ABSTRACTS from 16th International COnference on ... - CRRT Online

"LATE BREAKING TRIALS" LUNCHEON
Diagnostic and Prognostic Stratification in the Emergency Department Using
Biomarkers of Intrinsic Acute Kidney Injury (AKI)
Jonathan Barasch and Kai Schmidt-Ott MD
Thursday, February 16
Educational Objectives:
1. Introduce current tools to diagnose acute kidney injury (AKI) in the emergency department, their limitations
and the potential of novel biomarkers of nephron damage
2. Report on the rationale, design, and results of a recent multicenter study to evaluate five urinary biomarkers
of intrinsic AKI
3. Outline future biomarker-aided diagnostic strategies and their potential therapeutic implications in the emergency
department
Content Description:
Acute kidney injury (AKI) associated with nephron damage (intrinsic AKI) at the time of hospital admission frequently
results in poor clinical outcomes during hospitalization. Currently, the diagnosis of intrinsic AKI is challenging,
because it usually relies on complex clinical information and serial measurements of a late functional
marker, serum creatinine, and its response to therapy. Urinary biomarkers of nephron damage may facilitate an
earlier and more accurate diagnosis of intrinsic AKI at the time of hospital admission and thereby enable early
risk stratification. We performed a multicenter prospective cohort study in two countries. We enrolled 1635 unselected
emergency department patients in the process of being admitted to the hospital. Five urinary biomarkers
(neutrophil gelatinase-associated lipocalin, uNGAL; kidney injury molecule 1, uKIM-1; liver-type fatty acid
binding protein, uL-FABP; interleukin 18, uIL-18; and cystatin C, uCysC) were measured on presentation and
analyzed for their ability to identify patients with intrinsic AKI and predict an unfavorable course in the hospital.
We found that all biomarkers were elevated in patients with intrinsic AKI. uNGAL was the most effective biomarker
in diagnosing intrinsic AKI with a specificity of 81% and a sensitivity of 68% at a 104 ng/ml cutoff.
uNGAL also displayed the closest correlation with the peak severity and duration of AKI. uNGAL and uKIM-1
most effectively predicted a composite in-hospital outcome of dialysis requirement or death. Importantly, both
uNGAL and uKIM-1 independently predicted the outcome when adjusted for known predictors, including serum
creatinine. Further analyses showed that the addition of either uNGAL or uKIM-1 to conventional prediction
strategies markedly improved net risk classification by up to 26% when compared with serum creatinine-based
prediction alone. More than 220 patients with low creatinine levels were upgraded to an intermediate-risk category
based on elevated biomarker levels. In addition, biomarkers sub-classified patients with elevated creatinine
levels into intermediate-risk and high-risk cases. Hence, urinary biomarkers of intrinsic AKI significantly
improve the diagnostic and prognostic stratification of patients undergoing triage in the emergency department.
Future studies will need to evaluate algorithms to implement renal biomarkers into clinical decision-making.
Suggested Reading:
1. Coca SG, Parikh CR. Urinary biomarkers for acute kidney injury: perspectives on translation. Clin J Am Soc
Nephrol 2008;3:481-90.
2. Haase M, Devarajan P, Haase-Fielitz A, Bellomo R, Cruz DN, Wagener G, Krawczeski CD, Koyner JL,
Murray P, Zappitelli M, Goldstein SL, Makris K, Ronco C, Martensson J, Martling CR, Venge P, Siew E, Ware
LB, Ikizler TA, Mertens PR. The outcome of neutrophil gelatinase-associated lipocalin-positive subclinical acute
kidney injury a multicenter pooled analysis of prospective studies. J Am Coll Cardiol 2011;57:1752-61.
3. Martin RK. Acute kidney injury: advances in definition, pathophysiology, and diagnosis. AACN Adv Crit
Care 2010;21:350-6.
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