Development and Validation of a New Hierarchical Composite End Point for Clinical Trials of Kidney Disease Progression.

Significance Statement: The established composite kidney end point in clinical trials combines clinical events with sustained large changes in GFR but does not weigh the relative clinical importance of the end point components. By contrast, a hierarchical composite end point (HCE) accounts for the clinical importance of the end point components. The authors developed and validated a kidney HCE that combines clinical kidney outcomes with longitudinal GFR changes (GFR slope).

Validity and Utility of a Hierarchical Composite End Point for Clinical Trials of Kidney Disease Progression: A Review.

Clinical trials in nephrology often use composite end points comprising clinical events, such as onset of ESKD and initiation of kidney function replacement therapy, along with a sustained large ( e.g. , ≥50%) decrease in GFR.

Perioperative THR-184 and AKI after Cardiac Surgery.

AKI after cardiac surgery is associated with mortality, prolonged hospital length of stay, use of dialysis, and subsequent CKD. We evaluated the effects of THR-184, a bone morphogenetic protein-7 agonist, in patients at high risk for AKI after cardiac surgery. We conducted a randomized, double-blind, placebo-controlled, multidose comparison of the safety and efficacy of perioperative THR-184 using a two-stage seamless adaptive design in 452 patients between 18 and 85 years of age who were scheduled for nonemergent cardiac surgery requiring cardiopulmonary bypass and had recognized risk factors for AKI.

The establishment and validation of novel therapeutic targets to retard progression of chronic kidney disease.

The focus of this article is to define goals and resulting action plans that can be collectively embraced by interested stakeholders to facilitate new therapeutic approaches to mitigate chronic kidney disease progression. The specific goals include identifying druggable targets, increasing the capacity for preclinical and early clinical development, broadening the availability of new therapeutic approaches, and increasing investment in the development of new therapies to limit chronic kidney disease. Key deliverables include the establishment of new regional, national, and global consortia; development of clinical trial networks; and creation of programs to support the temporary mutual movement of scientists between academia and the biotechnology and pharmaceutical sector.

Genetic and environmental risk factors for chronic kidney disease.

In order to change the current state of chronic kidney disease knowledge and therapeutics, a fundamental improvement in the understanding of genetic and environmental causes of chronic kidney disease is essential. This article first provides an overview of the existing knowledge gaps in our understanding of the genetic and environmental causes of chronic kidney disease, as well as their interactions. The second part of the article formulates goals that should be achieved in order to close these gaps, along with suggested timelines and stakeholders that are to be involved.

Evaluation of dilution and normalization strategies to correct for urinary output in HPLC-HRTOFMS metabolomics.

Reliable identification of features distinguishing biological groups of interest in urinary metabolite fingerprints requires the control of total metabolite abundance, which may vary significantly as the kidneys adjust the excretion of water and solutes to meet the homeostatic needs of the body. Failure to account for such variation may lead to misclassification and accumulation of missing data in case of less concentrated urine specimens. Here, different pre- and post-acquisition methods of normalization were compared systematically for their ability to recover features from liquid chromatography-mass spectrometry metabolite fingerprints of urine that allow distinction between patients with chronic kidney disease and healthy controls.

Retinopathy and clinical outcomes in patients with type 2 diabetes mellitus, chronic kidney disease, and anemia.

Objective: Retinopathy is an established microvascular complication of type 2 diabetes mellitus (T2DM), but its independent relationship with macrovascular and other microvascular complications is less well defined across the spectrum of kidney disease in T2DM. We examined the prognostic value of retinopathy in assessing the risk of developing end-stage renal disease (ESRD), cardiovascular morbidity or death among patients in the Trial to Reduce cardiovascular Events with Aranesp Therapy (TREAT).

Design: TREAT enrolled 4038 patients with T2DM, chronic kidney disease (CKD) and moderate anemia.

Glomerular filtration rate estimation using cystatin C alone or combined with creatinine as a confirmatory test.

Background: Glomerular filtration rate (GFR) estimating equations using the combination of creatinine and cystatin C (eGFRcr-cys) are more accurate than equations using either alone (eGFRcr or eGFRcys). New guidelines suggest measuring cystatin C as a confirmatory test when eGFRcr may be inaccurate, but do not specify demographic or clinical conditions in which eGFRcys or eGFRcr-cys are more accurate than eGFRcr nor which estimate to use in such circumstances.

Methods: We compared the performance of the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations in 1119 subjects in the CKD-EPI cystatin C external validation dataset.

Red blood cell transfusions and the risk of allosensitization in patients awaiting primary kidney transplantation.

Background: Most studies of HLA sensitization after red blood cell transfusion in transplant candidates were done before widespread use of leuko reduced blood and based on relatively insensitive, nonspecific antibody assays. We evaluated the effect of transfusion on the breadth and magnitude of HLA antibody formation using current, sensitive, HLA-specific immunoassays.

Methods: Serial HLA antibody data were merged with transfusion data from the US Renal Data System for 1324 patients on the kidney transplant wait list (2004-2010).

Risk of pure red cell aplasia in patients with hepatitis C receiving antiviral therapy and an erythropoiesis-stimulating agent.

Antibody-mediated pure red cell aplasia (PRCA) has been primarily observed in patients with chronic kidney disease treated with an erythropoiesis-stimulating agent (ESA); only a few anecdotal cases have been reported in other patient populations. We searched the Amgen Global Safety Adverse Event Database and identified 14 patients with hepatitis C who developed severe anemia, anti-erythropoietin antibodies, and bone marrow biopsy-proven PRCA, while receiving interferon therapy (with or without ribavirin) and an ESA. During the follow-up period and after ESA treatment stopped, 11 patients no longer required transfusions and 3 did.

Sensitization from transfusion in patients awaiting primary kidney transplant.

Background: Sensitization to human leukocyte antigen (HLA) from red blood cell (RBC) transfusion is poorly quantified and is based on outdated, insensitive methods. The objective was to evaluate the effect of transfusion on the breadth, magnitude and specificity of HLA antibody formation using sensitive and specific methods.

Methods: Transfusion, demographic and clinical data from the US Renal Data System were obtained for patients on dialysis awaiting primary kidney transplant who had ≥ 2 HLA antibody measurements using the Luminex single-antigen bead assay.

Hemoglobin stability in patients with anemia, CKD, and type 2 diabetes: an analysis of the TREAT (Trial to Reduce Cardiovascular Events With Aranesp Therapy) placebo arm.

Background: Sparse data are available about the natural history of hemoglobin (Hb) level trends in contemporary patients with anemia, chronic kidney disease (CKD), and type 2 diabetes mellitus. We intended to describe Hb level trends over time with no or minimal administration of erythropoiesis-stimulating agents.

Study Design: Prospective clinical trial cohort.

EGR1 and EGR2 involvement in vertebrate tendon differentiation.

The molecules involved in vertebrate tendon formation during development remain largely unknown. To date, only two DNA-binding proteins have been identified as being involved in vertebrate tendon formation, the basic helix-loop-helix transcription factor Scleraxis and, recently, the Mohawk homeobox gene. We investigated the involvement of the early growth response transcription factors Egr1 and Egr2 in vertebrate tendon formation.

Erythropoietic response and outcomes in kidney disease and type 2 diabetes.

Background: Non–placebo-controlled trials of erythropoiesis-stimulating agents (ESAs) comparing lower and higher hemoglobin targets in patients with chronic kidney disease indicate that targeting of a lower hemoglobin range may avoid ESA-associated risks. However, target-based strategies are confounded by each patient's individual hematopoietic response.

Methods: We assessed the relationship among the initial hemoglobin response to darbepoetin alfa after two weight-based doses, the hemoglobin level achieved after 4 weeks, the subsequent darbepoetin alfa dose, and outcomes in 1872 patients with chronic kidney disease and type 2 diabetes mellitus who were not receiving dialysis.

Long-term evolution and determinants of renal function in HIV-infected patients who began receiving combination antiretroviral therapy in 1997-1999, ANRS CO8 APROCO-COPILOTE.

Among 1121 patients (90% Caucasian) infected by the human immunodeficiency virus (HIV), the glomerular filtration rate increased (+0.72 mL/min/1.73 m(2)/month) from treatment initiation to month 16 (the rate increase was lower among men and those with low body mass index, AIDS, or receipt of indinavir), then remained stable up to 7 years.

A peptide-based erythropoietin-receptor agonist for pure red-cell aplasia.

Background: We investigated whether a novel, synthetic, peptide-based erythropoietin-receptor agonist (Hematide, Affymax) can stimulate erythropoiesis in patients with anemia that is caused by antierythropoietin antibodies.

Methods: In this open-label, single-group trial, we enrolled patients with chronic kidney disease who had pure red-cell aplasia or hypoplasia due to antierythropoietin antibodies and treated them with a synthetic peptide-based erythropoietin-receptor agonist. The agonist was administered by subcutaneous injection at an initial dose of 0.

Timing of onset of CKD-related metabolic complications.

Chronic kidney disease (CKD) guidelines recommend evaluating patients with GFR <60 ml/min per 1.73 m(2) for complications, but little evidence supports the use of a single GFR threshold for all metabolic disorders. We used data from the NephroTest cohort, including 1038 adult patients who had stages 2 through 5 CKD and were not on dialysis, to study the occurrence of metabolic complications.

Epoetin-associated pure red cell aplasia: past, present, and future considerations.

Background: Since 1988, millions of patients have received epoetin products intravenously (IV) and subcutaneously. In 1998, epoetin-associated pure red cell aplasia (PRCA) was first reported and causation was attributed to formulations without human serum albumin (HSA), subcutaneous administration, and uncoated rubber stoppers.

Study Design And Methods: Data on erythropoietin (EPO)-associated PRCA were obtained from the Food and Drug Administration (FDA), regulatory authorities in other countries, and the manufacturers of epoetin alfa, epoetin beta, and darbepoetin.

Pitfalls of measuring total blood calcium in patients with CKD.

Disorders of mineral and bone metabolism are prevalent in patients with chronic kidney disease (CKD). The recent National Kidney Foundation Kidney Disease Outcomes Quality Initiative (K/DOQI) guidelines recommend that blood calcium (Ca) be regularly measured in patients with stages 3 to 5 CKD. The Kidney Disease: Improving Global Outcomes (KDIGO) position states that the measurement of ionized Ca (iCa) is preferred and that if total Ca (tCa) concentration is used instead, then it should be adjusted in the setting of hypoalbuminemia.

Estimating GFR using serum cystatin C alone and in combination with serum creatinine: a pooled analysis of 3,418 individuals with CKD.

Background: Serum cystatin C was proposed as a potential replacement for serum creatinine in glomerular filtration rate (GFR) estimation. We report the development and evaluation of GFR-estimating equations using serum cystatin C alone and serum cystatin C, serum creatinine, or both with demographic variables.

Study Design: Test of diagnostic accuracy.

Primary glomerulonephritis: an update on renal survival and determinants of progression.

Background: Few epidemiological studies have investigated the long-term outcome of primary glomerulonephritis (GN) and its determinants in the decade since angiotensin-converting enzyme inhibitors entered widespread use.

Aim: To study several traditional and less traditional risk factors for kidney disease progression in a cohort of patients with primary GN.

Design: Retrospective cohort study.

Pure red cell aplasia induced by erythropoiesis-stimulating agents.

Pure red cell aplasia in patients who are treated for anemia of chronic kidney disease with erythropoiesis-stimulating agents such as epoetin was first reported in 1998. Although the incidence of pure red cell aplasia peaked in 2002, it remains important for nephrologists to know how to investigate a suspected case of pure red cell aplasia and how to identify other causes of hyporesponsiveness to erythropoiesis-stimulating agents, which account for the vast majority of such cases. The authors reviewed the current status of information in the literature and drew on their personal experiences with patients regarding the diagnosis and management of epoetin-induced pure red cell aplasia.

Vasculitides associated with malignancies: analysis of sixty patients.

Objective: To describe characteristics and outcomes of vasculitides associated with malignancies.

Methods: The requirement for inclusion in this retrospective, 10-year study was development of vasculitis in patients with a progressing malignancy. Malignancies secondary to immunosuppressants used to treat vasculitis were excluded.