Urine Cell Transcriptomes Implicate Specific Renal Inflammatory Pathways Associated With Difficult-to-Control Hypertension.

Background The renal mechanisms involved in the maintenance of human hypertension and resistance to treatment are not well understood. Animal studies suggest that chronic renal inflammation contributes to hypertension. We studied cells shed in first-morning urine samples from individuals who were hypertensive who exhibited difficult-to-control blood pressure (BP). We performed bulk RNA sequencing of these shed cells to develop transcriptome-wide associations with BP. We also analyzed nephron-specific genes and used an unbiased bioinformatic approach to find signaling pathways activated in difficult-to-control hypertension. Methods and Results Participants who completed the SPRINT (Systolic Blood Pressure Intervention Trial) at a single trial site were recruited, and cells shed in first-morning urine samples collected. A total of 47 participants were divided into 2 groups based on hypertension control. The BP-difficult group (n=29) had systolic BP>140 mm Hg, >120 mm Hg after intensive treatment for hypertension, or required more than the median number of antihypertensive drugs used in SPRINT. The easy-to-control BP group (n=18) comprised the remainder of the participants. A total of 60 differentially expressed genes were identified with a >2-fold change in the BP-difficult group. In BP-difficult participants, 2 of the most upregulated genes were associated with inflammation: Tumor Necrosis Factor Alpha Induced Protien 6 (fold change, 7.76; P=0.006) and Serpin Family B Member 9 (fold change, 5.10; P=0.007). Biological pathway analysis revealed an overrepresentation of inflammatory networks, including interferon signaling, granulocyte adhesion and diapedesis, and Janus Kinase family kinases in the BP-difficult group (P<0.001). Conclusions We conclude that transcriptomes from cells shed in first-morning urine identify a gene expression profile in difficult-to-control hypertension that associates with renal inflammation.

Pharmacological effects of ex vivo mesenchymal stem cell immunotherapy in patients with acute kidney injury and underlying systemic inflammation.

Mesenchymal stem cells (MSCs) have natural immunoregulatory functions that have been explored for medicinal use as a cell therapy with limited success. A phase Ib study was conducted to evaluate the safety and immunoregulatory mechanism of action of MSCs using a novel ex vivo product (SBI-101) to preserve cell activity in patients with severe acute kidney injury. Pharmacological data demonstrated MSC-secreted factor activity that was associated with anti-inflammatory signatures in the molecular and cellular profiling of patient blood. Systems biology analysis captured multicompartment effects consistent with immune reprogramming and kidney tissue repair. Although the study was not powered for clinical efficacy, these results are supportive of the therapeutic hypothesis, namely, that treatment with SBI-101 elicits an immunotherapeutic response that triggers an accelerated phenotypic switch from tissue injury to tissue repair. Ex vivo administration of MSCs, with increased power of testing, is a potential new biological delivery paradigm that assures sustained MSC activity and immunomodulation.

High SARS-CoV-2 Viral Load in Urine Sediment Correlates with Acute Kidney Injury and Poor COVID-19 Outcome.

BACKGROUND: AKI is a complication of coronavirus disease 2019 (COVID-19) that is associated with high mortality. Despite documented kidney tropism of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), there are no consistent reports of viral detection in urine or correlation with AKI or COVID-19 severity. Here, we hypothesize that quantification of the viral load of SARS-CoV-2 in urine sediment from patients with COVID-19 correlates with occurrence of AKI and mortality. METHODS: The viral load of SARS-CoV-2 in urine sediments (U-viral load) was quantified by qRT-PCR in 52 patients with PCR-confirmed COVID-19 diagnosis, who were hospitalized between March 15 and June 8, 2020. Immunolabeling of SARS-CoV-2 proteins Spike and Nucleocapsid was performed in two COVID-19 kidney biopsy specimens and urine sediments. Viral infectivity assays were performed from 32 urine sediments. RESULTS: A total of 20 patients with COVID-19 (39%) had detectable SARS-CoV-2 U-viral load, of which 17 (85%) developed AKI with an average U-viral load four-times higher than patients with COVID-19 who did not have AKI. U-viral load was highest (7.7-fold) within 2 weeks after AKI diagnosis. A higher U-viral load correlated with mortality but not with albuminuria or AKI stage. SARS-CoV-2 proteins partially colocalized with the viral receptor ACE2 in kidney biopsy specimens in tubules and parietal cells, and in urine sediment cells. Infective SARS-CoV-2 was not detected in urine sediments. CONCLUSION: Our results further support SARS-CoV-2 kidney tropism. A higher SARS-CoV-2 viral load in urine sediments from patients with COVID-19 correlated with increased incidence of AKI and mortality. Urinary viral detection could inform the medical care of patients with COVID-19 and kidney injury to improve prognosis.

A pre-specified analysis of the DAPA-CKD trial demonstrates the effects of dapagliflozin on major adverse kidney events in patients with IgA nephropathy.

Immunoglobulin A (IgA) nephropathy is a common form of glomerulonephritis, which despite use of renin-angiotensin-aldosterone-system blockers and immunosuppressants, often progresses to kidney failure. In the Dapagliflozin and Prevention of Adverse Outcomes in Chronic Kidney Disease trial, dapagliflozin reduced the risk of kidney failure and prolonged survival in participants with chronic kidney disease with and without type 2 diabetes, including those with IgA nephropathy. Participants with estimated glomerular filtration rate (eGFR) 25-75 mL/min/1.73m2 and urinary albumin-to-creatinine ratio 200-5000 mg/g (22.6-565 mg/mol) were randomized to dapagliflozin 10mg or placebo, as adjunct to standard care. The primary composite endpoint was a sustained decline in eGFR of 50% or more, end-stage kidney disease, or death from a kidney disease-related or cardiovascular cause. Of 270 participants with IgA nephropathy (254 [94%] confirmed by previous biopsy), 137 were randomized to dapagliflozin and 133 to placebo, and followed for median 2.1 years. Overall, mean age was 51.2 years; mean eGFR, 43.8 mL/min/1.73m2; and median urinary albumin-to-creatinine ratio, 900 mg/g. The primary outcome occurred in six (4%) participants on dapagliflozin and 20 (15%) on placebo (hazard ratio, 0.29; 95% confidence interval, 0.12, 0.73). Mean rates of eGFR decline with dapagliflozin and placebo were -3.5 and -4.7 mL/min/1.73m2/year, respectively. Dapagliflozin reduced the urinary albumin-to-creatinine ratio by 26% relative to placebo. Adverse events leading to study drug discontinuation were similar with dapagliflozin and placebo. There were fewer serious adverse events with dapagliflozin, and no new safety findings in this population. Thus, in participants with IgA nephropathy, dapagliflozin reduced the risk of chronic kidney disease progression with a favorable safety profile.

The safety of achieved iron stores and their effect on IV iron and ESA use: post-hoc results from a randomized trial of ferric citrate as a phosphate binder in dialysis
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Iron stores assuring optimal efficacy/safety for erythropoiesis are unknown in the dialysis population. Using multicenter trial data, we related safety profiles, erythropoiesis-stimulating agent (ESA), and intravenous iron dosing to achieved iron stores in 441 subjects randomized 2 : 1 to ferric citrate or active control as their phosphate binder over 52 weeks. Intravenous iron was given at each site's discretion if ferritin ≤ 1,000 ng/mL and transferrin saturation ≤ 30%. Multivariable time-dependent Cox regression jointly related the primary safety outcome (composite of cardiac, infection, gastrointestinal, and hepatobiliary serious adverse events) to moving averages of ferritin and transferrin saturation over the preceding 90 days with covariate adjustment. Multivariable generalized estimating equations related elevated ESA and intravenous iron doses to trailing 90-day averages of ferritin and transferrin saturation with covariate adjustment. The adjusted hazard ratio for the safety composite per 10% increase in transferrin saturation was 0.84 (95% confidence interval 0.68 - 1.02, p = 0.08) and 1.09 (0.86 - 1.35, p = 0.48) per 400 ng/mL increase in ferritin. The adjusted hazard ratio for the safety composite was 0.50 (0.29 - 0.88, p = 0.016) for the highest transferrin saturation tertile vs. the lowest. Adjusted odds ratios for higher intravenous iron dose were lower in the highest (0.23 [0.16 - 0.35], p < 0.001) and middle transferrin saturation tertile (0.42 [0.31 - 0.57], p < 0.001) vs. lowest. Incidence of elevated ESA dose was lower in the highest transferrin saturation tertile (p = 0.01). Ferritin did not predict clinical events or ESA dose. Transferrin saturation may be a better marker than serum ferritin to judge optimal iron stores in dialysis patients. Transferrin saturations > 34% are safe and provide maximal efficacy.
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Orthostatic changes in systolic blood pressure among SPRINT participants at baseline.

Orthostatic changes in systolic blood pressure (SBP) impact cardiovascular outcomes. In this study, we aimed to determine the pattern of orthostatic systolic pressure changes in participants enrolled in the SBP Intervention Trial (SPRINT) at their baseline visit before randomization and sought to understand clinical factors predictive of these changes. Of the 9323 participants enrolled in SPRINT, 8662 had complete data for these analyses. The SBP after 1 minute of standing was subtracted from the mean value of the three preceding seated SBP values. At the baseline visit, medical history, medications, anthropometric measures, and standard laboratory testing were undertaken. The mean age of SPRINT participants was 68 years, two-thirds were male, with 30% black, 11% Hispanic, and 55% Caucasian. The spectrum of SBP changes on standing demonstrated that increases in SBP were as common as declines, and about 5% of participants had an increase, and 5% had a decrease of >20 mm Hg in SBP upon standing. Female sex, taller height, more advanced kidney disease, current smoking, and several drug classes were associated with larger declines in BP upon standing, while black race, higher blood levels of glucose and sodium, and heavier weight were associated with more positive values of the change in BP upon standing. Our cross-sectional results show a significant spectrum of orthostatic SBP changes, reflecting known (eg, age) and less well-known (eg, kidney function) relationships that may be important considerations in determining the optimal target blood pressure in long-term outcomes of older hypertensive patients.

Ferric Citrate, an Iron-Based Phosphate Binder, Reduces Health Care Costs in Patients on Dialysis Based on Randomized Clinical Trial Data.

BACKGROUND: Patients with end-stage renal disease (ESRD) require phosphate binders for hyperphosphatemia and erythropoiesis-stimulating agents (ESAs) and intravenous (i.v.) iron for anemia. Ferric citrate (FC) is a novel, iron-based phosphate binder that increases iron stores and decreases i.v. iron and ESA usage while maintaining hemoglobin levels, and may decrease the cost of ESRD care. The study objectives were to (1) quantify differences in ESA and i.v. iron usage among ESRD patients receiving FC compared with active control (AC) (sevelamer carbonate and/or calcium acetate) on the basis of data from a 52-week phase III clinical trial and (2) standardize trial data to the general United States (US) ESRD population and calculate the potential impact of FC on ESRD cost/patient/year in the USA. STUDY DESIGN: The study was a randomized, controlled clinical trial. SETTING AND POPULATION: A total of 441 adult subjects with ESRD who received FC or AC for 52 weeks were included. MODEL, PERSPECTIVE, AND TIMELINE: Differences in ESA and i.v. iron usage between the treatment groups were modeled over time using generalized linear mixed models and zero-inflated Poisson models. Trends were modeled via logarithmic curves, and utilization patterns were applied to the general dialysis population to estimate expected resource savings. OUTCOMES: Study outcomes were costs saved/patient/year using FC versus AC (US dollars). RESULTS: Our model suggests an annual decrease of 129,106 U of ESAs and 1960 mg of i.v. iron per patient in the second year after a switch from AC to FC. Applying 2013 Medicare pricing, this would save $1585 in ESAs and $516 in i.v. iron: a total of $2101/patient/year; these savings would be expected to double for managed care plans. LIMITATIONS: The projections were made on 1 year of trial data. CONCLUSIONS: Phosphate binding with FC reduces i.v. iron and ESA usage. Given the high cost burden of ESRD, our model demonstrates significant potential cost savings. TRIAL REGISTRATION: ClinicalTrials.gov (NCT01191255) http://clinicaltrials.gov/ct2/show/NCT01191255 .

Ferric Citrate Reduces Intravenous Iron and Erythropoiesis-Stimulating Agent Use in ESRD.

Ferric citrate (FC) is a phosphate binder with shown efficacy and additional effects on iron stores and use of intravenous (iv) iron and erythropoiesis-stimulating agents (ESAs). We provide detailed analyses of changes in iron/hematologic parameters and iv iron/ESA use at time points throughout the active control period of a phase 3 international randomized clinical trial. In all, 441 subjects were randomized (292 to FC and 149 to sevelamer carbonate and/or calcium acetate [active control (AC)]) and followed for 52 weeks. Subjects on FC had increased ferritin and transferrin saturation (TSAT) levels compared with subjects on AC by week 12 (change in ferritin, 114.1±29.35 ng/ml; P<0.001; change in TSAT, 8.62%±1.57%; P<0.001). Change in TSAT plateaued at this point, whereas change in ferritin increased through week 24, remaining relatively stable thereafter. Subjects on FC needed less iv iron compared with subjects on AC over 52 weeks (median [interquartile range] dose=12.9 [1.0-28.9] versus 26.8 [13.4-47.6] mg/wk; P<0.001), and the percentage of subjects not requiring iv iron was higher with FC (P<0.001). Cumulative ESA over 52 weeks was lower with FC than AC (median [interquartile range] dose=5303 [2023-9695] versus 6954 [2664-12,375] units/wk; P=0.04). Overall, 90.3% of subjects on FC and 89.3% of subjects on AC experienced adverse events. In conclusion, treatment with FC as a phosphate binder results in increased iron parameters apparent after 12 weeks and reduces iv iron and ESA use while maintaining hemoglobin over 52 weeks, with a safety profile similar to that of available binders.

Optimizing blood pressure control in patients with nondiabetic glomerular disease.

Hypertension is a common problem among patients with glomerular disease and CKD. Optimal blood pressure targets for these patients have been the source of much debate. Careful review of the available data supports a blood pressure target of less than 140/90 mmHg. Consideration for a lower goal of less than 130/80 mmHg should be given for patients with heavy proteinuria. Renin-angiotensin system inhibitors should be used as the cornerstone of therapy for all patients with glomerular disease and CKD.