Methods and compositions for diagnosis and prognosis of renal injury and renal failure

A method for evaluating renal status in a subject not currently receiving dialysis and that meets the definition of RIFLE stage I or F for recovery from acute kidney injury, the method comprising:

• performing an assay configured to detect Chitinase-3-like protein 1 on a body fluid sample obtained from the subject to provide an assay result;
• correlating the assay result to a likelihood of the subject recovering from RIFLE stage I or F acute kidney injury as defined by the subject having a maximum RIFLE stage of R over a recovery period beginning 12 hours after the sample was obtained and lasting at least 24 hours by:
• comparing the assay result to a threshold value obtained from a population study, wherein the threshold separates the population into a first subpopulation above the threshold and a second subpopulation at or below the threshold, the second subpopulation being at an increased likelihood of recovering from acute kidney injury relative to the first subpopulation, and
• assigning the subject to the first subpopulation or the second subpopulation;
• and
• treating the subject based on the subpopulation of individuals to which the subject is assigned, wherein when the assay result assigns the subject to the first subpopulation, the subject is treated for non-recovery from acute kidney injury by initiation of renal replacement therapy.

A method for evaluating renal status in a subject not currently receiving dialysis and that meets the definition of RIFLE stage I or F for persistence of acute kidney injury, the method comprising:

• performing an assay configured to detect Chitinase-3-like protein 1 on a body fluid sample obtained from the subject to provide an assay result;
• correlating the assay result to a likelihood of the subject having persistent RIFLE stage I or F acute kidney injury as defined by the subject having a minimum RIFLE stage of I over a persistence period beginning within 72 hours after the sample was obtained by:
• comparing the assay result to a threshold value obtained from a population study, wherein the threshold separates the population into a first subpopulation above the threshold and a second subpopulation at or below the threshold, the first subpopulation being at an increased likelihood of having persistent acute kidney injury relative to the second subpopulation, and
• assigning the subject to the first subpopulation or the second subpopulation;
• and
• treating the subject based on the subpopulation of individuals to which the subject is assigned, wherein when the assay result assigns the subject to the first subpopulation, the subject is treated for persistent acute kidney injury by initiation of renal replacement therapy.