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Kidney and splanchnic handling of Interleukin-6 in humans

2007; Elsevier BV; Volume: 37; Issue: 1 Linguagem: Inglês

10.1016/j.cyto.2007.02.015

1096-0023

Giacomo Garibotto, Antonella Sofia, Manrico Balbi, Vanessa Procopio, Barbara Villaggio, Alice Tarroni, Massimiliano Di Martino, Valeria Cappelli, Maria Teresa Gandolfo, Alessandro Valli, Daniela Verzola,

Cytokine Signaling Pathways and Interactions

Chronic elevation of circulating Interleukin-6 (IL-6) is observed in elderly individuals as well as in several illnesses, including chronic kidney diseases. A number of cells and tissues possess the ability to metabolize significant amounts of IL-6 in vitro. However, information on signals and mechanisms by which IL-6 is removed from blood in humans is still incomplete. To assess the individual role of splanchnic organs and kidney on IL-6 inter-organ exchange we used the IL-6 mass-balance technique across the hepato-splanchnic bed and kidney in six subjects with normal renal and liver function undergoing diagnostic venous catheterizations. Both in the hepatic and renal veins IL-6 levels were significantly lower (p = 0.041 and 0.038, respectively), than in the artery. The fractional extraction of IL-6, i.e., the percentage of arterial IL-6 extracted after a single pass, was greater across the splanchnic organs (18%) than across the kidney (8%). Accordingly, IL-6 plasma clearance across splanchnic organs was greater than across the kidney and the sum of kidney and splanchnic removal accounted for as much as 63% of the estimated adipocyte IL-6 release. Our data demonstrate that, although the individual contribution to removal is different, both splanchnic organs and kidneys affect in a significant way the disposal of IL-6 in humans. According, both liver and kidney dysfunction could affect the handling of this proinflammatory cytokine and favour a chronic inflammatory response.