Kinetics of plasmatic cytokines and cystatin C during and after hemodialysis in septic shock-related acute renal failure

INTRODUCTION: Cystatin C could be a relevant residual glomerular filtration rate marker during hemodialysis (HD), and a high cytokine plasma (p) rate is associated with an increase in mortality during sepsis. To the best of our knowledge, cytokines and cystatin C kinetics during and after HD during sepsis have never been studied. In this study, we described p cytokines and cystatin C variations during and after hemodialysis in septic-shock patients with acute kidney injury (AKI). METHODS: Ten patients, from two tertiary ICUs, with septic shock-related AKI, according to RIFLE class F, were studied. In this prospective observational study, blood samples were collected at the start, after 1 hour, 2 hours, and at the end of HD with a polymethymethacrylate (PMMA) hemodialyzer (D0, D1, D2, and endD), and 30, 60, 90, 120, and 180 min after HD (postD0.5, postD1, postD1.5, postD2, and postD3). We measured p interleukins (IL)-6, IL-8, IL-10, cystatin C, and albumin. Results are expressed as variations from D0 (mean ± SD). RESULTS: During HD, p[IL-6] did not vary significantly, whereas p[IL-8] and p[IL-10] reductions by D1 were 31.8 ± 21.2% and 36.3 ± 26%, respectively (P < 0.05 as compared with D0). At postD3, p[IL-8] and p[IL-10] returned to their initial values. p[Cystatin C] was significantly reduced from D1 to postD1, with a maximal reduction of 30 ± 6.7% on D2 (P < 0.05). Norepinephrine infusion rate decreased from D0 to postD3 (0.65 ± 0.39 to 0.49 ± 0.37 μg/kg/min; P < 0.05). CONCLUSIONS: HD allows a transient and selective decrease in p cytokines, which are known as being correlated with mortality during septic shock. Because of a significant decrease in p cystatin C during HD, this should not be considered as an accurate marker for residual glomerular filtration rate during septic acute renal failure when receiving HD with a PMMA hemodialyzer.