoing advances in sepsis resuscitation and critical care support strategies have led to improved in-hospital mortality. However, these patients now survive to enter state of chronic critical illness (CCI), persistent low-grade organ dysfunction and poor long-term outcomes driven by the persistent inflammation, immunosuppression and catabolism syndrome (PICS). The Sepsis and Critical Illness Research Center (SCIRC) was created to provide a platform by which the prevalence and pathogenesis of CCI and PICS may be understood at a mechanistic level across multiple medical disciplines, leading to the development of novel management strategies and targeted therapies.

METHODS

Here, we describe the design, study cohort and standard operating procedures used in the prospective study of human sepsis at a level 1 trauma centre and tertiary care hospital providing care for over 2600 critically ill patients annually. These procedures include implementation of an automated sepsis surveillance initiative, augmentation of clinical decisions with a computerised sepsis protocol, strategies for direct exportation of quality-filtered data from the electronic medical record to a research database and robust long-term follow-up.

ETHICS AND DISSEMINATION

This study has been registered at ClinicalTrials.gov, approved by the University of Florida Institutional Review Board and is actively enrolling subjects. Dissemination of results is forthcoming.

Conditional Deletion of Bmal1 Accentuates Microvascular and Macrovascular Injury

The brain and muscle aryl hydrocarbon receptor nuclear translocator-like protein (BMAL)-1 constitutes a major transcriptional regulator of the circadian clock. Here, we explored the impact of conditional deletion of Bmal1 in endothelium and hematopoietic cells in murine models of microvascular and macrovascular injury. We used two models of Bmal1fx/fx;Tek-Cre mice, a retinal ischemia/reperfusion model and a neointimal hyperplasia model of the femoral artery. Eyes were enumerated for acellular capillaries and were stained for oxidative damage markers using nitrotyrosine immunohistochemistry. LSK (lineage-negative, stem cell antigen-1-positive, c-Kit-positive) cells were quantified and proliferation assessed. Hematopoiesis is influenced by innervation to the bone marrow, which we assessed using IHC analysis. The number of acellular capillaries increased threefold, and nitrotyrosine staining increased 1.5-fold, in the retinas of Bmal1fx/fx;Tek-Cre mice. The number of LSK cells from the Bmal1fx/fx;Tek-Cre mice decreased by 1.5-fold and was accompanied by a profound decrease in proliferative potential. Bmal1fx/fx;Tek-Cre mice also exhibited evidence of bone marrow denervation, demonstrating a loss of neurofilament-200 staining. Injured femoral arteries showed a 20% increase in neointimal hyperplasia compared with similarly injured wild-type controls. Our study highlights the importance of the circadian clock in maintaining vascular homeostasis and demonstrates that specific deletion of BMAL1 in endothelial and hematopoietic cells results in phenotypic features similar to those of diabetes.

Case Report of Spontaneous Remission of Biopsy-Proven Idiopathic Immune Complex-Mediated Membranoproliferative Glomerulonephritis

Membranoproliferative glomerulonephritis (MPGN) is a histopathologic diagnosis causing microscopic hematuria, nephrotic range proteinuria, and chronic renal failure. Current understanding divides pathogenesis into two broad categories: immune complex mediated and complement mediated (now termed C3 glomerulopathy). The term idiopathic immune complex-mediated MPGN would apply to a patient without an identifiable source of immune complex production and no evidence of C3 glomerulopathy. Presented is a patient with idiopathic immune complex mediated MPGN and her clinical course. The patient opted for conservative therapy with losartan, carvedilol, chlorthalidone, and atorvastatin. Nephrotic range proteinuria of 8.7 g per day resolved over 5 months, with improvement of serum from 3.3 to 1.2 mg/dL. Remission continues at follow-up 21 months after biopsy. For idiopathic immune complex-mediated MPGN, resorting to empiric immunosuppression therapy may not be the best option. As this patient demonstrates, a conservative approach of blood pressure control with anti-renin-angiotensin agents, control of lipids, and watchful follow-up can be successful.

Acute and Chronic Kidney Disease and Cardiovascular Mortality After Major Surgery

OBJECTIVE

The aim of the study was to determine the long-term cardiovascular-specific mortality in patients with acute kidney injury (AKI) or chronic kidney disease (CKD) after major surgery.

BACKGROUND

In surgical patients, pre-existing CKD and postoperative AKI are associated with increases in all-cause mortality.

METHODS

In a single-center cohort of 51,457 adult surgical patients undergoing major inpatient surgery, long-term cardiovascular-specific mortality was modeled using a multivariable subdistributional hazards model while treating any other cause of death as a competing risk and accounting for the progression to end-stage renal disease (ESRD) after discharge. Pre-existing CKD and ESRD, and postoperative AKI were the main independent predictors.

RESULTS

Before the admission, 4% and 8% of the cohort had pre-existing ESRD and CKD not requiring renal replacement therapy, respectively. During hospitalization, 39% developed AKI. At 10-year follow-up, adjusted cardiovascular-specific mortality estimates were 6%, 11%, 12%, 19%, and 27% for patients with no kidney disease, AKI with no CKD, CKD with no AKI, AKI with CKD, and ESRD, respectively (P < 0.001). This association remained after excluding 916 patients who progressed to ESRD after discharge, although it was significantly amplified among them. Compared with patients having no kidney disease, adjusted hazard ratios for cardiovascular mortality were significantly higher among patients with kidney disease, ranging from 1.95 (95% confidence interval, 1.80-2.11) for patients with de novo AKI to 5.70 (95% confidence interval, 5.00-6.49) for patients with pre-existing ESRD.

CONCLUSIONS

Both AKI and CKD were associated with higher long-term cardiovascular-specific mortality compared with patients having no kidney disease.

High sensitivity C-reactive protein in systemic lupus erythematosus: relation to disease activity, clinical presentation and implications for cardiovascular risk

Measurement of high sensitivity C-reactive protein (hs-CRP), has been used in the assessment of disease activity in numerous rheumatic conditions including systemic lupus erythematosus (SLE). However, the utility of hs-CRP measurement in patients with lupus is uncertain. This study examined if hs-CRP can be used to assess disease activity, severity and cardiovascular risk in SLE. Serum samples from 601 visits of 213 SLE patients and 134 controls were analysed for hs-CRP by nephelometry. Detailed demographic data were obtained from all subjects and medication history and key laboratory parameters were collected. Disease activity was assessed using the SLEDAI. High sensitivity CRP was not associated with disease activity (SLEDAI), number of ACR SLE criteria or presence of any particular organ involvement. hs-CRP levels were significantly correlated with standard cardiovascular risk factors including body weight ( P = 0.0002), hypertension ( P = 0.001), and apolipoprotein A-I ( P < 0.0001). Interestingly an inverse correlation was seen between hs-CRP levels and antimalarial use ( P = 0.0018). Our results suggest that measurement of hs-CRP, though not valuable as marker of disease activity in SLE may be of some use in the assessment of cardiovascular risk. We speculate that antimalarials may help to reduce cardiovascular risk in patients with SLE.

Impact of Hydroxychloroquine on Atherosclerosis and Vascular Stiffness in the Presence of Chronic Kidney Disease

Cardiovascular disease is the largest cause of morbidity and mortality among patients with chronic kidney disease (CKD) and end-stage kidney disease, with nearly half of all deaths attributed to cardiovascular disease. Hydroxychloroquine (HCQ), an anti-inflammatory drug, has been shown to have multiple pleiotropic actions relevant to atherosclerosis. We conducted a proof-of-efficacy study to evaluate the effects of hydroxychloroquine in an animal model of atherosclerosis in ApoE knockout mice with and without chronic kidney disease. Forty male, 6-week-old mice were divided into four groups in a 2 x 2 design: sham placebo group; sham treatment group; CKD placebo group; and CKD treatment group. CKD was induced by a two-step surgical procedure. All mice received a high-fat diet through the study duration and were sacrificed after 16 weeks of therapy. Mice were monitored with ante-mortem ultrasonic echography (AUE) for atherosclerosis and vascular stiffness and with post-mortem histology studies for atherosclerosis. Therapy with HCQ significantly reduced the severity of atherosclerosis in CKD mice and sham treated mice. HCQ reduced the area of aortic atherosclerosis on en face examination by approximately 60% in HCQ treated groups compared to the non-treated groups. Additionally, therapy with HCQ resulted in significant reduction in vascular endothelial dysfunction with improvement in vascular elasticity and flow patterns and better-preserved vascular wall thickness across multiple vascular beds. More importantly, we found that presence of CKD had no mitigating effect on HCQ's anti-atherosclerotic and vasculoprotective effects. These beneficial effects were not due to any significant effect of HCQ on inflammation, renal function, or lipid profile at the end of 16 weeks of therapy. This study, which demonstrates structural and functional protection against atherosclerosis by HCQ, provides a rationale to evaluate its use in CKD patients. Further studies are needed to define the exact mechanisms through which HCQ confers these benefits.

DNA Aptamer Assembly as a Vascular Endothelial Growth Factor Receptor Agonist

Controlling receptor-mediated processes in cells is paramount in many research areas. The activity of small molecules and growth factors is difficult to control and can lead to off-target effects through the activation of nonspecific receptors as well as binding affinity to nonspecific cell types. In this study, we report the development of a molecular trigger in the form of a divalent nucleic acid aptamer assembly toward vascular endothelial growth factor receptor-2 (VEGFR2). The assembly binds to VEGFR2 and functions as a receptor agonist with targeted receptor binding, promoting receptor phosphorylation, activation of the downstream Akt pathway, upregulation of endothelial nitric oxide synthase, and endothelial cell capillary tube formation. The agonist action we report makes this aptamer construct a promising strategy to control VEGFR2-mediated cell signaling.

The effect of the addition of allopurinol on blood pressure control in African Americans treated with a thiazide-like diuretic

We tested the hypothesis that xanthine oxidase inhibition among African Americans receiving the thiazide-type diuretic chlorthalidone may improve blood pressure control with fewer hyperuricemia-related side effects. We performed a randomized, double-blind, placebo-controlled study of African Americans with Stage 1 hypertension without clinically significant renal disease. One hundred fifty African American men or women between the ages of 18 and 65 years who met the exclusion/inclusion criteria with untreated or treated hypertension were started on chlorthalidone (25 mg/d) and potassium chloride. After a 5-week run-in on chlorthalidone, baseline testing was performed and they were randomized to allopurinol (300 mg/dL) or placebo with doses adjusted based on uric acid levels and followed for 8 weeks. One hundred ten subjects completed the study. Baseline systolic blood pressures after the 5-week chlorthalidone run-in were 119.9 ± 13.6 in the allopurinol group and 117 ± 11.2 in the placebo group indicating excellent blood pressure control with the single agent. After at least 4 week postrandomization, the difference in mean change in systolic blood pressure in allopurinol less placebo from visits 5 to 3 was 4.3 mm Hg (95% confidence interval, -0.2 to 8.7; P = .059). The difference in mean change in uric acid levels over the same period was 2.1 mg/dL (95% confidence interval, 1.7-2.6; P < .001). The use of chlorthalidone with or without allopurinol resulted in excellent blood pressure control. The addition of allopurinol tended to improve clinic blood pressure, but the difference from the group receiving chlorthalidone alone was not statistically significant.