Nephrology Laboratory: Projects

Biobank

The lab has a collection of biospecimen from CKD patients, hemodialysis and peritoneal dialysis patients for biomedical research purposes, containing:

  • Serum, plasma (Heparin and EDTA)
  •  Urine
  •  buffy coat

 Three consecutive samples were collected with an interval of 1 year in parallel to clinical parameters and information on events and outcome.

Services

Quality control dialysis fluids

The new developments in extracorporeal treatment of end-stage kidney disease has enforced focus on the purity of dialysis fluid. A major challenge of high-flux HD and hemodiafiltration relates to the necessity for ultrapure dialysis fluid and for sterile non-pyrogenic substitution fluid.

Our laboratory developed a cell-based assay, sensitive to all possible contaminants present in dialysis fluid. Adding this THP-1 (monocytic cell line) assay to the classical detection methods (bacterial and yeast culture, LAL-test) offers more guarantee for detecting all possible bacterial derivative at play in the induction of micro-inflammation in dialysis patients. This assay is available for QC of dialysis fluid of external dialysis centers.

→ Methods: THP-1 bioassay and IL-1β expression, Limulus Amebocyte Lysate (LAL)-test

 

Quantification of uremic toxins

Quantification of protein-bound uremic retention solutes (uric acid, hippuric acid, indoxyl sulfate, p-cresyl glucuronide, p-cresyl sulfate, indole-3-acetic acid, and 3-carboxy-4-methyl-5-propyl-2-furanpropionic acid) in biological fluids (plasma, urine, dialysate).

→ Methods: HPLC, UPLC

Uremic Toxin Research

Our research unit focuses on experimental and translational research related to uremic toxicity in patients with Chronic kidney disease (CKD).

This disease is characterised by the accumulation of uremic retention compounds and a disruption of the intestinal barrier function contributing to chronic micro-inflammation and an increased risk for cardiovascular disease (CVD), the major cause of death in CKD patients.

Numerous pathophysiological effects of uremic retention compounds on different cell types (renal and cardio-vascular) have been demonstrated over the past decade, hence the name "uremic toxins".

 

Gut-kidney axis

Several of these uremic toxins originate from microbiota in the colon and are very difficult to remove by dialysis therapy. The ultimate goal of this research project is to develop therapeutical measures to alter the intestinal generation of uremic toxins, resulting in lowering their circulating levels, aiming at decreasing inflammation and cardiovascular morbidity and mortality in CKD patients.

 

Evaluation of biological activity

Our laboratory has been involved in the standardized screening of uremic retention solutes:

  • In vitro incubation assays with leukocytes, platelets and endothelial cells; evaluating surface markers, intra-cellular markers, apoptosis, proliferation, ROS production, viability, protein expression

Methods: flow cytometry, ELISA

  • In vivo rat model under infusion of uremic toxins; evaluating leukocyte recruitment, vascular leakage

Method: Intravital Microscopy

Our panel of assessment tests is part of the research performed in the context of uremic toxicity by the members of the European Uremic Toxin (EUTox) Workgroup involving 27 European Research Institutes involving renowned clinicians from large clinical centres, leading clinical and basic scientists, working on uremic toxicity.

This approach results in a classification of the uremic retention solutes according to their relative importance, indicating the uremic solutes of which circulating concentrations should be kept low by e.g. adapting the patients diet, applying a more selective dialysis, using specific adsorbance systems, …

 

Protein binding

Several uremic toxins are bound to proteins which makes them hard to be removed during hemodialysis. In order to optimise dialyser removal of protein-bound toxins, an in depth understanding is needed about their binding and about protein characteristics. Our lab has expertise in tests with healthy as well as uremic serum doing equilibrium dialysis and ultrafiltration techniques to unravel binding coefficients and binding competition between different toxins.

PKD Research

Exploration of lymphopenia in polycystic kidney disease

Hereditary polycystosis is a common hereditary renal disease with extra-renal manifestations including aneurysm formation, colonic diverticula, skin tumours and bronchiectasis. We recently demonstrated that lymphopenia is an inherent trait of this multisystemic disorder. Our lab explores the characteristics of isolated lymphocytes of patients with hereditary polycystosis and aims at unraveling mechanisms of abnormal proliferation or apoptosis.