Acute Kidney Injury, Renal Replacement Therapy, and Sepsis after Cardiac Surgery: The Roles of TIMP2*IGBP7 and Mid-Regional Pro-Adrenomedullin

Identifying a panel of markers detecting kidney injury before the glomerular filtration rate (GFR) reduction is the challenge to improve the diagnosis and the management of acute kidney injury (AKI) in septic patients. This study evaluated the roles of tissue inhibitor metal proteinase, insulin growth factor binding protein (TIMP2*IGFBP7), and mid-regional pro-adrenomedullin (MR-proADM) in AKI patients. Patients and Methods: This study was prospectively conducted in the Intensive Care Unit (ICU) enrolling 230 patients who underwent cardiac surgery. Biomarkers were evaluated before and after 4 hours of the cardiac surgery. Results: Whereas urine and creatinine alterations appeared at 23.2 (12.7 – 36.5) hours, after cardiac surgery, urinary TIMP2*IGBP7 levels were higher at 4 hours in AKI patients (1.1±0.4 mg/l vs 0.08±0.02 mg/l; p 2 mg/l increases the AKI risk within the following 24 hours, clearly identifying the population at high risk of renal replacement therapy (RRT). In patients with sepsis, MR-proADM levels were 2.3 nmol/l (0.7–7.8 nmol/l), with the highest values observed in septic shock [5.6 nmol/l (3.2–18 nmol/l)] and a better diagnostic profile than procalcitonin and C-reactive protein to identify septic patients. MR-proADM values >5.1 nmol/l and urine TIMP2*IGBP7 levels > 2 mg/l showed a significantly faster progression to RRT, with a mean follow-up time of 1.1 days. Conclusions: TIMP2*IGBP7 and MR-proADM precociously diagnose AKI in septic patients after cardiac surgery, giving prognostic information for RRT requirement.