Incident heart failure in chronic kidney disease: proteomics informs biology and risk stratification.

BACKGROUND AND AIMS: Incident heart failure (HF) among individuals with chronic kidney disease (CKD) incurs hospitalizations that burden patients and health care systems. There are few preventative therapies, and the Pooled Cohort equations to Prevent Heart Failure (PCP-HF) perform poorly in the setting of CKD. New drug targets and better risk stratification are urgently needed. METHODS: In this analysis of incident HF, SomaScan V4.0 (4638 proteins) was analysed in 2906 participants of the Chronic Renal Insufficiency Cohort (CRIC) with validation in the Atherosclerosis Risk in Communities (ARIC) study. The primary outcome was 14-year incident HF (390 events); secondary outcomes included 4-year HF (183 events), HF with reduced ejection fraction (137 events), and HF with preserved ejection fraction (165 events). Mendelian randomization and Gene Ontology were applied to examine causality and pathways. The performance of novel multi-protein risk models was compared to the PCP-HF risk score. RESULTS: Over 200 proteins were associated with incident HF after adjustment for estimated glomerular filtration rate at P < 1 × 10-5. After adjustment for covariates including N-terminal pro-B-type natriuretic peptide, 17 proteins remained associated at P < 1 × 10-5. Mendelian randomization associations were found for six proteins, of which four are druggable targets: FCG2B, IGFBP3, CAH6, and ASGR1. For the primary outcome, the C-statistic (95% confidence interval [CI]) for the 48-protein model in CRIC was 0.790 (0.735, 0.844) vs. 0.703 (0.644, 0.762) for the PCP-HF model (P = .001). C-statistic (95% CI) for the protein model in ARIC was 0.747 (0.707, 0.787). CONCLUSIONS: Large-scale proteomics reveal novel circulating protein biomarkers and potential mediators of HF in CKD. Proteomic risk models improve upon the PCP-HF risk score in this population.

Assessing chromatin relocalization in 3D using the patient rule induction method.

Three-dimensional (3D) genome architecture is critical for numerous cellular processes, including transcription, while certain conformation-driven structural alterations are frequently oncogenic. Inferring 3D chromatin configurations has been advanced by the emergence of chromatin conformation capture assays, notably Hi-C, and attendant 3D reconstruction algorithms. These have enhanced understanding of chromatin spatial organization and afforded numerous downstream biological insights. Until recently, comparisons of 3D reconstructions between conditions and/or cell types were limited to prescribed structural features. However, multiMDS, a pioneering approach developed by Rieber and Mahony (2019). that performs joint reconstruction and alignment, enables quantification of all locus-specific differences between paired Hi-C data sets. By subsequently mapping these differences to the linear (1D) genome the identification of relocalization regions is facilitated through the use of peak calling in conjunction with continuous wavelet transformation. Here, we seek to refine this approach by performing the search for significant relocalization regions in terms of the 3D structures themselves, thereby retaining the benefits of 3D reconstruction and avoiding limitations associated with the 1D perspective. The search for (extreme) relocalization regions is conducted using the patient rule induction method (PRIM). Considerations surrounding orienting structures with respect to compartmental and principal component axes are discussed, as are approaches to inference and reconstruction accuracy assessment. The illustration makes recourse to comparisons between four different cell types.

Proteomic cardiovascular risk assessment in chronic kidney disease.

AIMS: Chronic kidney disease (CKD) is widely prevalent and independently increases cardiovascular risk. Cardiovascular risk prediction tools derived in the general population perform poorly in CKD. Through large-scale proteomics discovery, this study aimed to create more accurate cardiovascular risk models. METHODS AND RESULTS: Elastic net regression was used to derive a proteomic risk model for incident cardiovascular risk in 2182 participants from the Chronic Renal Insufficiency Cohort. The model was then validated in 485 participants from the Atherosclerosis Risk in Communities cohort. All participants had CKD and no history of cardiovascular disease at study baseline when ∼5000 proteins were measured. The proteomic risk model, which consisted of 32 proteins, was superior to both the 2013 ACC/AHA Pooled Cohort Equation and a modified Pooled Cohort Equation that included estimated glomerular filtrate rate. The Chronic Renal Insufficiency Cohort internal validation set demonstrated annualized receiver operating characteristic area under the curve values from 1 to 10 years ranging between 0.84 and 0.89 for the protein and 0.70 and 0.73 for the clinical models. Similar findings were observed in the Atherosclerosis Risk in Communities validation cohort. For nearly half of the individual proteins independently associated with cardiovascular risk, Mendelian randomization suggested a causal link to cardiovascular events or risk factors. Pathway analyses revealed enrichment of proteins involved in immunologic function, vascular and neuronal development, and hepatic fibrosis. CONCLUSION: In two sizeable populations with CKD, a proteomic risk model for incident cardiovascular disease surpassed clinical risk models recommended in clinical practice, even after including estimated glomerular filtration rate. New biological insights may prioritize the development of therapeutic strategies for cardiovascular risk reduction in the CKD population.

Does multi-way, long-range chromatin contact data advance 3D genome reconstruction?

BACKGROUND: Methods for inferring the three-dimensional (3D) configuration of chromatin from conformation capture assays that provide strictly pairwise interactions, notably Hi-C, utilize the attendant contact matrix as input. More recent assays, in particular split-pool recognition of interactions by tag extension (SPRITE), capture multi-way interactions instead of solely pairwise contacts. These assays yield contacts that straddle appreciably greater genomic distances than Hi-C, in addition to instances of exceptionally high-order chromatin interaction. Such attributes are anticipated to be consequential with respect to 3D genome reconstruction, a task yet to be undertaken with multi-way contact data. However, performing such 3D reconstruction using distance-based reconstruction techniques requires framing multi-way contacts as (pairwise) distances. Comparing approaches for so doing, and assessing the resultant impact of long-range and multi-way contacts, are the objectives of this study. RESULTS: We obtained 3D reconstructions via multi-dimensional scaling under a variety of weighting schemes for mapping SPRITE multi-way contacts to pairwise distances. Resultant configurations were compared following Procrustes alignment and relationships were assessed between associated Procrustes root mean square errors and key features such as the extent of multi-way and/or long-range contacts. We found that these features had surprisingly limited influence on 3D reconstruction, a finding we attribute to their influence being diminished by the preponderance of pairwise contacts. CONCLUSION: Distance-based 3D genome reconstruction using SPRITE multi-way contact data is not appreciably affected by the weighting scheme used to convert multi-way interactions to pairwise distances.

Kidney tubular epithelial cell ferroptosis links glomerular injury to tubulointerstitial pathology in lupus nephritis.

Ferroptosis is a druggable, iron-dependent form of cell death that is characterized by lipid peroxidation but has received little attention in lupus nephritis. Kidneys of lupus nephritis patients and mice showed increased lipid peroxidation mainly in the tubular segments and an increase in Acyl-CoA synthetase long-chain family member 4, a pro-ferroptosis enzyme. Nephritic mice had an attenuated expression of SLC7A11, a cystine importer, an impaired glutathione synthesis pathway, and low expression of glutathione peroxidase 4, a ferroptosis inhibitor. Lipidomics of nephritic kidneys confirmed ferroptosis. Using nephrotoxic serum, we induced immune complex glomerulonephritis in congenic mice and demonstrate that impaired iron sequestration within the proximal tubules exacerbates ferroptosis. Lupus nephritis patient serum rendered human proximal tubular cells susceptibility to ferroptosis which was inhibited by Liproxstatin-2, a novel ferroptosis inhibitor. Collectively, our findings identify intra-renal ferroptosis as a pathological feature and contributor to tubular injury in human and murine lupus nephritis.

Principal curve approaches for inferring 3D chromatin architecture.

Three-dimensional (3D) genome spatial organization is critical for numerous cellular processes, including transcription, while certain conformation-driven structural alterations are frequently oncogenic. Genome architecture had been notoriously difficult to elucidate, but the advent of the suite of chromatin conformation capture assays, notably Hi-C, has transformed understanding of chromatin structure and provided downstream biological insights. Although many findings have flowed from direct analysis of the pairwise proximity data produced by these assays, there is added value in generating corresponding 3D reconstructions deriving from superposing genomic features on the reconstruction. Accordingly, many methods for inferring 3D architecture from proximity data have been advanced. However, none of these approaches exploit the fact that single chromosome solutions constitute a one-dimensional (1D) curve in 3D. Rather, this aspect has either been addressed by imposition of constraints, which is both computationally burdensome and cell type specific, or ignored with contiguity imposed after the fact. Here, we target finding a 1D curve by extending principal curve methodology to the metric scaling problem. We illustrate how this approach yields a sequence of candidate solutions, indexed by an underlying smoothness or degrees-of-freedom parameter, and propose methods for selection from this sequence. We apply the methodology to Hi-C data obtained on IMR90 cells and so are positioned to evaluate reconstruction accuracy by referencing orthogonal imaging data. The results indicate the utility and reproducibility of our principal curve approach in the face of underlying structural variation.

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.

Early Biomarker Signatures in Surgical Sepsis.

INTRODUCTION: Sepsis has complex, time-sensitive pathophysiology and important phenotypic subgroups. The objective of this study was to use machine learning analyses of blood and urine biomarker profiles to elucidate the pathophysiologic signatures of subgroups of surgical sepsis patients. METHODS: This prospective cohort study included 243 surgical sepsis patients admitted to a quaternary care center between January 2015 and June 2017. We applied hierarchical clustering to clinical variables and 42 blood and urine biomarkers to identify phenotypic subgroups in a development cohort. Clinical characteristics and short-term and long-term outcomes were compared between clusters. A naïve Bayes classifier predicted cluster labels in a validation cohort. RESULTS: The development cohort contained one cluster characterized by early organ dysfunction (cluster I, n = 18) and one cluster characterized by recovery (cluster II, n = 139). Cluster I was associated with higher Acute Physiologic Assessment and Chronic Health Evaluation II (30 versus 16, P < 0.001) and SOFA scores (13 versus 5, P < 0.001), greater prevalence of chronic cardiovascular and renal disease (P < 0.001) and septic shock (78% versus 17%, P < 0.001). Cluster I had higher mortality within 14 d of sepsis onset (11% versus 1.5%, P = 0.001) and within 1 y (44% versus 20%, P = 0.032), and higher incidence of chronic critical illness (61% versus 30%, P = 0.001). The Bayes classifier achieved 95% accuracy and identified two clusters that were similar to development cohort clusters. CONCLUSIONS: Machine learning analyses of clinical and biomarker variables identified an early organ dysfunction sepsis phenotype characterized by inflammation, renal dysfunction, endotheliopathy, and immunosuppression, as well as poor short-term and long-term clinical outcomes.

Indoor Air Pollution and Susceptibility to Tuberculosis Infection in Urban Vietnamese Children.

Rationale: The Southeast Asian tuberculosis burden is high, and it remains unclear if urban indoor air pollution in this setting is exacerbating the epidemic. Objectives: To determine the associations of latent tuberculosis with common urban indoor air pollution sources (secondhand smoke, indoor motorcycle emissions, and cooking) in Southeast Asia. Methods: We enrolled child household contacts of patients with microbiologically confirmed active tuberculosis in Vietnam, from July 2017 to December 2019. We tested children for latent tuberculosis and evaluated air pollution exposures with questionnaires and personal aerosol sampling. We tested hypotheses using generalized estimating equations. Measurements and Main Results: We enrolled 72 patients with tuberculosis (27% with cavitary disease) and 109 of their child household contacts. Latent tuberculosis was diagnosed in 58 (53%) household contacts at baseline visit. Children experienced a 2.56-fold increased odds of latent tuberculosis for each additional household member who smoked (95% confidence interval, 1.27-5.16). Odds were highest among children exposed to indoor smokers and children <5 years old exposed to household smokers. Each residential floor above street-level pollution decreased the odds of latent tuberculosis by 36% (adjusted odds ratio, 0.64; 95% confidence interval, 0.42-0.96). Motorcycles parked inside children's homes and cooking with liquid petroleum gas compared with electricity increased the odds of latent tuberculosis, whereas kitchen ventilation decreased the effect, but these findings were not statistically significant. Conclusions: Common urban indoor air pollution sources were associated with increased odds of latent tuberculosis infection in child household contacts of patients with active tuberculosis.

Longitudinal Assessment of Body Composition and Its Association With Survival Among Participants of the ACTIVE/ADIPOSE Study.

OBJECTIVES: The importance of muscle wasting as a predictor of mortality in the hemodialysis population is not clear. Lack of association of muscle mass with survival in some studies could be related to reliance on single measures or to incorporation of excess extracellular water (ECW) into estimates of muscle mass. We examined changes in body composition over a 2-year period and the association of body composition with survival. DESIGN AND METHODS: We analyzed data from 325 adults receiving hemodialysis in the Bay Area. We estimated ECW, intracellular water (ICW), and fat mass by whole-body bioimpedance spectroscopy (BIS) at 0, 12, and 24 months from enrollment. We used linear mixed modeling to examine changes in body mass index and BIS-derived estimates of body composition and Cox modeling with BIS-derived estimates as time-varying independent variables to examine associations between body composition and survival in multivariable analyses. RESULTS: Body mass index declined over time. Considering individual components of body composition, ICW declined (-0.09 kg/m2 per year, 95% confidence interval -0.14 to -0.04), but fat mass and ECW did not change significantly. There were 120 deaths over a median of 5.2 years. The relationship between ICW and mortality was not linear such that the association was steeper at low values of ICW, whereas higher ICW was associated with better survival that was relatively stable above 9 kg/m2. Higher ECW was associated with higher mortality, and fat mass was not associated with survival. These associations were independent of markers of inflammation and nutritional status. CONCLUSIONS: ICW declined over 2 years in this cohort, whereas fat mass and ECW remained relatively stable. Higher ICW was associated with better survival, but higher fat mass was not. Higher ECW was associated with worse survival. These results suggest that muscle mass may predict survival among patients on hemodialysis.

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 (PRLN; spontaneous pregnancies); 0 CL without circulating RLN (programmed cycles); >1 CL with elevated PRLN (ovarian stimulation). Major findings were that declines in plasma osmolality (Posm) 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 PRLN; gestational declines in plasma uric acid (UA) concentration (PUA) were attenuated after IVF, especially programmed cycles, partly because of subdued increases of renal UA clearance; and PRLN 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, PRLN and plasma sFLT1 (PsFLT1) were directly correlated. Although PsFLT1 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 Posm and [Formula: see text]; 2) PRLN and CO were inversely correlated during early gestation, suggesting that PRLN in the lower range may have contributed to systemic vasodilation, whereas at higher PRLN 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.

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.

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.

Correlates and Consequences of High Serum Irisin Concentration in Patients on Hemodialysis: A Longitudinal Analysis.

OBJECTIVE: Irisin is a hormone released by muscle in response to exercise that acts on white adipose cells to stimulate browning of adipose tissue. We aimed to examine irisin correlates and consequences of irisin in patients receiving hemodialysis. DESIGN AND METHODS: A prospective cohort study was conducted using data from 749 prevalent patients receiving hemodialysis. Multivariable linear regression and multivariable generalized estimating equations were used to determine correlates of baseline and change in serum irisin concentration. Proportional hazards (Cox) regression was used to assess the association between serum irisin concentration and time to death. RESULTS: Age and body mass index were inversely associated with baseline and change in serum irisin concentration. Lower muscle mass as estimated by serum creatinine concentration was associated with lower irisin concentration (-1.38% per mg/dL (95% confidence interval [CI]: -2.45, -0.21) and with a 0.72% decrease in irisin concentration (95% CI: -1.48, -0.04) from baseline to 12 months. Each 50% higher serum interleukin-6 (IL-6) concentration was associated with 1.52% higher serum irisin concentration (95% CI: 0.38, 2.66) at baseline and an increase of 1.04% in irisin concentration over 1 year (95% CI: 0.47, 1.61). Irisin concentration at baseline was associated with higher hazard of death (hazards ratio: 1.45, 95% CI: 1.05 2.00); an increase in irisin concentration over 1 year was associated with a higher hazard of death (hazards ratio: 1.34, 95% CI: 1.01, 1.79). In formal mediation analysis, serum IL-6 was a mediator in the association between serum irisin and mortality. CONCLUSIONS: Lower serum creatinine (reflecting lower muscle mass) and higher serum IL-6 were associated with higher serum irisin concentrations. Higher serum irisin concentrations were associated with higher mortality, which may be mediated by inflammation.

Assessing stationary distributions derived from chromatin contact maps.

BACKGROUND: The spatial configuration of chromosomes is essential to various cellular processes, notably gene regulation, while architecture related alterations, such as translocations and gene fusions, are often cancer drivers. Thus, eliciting chromatin conformation is important, yet challenging due to compaction, dynamics and scale. However, a variety of recent assays, in particular Hi-C, have generated new details of chromatin structure, spawning a number of novel biological findings. Many findings have resulted from analyses on the level of native contact data as generated by the assays. Alternatively, reconstruction based approaches often proceed by first converting contact frequencies into distances, then generating a three dimensional (3D) chromatin configuration that best recapitulates these distances. Subsequent analyses can enrich contact level analyses via superposition of genomic attributes on the reconstruction. But, such advantages depend on the accuracy of the reconstruction which, absent gold standards, is inherently difficult to assess. Attempts at accuracy evaluation have relied on simulation and/or FISH imaging that typically features a handful of low resolution probes. While newly advanced multiplexed FISH imaging offers possibilities for refined 3D reconstruction accuracy evaluation, availability of such data is limited due to assay complexity and the resolution thereof is appreciably lower than the reconstructions being assessed. Accordingly, there is demand for new methods of reconstruction accuracy appraisal. RESULTS: Here we explore the potential of recently proposed stationary distributions, hereafter StatDns, derived from Hi-C contact matrices, to serve as a basis for reconstruction accuracy assessment. Current usage of such StatDns has focussed on the identification of highly interactive regions (HIRs): computationally defined regions of the genome purportedly involved in numerous long-range intra-chromosomal contacts. Consistent identification of HIRs would be informative with respect to inferred 3D architecture since the corresponding regions of the reconstruction would have an elevated number of k nearest neighbors (kNNs). More generally, we anticipate a monotone decreasing relationship between StatDn values and kNN distances. After initially evaluating the reproducibility of StatDns across replicate Hi-C data sets, we use this implied StatDn - kNN relationship to gauge the utility of StatDns for reconstruction validation, making recourse to both real and simulated examples. CONCLUSIONS: Our analyses demonstrate that, as constructed, StatDns do not provide a suitable measure for assessing the accuracy of 3D genome reconstructions. Whether this is attributable to specific choices surrounding normalization in defining StatDns or to the logic underlying their very formulation remains to be determined.

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.

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, ß2-microglobulin (ß2m), 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 ß2m 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 ß2m (-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.

Predialysis fluid overload and gait speed: a repeated measures analysis among patients on chronic dialysis.

BACKGROUND: Slow gait speed is associated with hospitalization and death. We examined whether predialysis fluid overload contributes to gait speed impairment. METHODS: We measured predialysis gait speed at baseline and 12 and 24 months among 298 patients recruited in the A Cohort Study to Investigate the Value of Exercise in ESRD/Analyses Designed to Investigate the Paradox of Obesity and Survival in ESRD. We used multivariable linear mixed modeling to examine associations between patient data and gait speed. We then added either bioimpedance-estimated volume of predialysis fluid overload or volume of delivered ultrafiltration to ascertain whether fluid excess was associated with gait speed and its trajectory. We also tested whether fluid overload change with time was predictive of gait speeds. RESULTS: The mean baseline gait speed was 1.01 m/s and it declined by an average of 0.08 m/s/year. Older age, nonwhite race, Hispanic ethnicity, diabetes, recent fall, recent hospitalization, tobacco use and lower serum albumin were associated with slower gait speed. Each liter of predialysis fluid overload was associated with a 0.02 m/s slower gait speed [95% confidence interval (CI) 0.01-0.04, P = 0.008] and 0.05 m/s additional slowing per year (95% CI 0.03-0.06, P < 0.0001). Higher ultrafiltration volumes were associated with 0.07 m/s slower gait speed per 3% body weight removed (0.002-0.14, P = 0.045) but not with gait speed trajectory (P = 0.08). Patients who increased fluid overload walked 0.08 m/s slower compared with those who decreased fluid overload (95% CI 0.003-0.15, P = 0.04). CONCLUSIONS: Predialysis fluid overload was associated with slower gait speed and gait speed decline over time. Interventions that limit fluid overload may lead to improvements in physical performance.

Memory T Cell Proliferation before Hepatitis C Virus Therapy Predicts Antiviral Immune Responses and Treatment Success.

The contribution of the host immune system to the efficacy of new anti-hepatitis C virus (HCV) drugs is unclear. We undertook a longitudinal prospective study of 33 individuals with chronic HCV treated with combination pegylated IFN-α, ribavirin, and telaprevir/boceprevir. We characterized innate and adaptive immune cells to determine whether kinetics of the host response could predict sustained virologic response (SVR). We show that characteristics of the host immune system present before treatment were correlated with successful therapy. Augmentation of adaptive immune responses during therapy was more impressive among those achieving SVR. Most importantly, active memory T cell proliferation before therapy predicted SVR and was associated with the magnitude of the HCV-specific responses at week 12 after treatment start. After therapy initiation, the most important correlate of success was minimal monocyte activation, as predicted by previous in vitro work. In addition, subjects achieving SVR had increasing expression of the transcription factor T-bet, a driver of Th1 differentiation and cytotoxic effector cell maturation. These results show that host immune features present before treatment initiation predict SVR and eventual development of a higher frequency of functional virus-specific cells in blood. Such host characteristics may also be required for successful vaccine-mediated protection.

Improving Assessment of Drug Safety Through Proteomics: Early Detection and Mechanistic Characterization of the Unforeseen Harmful Effects of Torcetrapib.

BACKGROUND: Early detection of adverse effects of novel therapies and understanding of their mechanisms could improve the safety and efficiency of drug development. We have retrospectively applied large-scale proteomics to blood samples from ILLUMINATE (Investigation of Lipid Level Management to Understand its Impact in Atherosclerotic Events), a trial of torcetrapib (a cholesterol ester transfer protein inhibitor), that involved 15 067 participants at high cardiovascular risk. ILLUMINATE was terminated at a median of 550 days because of significant absolute increases of 1.2% in cardiovascular events and 0.4% in mortality with torcetrapib. The aims of our analysis were to determine whether a proteomic analysis might reveal biological mechanisms responsible for these harmful effects and whether harmful effects of torcetrapib could have been detected early in the ILLUMINATE trial with proteomics. METHODS: A nested case-control analysis of paired plasma samples at baseline and at 3 months was performed in 249 participants assigned to torcetrapib plus atorvastatin and 223 participants assigned to atorvastatin only. Within each treatment arm, cases with events were matched to controls 1:1. Main outcomes were a survey of 1129 proteins for discovery of biological pathways altered by torcetrapib and a 9-protein risk score validated to predict myocardial infarction, stroke, heart failure, or death. RESULTS: Plasma concentrations of 200 proteins changed significantly with torcetrapib. Their pathway analysis revealed unexpected and widespread changes in immune and inflammatory functions, as well as changes in endocrine systems, including in aldosterone function and glycemic control. At baseline, 9-protein risk scores were similar in the 2 treatment arms and higher in participants with subsequent events. At 3 months, the absolute 9-protein derived risk increased in the torcetrapib plus atorvastatin arm compared with the atorvastatin-only arm by 1.08% (P=0.0004). Thirty-seven proteins changed in the direction of increased risk of 49 proteins previously associated with cardiovascular and mortality risk. CONCLUSIONS: Heretofore unknown effects of torcetrapib were revealed in immune and inflammatory functions. A protein-based risk score predicted harm from torcetrapib within just 3 months. A protein-based risk assessment embedded within a large proteomic survey may prove to be useful in the evaluation of therapies to prevent harm to patients. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT00134264.