Methods and compositions for diagnosis and prognosis of renal injury and renal failure
The present invention relates to methods and compositions for monitoring, diagnosis, prognosis, and determination of treatment regimens in subjects suffering from or suspected of having a renal injury. In particular, the invention relates to using a measured urine concentration of one or more of TIMP2 and IGFBP7 in combination with one or more of a measured serum creatinine and a measured urine output, which results are correlated to the renal status of the subject, and can be used for diagnosis, prognosis, risk stratification, staging, monitoring, categorizing and determination of further diagnosis and treatment regimens in subjects suffering or at risk of suffering from an injury to renal function, reduced renal function, and/or acute renal failure.
1. A method for evaluating renal status in a subject not exhibiting AKI as measured by RIFLE I or F, comprising:
determining a measured value for a urine Metalloproteinase inhibitor 2 (TIMP2) concentration;
determining a measured value for a urine Insulin-like growth factor-binding protein 7 (IGFBP7) concentration;
determining a measured value for a serum creatinine concentration;
determining a measured value for urine output;
correlating the assay result to a risk of future AKI in the subject, wherein said correlation step comprises (i) classifying the subject as at a first risk of future AKI if the serum creatinine value is greater than or equal to 0.3 mg/dL or increased to greater than or equal to 150% (1.5-fold) of a baseline serum creatinine value for the subject, (ii) classifying the subject as at a second risk of future AKI if the urine output value is less than 0.5 mL/kg per hour for more than 6 hours, (iii) classifying the subject as at a third risk of future AKI that is greater than the first and second risks if the subject is classified at both the first risk and the second risk; and (iv) classifying the subject as at a fourth risk of future AKI that is greater than the first, second, and third risks if the subject is classified at the third risk and product of the Insulin-like growth factor-binding protein 7 value and the Metalloproteinase inhibitor 2 value is above a predetermined threshold determined from a population study to indicate an increased risk of future AKI.
2. A method according to claim 1 , further comprising treating the patient if the patient is at the fourth risk, wherein the treatment comprises one or more of initiating renal replacement therapy, withdrawing delivery of compounds that are known to be damaging to the kidney, delaying or avoiding procedures that are known to be damaging to the kidney, and modifying diuretic administration.