Cytokine phenotype, genotype, and renal outcomes at cardiac surgery

Background: Cardiac surgery modulates pro- and anti-inflammatory cytokine balance involving plasma tumour necrosis factor alpha (TNF alpha) and interleukin-10 (IL-10) together with urinary transforming growth factor beta-1 (TGF beta 1), interleukin-1 receptor antagonist (IL1ra) and tumour necrosis factor soluble receptor-2 (TNFsr2). Effects on post-operative renal function are unclear. We investigated if following cardiac surgery there is a relationship between cytokine (a) phenotype and renal outcome; (b) genotype and phenotype and (c) genotype and renal outcome. Since angiotensin-2 (AG2), modulates TGF beta 1 production, we determined whether angiotensin converting enzyme insertion/deletion (ACE I/D) genotype affects urinary TGF beta 1 phenotype as well as renal outcome. Methods: In 408 elective cardiac surgery patients we measured pre- and 24 h post-operative urinary TGF beta-1, IL1ra and TNFsr2 and pre- and 2 h post-operative plasma TNF alpha and IL-10. Post-operative responses were compared for each cytokine in patients grouped according to presence or absence of renal dysfunction defined as a drop from baseline eGFR of greater than 25% (as calculated by the method of modification of diet in renal disease (MDRD)) occurring (1) within the first 24 and (2) 48 postoperative hours (early renal dysfunction), (3) on the fifth postoperative day (late renal dysfunction) or (4) at any time throughout the 5 day postoperative period (early and late combined). Patient genotype was determined for TNF/G-308A, TGF beta 1-509 C/T, IL10/G-1082A and ACE I/D. Results: Post-operative plasma IL-10 and urinary TGF beta 1 responses were significantly higher in patients who developed early renal dysfunction. IL1ra and TNFsr2 responses were significantly lower 24 h post-operatively in patients who developed late renal dysfunction. Genotype did not alter cytokine phenotype or outcome. Conclusions/inferences: Cytokine profiling may help predict early and late renal dysfunction. Genotypes studied did not alter phenotype or outcome. (C) 2012 Elsevier Ltd. All rights reserved.