Anna Lorenzin, Massimo de Cal, Natascha Perin, Niccolò Morisi, Alessandra Brendolan, Paolo Lentini, Monica Zanella, Claudio Ronco
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引用次数: 0
Abstract
Introduction: Enkephalins, endogenous opioid peptides, are involved in the regulation of renal function. One derived molecule, proenkephalin A, also known as penKid, has been demonstrated to be a reliable biomarker for kidney function and its plasma concentration correlates with measured glomerular filtration rate. penKid is used for prediction and diagnosis of AKI and need of renal replacement therapy (RRT). penKid has also been used to predict the successful weaning from RRT in patients with AKI. Whether the concentration of penKid is affected or not by RRT is a controversial point and there are no studies describing the kinetics of the molecule in such conditions. The low molecular weight (4.5 kDa) would imply free removal by the glomerulus and the dialysis membranes. During RRT, this reduction could not be detected in clinical practice due to the complex kinetics involving either low dialytic clearance or increased production in response to impaired kidney function. The aim of this study was to determine the sieving coefficient and the diffusive clearance of the penKid molecule in conditions of in vitro continuous veno-venous hemofiltration (CVVH) and continuous veno-venous hemodialysis (CVVHD), respectively, and also the penKid removal ratio in conditions of in vitro hemoadsorption (HA) using a synthetic microporous resin.
Methods: Blood spiked with a lyophilized penKid peptide solved in 20 mm dipotassium phosphate and 6 mm disodium EDTA [pH 8] to reach target concentrations is used as testing solution. In each experiment, the blood batch was adjusted at a volume of 1,000 mL, maintained at 37°, and continuously stirred. Samples were collected from blood, ultrafiltrate, and spent dialysate at different times during the experiments. Sieving, clearance, and removal ratio were calculated.
Results: Significant removal of penKid was observed in CVVH (sieving 1.04 ± 0.27), in CVVHD (clearance 23.08 ± 0.89), and in HA (removal ratio 76.1 ± 1% after 120 min).
Conclusion: penKid is effectively removed by extracorporeal therapies. In presence of anuria, penKid generation kinetics can be calculated based on extracorporeal removal and volume variation. In steady state conditions, declining values may be the result of an initial renal function recovery and may suggest discontinuation and successful liberation from RRT.
期刊介绍:
Practical information on hemodialysis, hemofiltration, peritoneal dialysis and apheresis is featured in this journal. Recognizing the critical importance of equipment and procedures, particular emphasis has been placed on reports, drawn from a wide range of fields, describing technical advances and improvements in methodology. Papers reflect the search for cost-effective solutions which increase not only patient survival but also patient comfort and disease improvement through prevention or correction of undesirable effects. Advances in vascular access and blood anticoagulation, problems associated with exposure of blood to foreign surfaces and acute-care nephrology, including continuous therapies, also receive attention. Nephrologists, internists, intensivists and hospital staff involved in dialysis, apheresis and immunoadsorption for acute and chronic solid organ failure will find this journal useful and informative. ''Blood Purification'' also serves as a platform for multidisciplinary experiences involving nephrologists, cardiologists and critical care physicians in order to expand the level of interaction between different disciplines and specialities.