Neutrophil Activation and Neutrophil Extracellular Trap Formation in Dialysis Patients.

Rationale & Objective: The removal of metabolic waste by passing blood through synthetic tubing and membranes generates an immune response, even with the most biocompatible materials available. We evaluated blood levels of neutrophil activation and cell death during dialysis to devise a set of markers by which future dialysis interventions might be measured for biocompatibility.

Study Design: Observational, case control.

Human Organ-Specific Endothelial Cell Heterogeneity.

The endothelium first forms in the blood islands in the extra-embryonic yolk sac and then throughout the embryo to establish circulatory networks that further acquire organ-specific properties during development to support diverse organ functions. Here, we investigated the properties of endothelial cells (ECs), isolated from four human major organs-the heart, lung, liver, and kidneys-in individual fetal tissues at three months' gestation, at gene expression, and at cellular function levels. We showed that organ-specific ECs have distinct expression patterns of gene clusters, which support their specific organ development and functions.

Identification and Quantitation of Leukocyte Populations in Human Kidney Tissue by Multi-parameter Flow Cytometry.

Inflammatory immune cells play direct pathological roles in cases of acute kidney injury (AKI) and chronic kidney disease (CKD). However, the identification and characterization of distinct populations of leukocytes in human kidney biopsies have been confounded by the limitations of immunohistochemical (IHC)-based techniques used to detect them. This methodology is not amenable to the combinations of multiple markers necessary to unequivocally define discrete immune cell populations.

Multicolor Flow Cytometry and Cytokine Analysis Provides Enhanced Information on Kidney Transplant Biopsies.

Introduction: Current processing of renal biopsy samples provides limited information about immune mechanisms causing kidney injury and disease activity. We used flow cytometry with transplanted kidney biopsy samples to provide more information on the immune status of the kidney.

Methods: To enhance the information available from a biopsy, we developed a technique for reducing a fraction of a renal biopsy sample to single cells for multicolor flow cytometry and quantitation of secreted cytokines present within the biopsy sample.

Plasma C4d+ Endothelial Microvesicles Increase in Acute Antibody-Mediated Rejection.

Background: Antibody-mediated rejection (AMR) is a major cause of kidney allograft loss. Currently, AMR diagnosis relies on biopsy which is an invasive procedure. A noninvasive biomarker of acute AMR could lead to early diagnosis and treatment of this condition and improve allograft outcome.

Development of a microphysiological model of human kidney proximal tubule function.

The kidney proximal tubule is the primary site in the nephron for excretion of waste products through a combination of active uptake and secretory processes and is also a primary target of drug-induced nephrotoxicity. Here, we describe the development and functional characterization of a 3-dimensional flow-directed human kidney proximal tubule microphysiological system. The system replicates the polarity of the proximal tubule, expresses appropriate marker proteins, exhibits biochemical and synthetic activities, as well as secretory and reabsorptive processes associated with proximal tubule function in vivo.

A Novel Three-Dimensional Human Peritubular Microvascular System.

Human kidney peritubular capillaries are particularly susceptible to injury, resulting in dysregulated angiogenesis, capillary rarefaction and regression, and progressive loss of kidney function. However, little is known about the structure and function of human kidney microvasculature. Here, we isolated, purified, and characterized human kidney peritubular microvascular endothelial cells (HKMECs) and reconstituted a three-dimensional human kidney microvasculature in a flow-directed microphysiologic system.

CMS-required visits adversely impact Seattle area hemodialysis program.

Chronic hemodialysis in Seattle developed with a highly patient-centric approach, providing patients the option of dialyzing in neighborhood units under the administration of a non-profit organization, the Northwest Kidney Center (NKC). This study examined the effects of a requirement in the 2009 Conditions for Coverage that in-center hemodialysis patients be visited quarterly during their treatment session. A retrospective analysis of quality outcome indicators for patients managed at the University of Washington Medical Center and dialyzing at NKC in 2008 and 2010 found that dialysis adequacy (eKt/V), phosphorus, albumin, and hemoglobin were not improved by quarterly dialysis visits.

Innovations in preclinical biology: ex vivo engineering of a human kidney tissue microperfusion system.

Kidney disease is a public health problem that affects more than 20 million people in the US adult population, yet little is understood about the impact of kidney disease on drug disposition. Consequently there is a critical need to be able to model the human kidney and other organ systems, to improve our understanding of drug efficacy, safety, and toxicity, especially during drug development. The kidneys in general, and the proximal tubule specifically, play a central role in the elimination of xenobiotics.

Increased tubulointerstitial recruitment of human CD141(hi) CLEC9A(+) and CD1c(+) myeloid dendritic cell subsets in renal fibrosis and chronic kidney disease.

Dendritic cells (DCs) play critical roles in immune-mediated kidney diseases. Little is known, however, about DC subsets in human chronic kidney disease, with previous studies restricted to a limited set of pathologies and to using immunohistochemical methods. In this study, we developed novel protocols for extracting renal DC subsets from diseased human kidneys and identified, enumerated, and phenotyped them by multicolor flow cytometry.

Treatment of severe lactic acidosis during the pre-anhepatic stage of liver transplant surgery with intraoperative hemodialysis.

Severe uncompensated lactic acidosis manifesting during the pre-anhepatic stage of orthotopic liver transplant surgery is an uncommon event, but it poses serious concern because of the additional lactate production and impaired elimination by the liver that develops during the anhepatic and allograft reperfusion stages of the procedure. A man with end-stage liver disease secondary to hepatitis C and hemochromatosis and normal renal function, who developed severe lactic acidosis in the pre-anhepatic stage of liver transplantation, was treated successfully with intraoperative, continuous venovenous hemodialysis. Hemodialysis effectively corrected the patient's lactic acidosis and removed lactate, which contributed to hemodynamic stability during the anhepatic and graft reperfusion stages of his liver transplant surgery.

Proliferative potential of human kidney endothelial cells: bone marrow-derived cells may not be required for high proliferation.

Background: Proliferative potential of a single cell, defined as the number of progeny it gives rise to, has been used to define a hierarchy of endothelial progenitor cells in blood. Cells with high proliferative potential are presumed to have greater capacity for endothelium repair. Based on results with commercially available endothelial cells, it has been proposed that a proliferative hierarchy of endothelial cells also exists within blood vessels.

Higher levels of leflunomide are associated with hemolysis and are not superior to lower levels for BK virus clearance in renal transplant patients.

Background And Objectives: Leflunomide use in renal transplantation has been increasing. Outcome correlation and safety data are still to be refined. The goals of this study were to report one center's experience with leflunomide, specifically the correlation of leflunomide levels with the outcomes of BK nephropathy and the observed toxic effects during the treatment with leflunomide.

Normal human kidney HLA-DR-expressing renal microvascular endothelial cells: characterization, isolation, and regulation of MHC class II expression.

Human, but not murine, renal peritubular and glomerular capillaries constitutively express class II major histocompatibility (MHC) proteins at high levels in normal human kidney. Expression of class II proteins on renal microvascular endothelial cells (RMEC) makes it available to circulating lymphocytes and imparts a surveillance capacity to RMEC for controlling inflammatory responses. In this report, the co-expression of HLA-DR and the endothelial marker CD31 are used to identify RMEC as a distinct population of cells within a standard renal biopsy using flow cytometry.