The role of the kidney in the systemic elimination of interleukin 6, platelet-derived growth factor and transforming growth factor beta.

Study Goal: The aim of the study was to assess the role of the kidney in systemic elimination of IL-6 and growth factors (PDGF, TGF-β) by comparison of their concentrations in renal arteries and veins, peripheral veins and urine.
Material and Methods: 30 brain-dead kidney donors were included in the study. Samples were obtained during the harvesting procedure. 10 healthy volunteers served as controls. A mathematical model of elimination of investigated proteins from systemic circulation was developed. The elimination ratio (ER) formula indicates the predominance of renal synthesis or degradation and also quantifies the renal uptake (UR) and renal pass (PR) of investigated proteins. Serum levels of investigated proteins were estimated using an immunoenzymatic method (ELISA).
Results: Renal IL-6 uptake ratio (UR) amounted to 6.6%, elimination ratio (ER) amounted to 6.4% and pass ratio (PR) amounted to 0.2%. PDGF ratios amounted to 5.1%, 5.0% and 0.1% and TGF-β ratios amounted to -9%, -9% and 0%, respectively.
Conclusions: The kidney takes part in the elimination of IL-6 and PDGF from systemic circulation. The kidney does not take part in the elimination of TGF-β.
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