Consensus Report from Oncology Advisory Board Meeting

Strategies for Prevention and Management of CI-AKI and the Role of Contrast in Oncology CT Settings • 11 added an absolute change in serum Cr of ≥0.3 mg/dl and removed criteria for GFR. The AKIN system also omitted the stages “loss” and “end-stage renal disease”, as these were outcomes rather than stages (Fig. 2). However, it needs to be clear that the term AKI covers a spectrum from subclinical to clinical kidney damage (i.e., not just overt injury). Clinicians should use consistent criteria to diagnose and classify AKI, based on the latest guidelines (i.e., using a serum Cr cutoff of 0.3 mg/dl or 25%). Although there is concern that these cutoffs would result in a substantial increase in the number of reported cases, these patients need to have their risk recognized and managed, to avoid the long-term health and financial burden of progressive kidney disease. The patients with CI-AKI suffer from significant morbidity and mortality. The term CI-AKI is more universal currently and the term contrast nephropathy is no longer in use as it is imperative that the terminology is homogenized. In addition, if the terminology is not consistent, comparison of the data will not be possible in this era of large database and pragmatic trials happening all over the world. Biomarkers in CI-AKI To minimize the risk, healthcare professionals need to work together across disciplines, with nephrologists, radiologists, oncologists, and cardiologists, all involved in multidisciplinary decisions. Everyone needs to understand and recognize the potential long-term effects of nephron loss, and take steps to minimize such damage, even if the clinical consequences are not immediately apparent. Biomarkers are desperately needed to help clinicians identify patients with kidney damage before serum Cr levels are affected. While the kidney dysfunction can be indicated by Cr level, kidney damage will be identified with the help of biomarkers. Box 1 mentions AKI biomarkers. The Nephro Check diagnostic test for TIMP-2 and IGFBP-7 has been approved in the USA by the FDA. Damage to kidneys can happen even when the Cr levels do not rise. Subclinical AKI, with no Cr rise but raised biomarkers is still AKI and needs attention. eGFR cannot be used to describe acute changes in kidney function. In this regard, direct measurement of GFR is advised. However, eGFR is a excellent tool to describe baseline kidney function in steady state conditions and it is more reliable than Cr level. Evaluation of renal functional reserve can further help to clarify the conditions of the kidneys. The CKD-EPI formula gives the most accurate eGFR: eGFR= 141 × min (Scr/k,1) a × max (Scr/k,1) −1.209 × 0.993 age × (1.018 if Female) × (1.159 if Black) where SCr is serum creatinine (mg/dL), k is 0.7 for females and 0.9 for males, a is -0.329 for females and -0.411 for males, min indicates the minimum of SCr/k or 1, and max indicates the maximum of SCr/k or 1. If serum Cr is measured in µmol/l, divide the Cr value obtainedby88.The simplified formula for eGFR is available online ( https://www.kidney.org/apps/professionals/egfr-calculator) . Figure 3 depicts biomarkers dynamics in CI-AKI. Box 1: AKI biomarkers. Inflammatory biomarkers Neutrophil gelatinase-associated lipocalin (NGAL) Interleukin-18 (IL-18) Tubular proteins Kidney injury molecule-1 (KIM-1)  Na+/H+ exchanger isoform 3 (NHE3) Surrogate markers of tubular injury Urinary low molecular weight proteins escaping reabsorption on tubular injury (cystatin C, or microglobulin, and retinol binding protein) Urinary tubular enzymes released on tubular injury (NAG: N-acetyl- -D-glucosaminidase; AP: alkaline phosphatase; GT: gamma-glutamyl- transferase, etc.) Fig. 2. Acute kidney injury network (AKIN) diagnostic criteria and classification/staging for AKI. AKI: acute kidney injury; SCr: serum creatinine Source: Mehta R, et al . Crit Care. 2007; 11: R31. JB6810 01-2016AKI in cancerpatients Acute Kidney Injury Network (AKIN) Mehta R et al. Crit Care 2007; 11 : R31. AKI: acute kidney injury SCr: serum creatinine Diagnostic criteria. An abrupt (within 48 hours) reduction in kidney function currently defined as an absolute increase in SCr of more than or equal to 0.3 mg/dl (≥26.4 μmol /l), a percentage increase in SCr of more than or equal to 50% (1.5-fold from baseline), or a reduction in urine output (documented oliguria of less than 0.5 ml/kg/hour for more than 6 hours). Classification/staging for AKI. Stage Serum creatinine criteria Urine output criteria 1 Increase in SCr of more than or equal to 0.3 mg/dl (≥26.4 μmol /l) or increase to more than or equal to 150% to 200% (1.5- to 2-fold) from baseline Less than 0.5 ml/kg/hour for more than 6 hours 2 Increase in SCr to more than 200% to 300% (>2- to 3-fold) from baseline Less than 0.5 ml/kg/hour for more than 12 hours 3 Increase in SCr to more than 300% (>3-fold) from baseline (or SCr of more than or equal to 4.0 mg/dl [≥354 μmol /l] with an acute increase of at least 0.5 mg/dl [44 μmol /l]) Less than 0.3 ml/kg/hour for 24 hours or anuria for 12 hours