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

A method of detecting a marker of acute kidney injury in a subject under clinical evaluation for kidney injury, the method comprising

• performing an assay to detect a level of matrix metalloproteinase-9:tissue inhibitor of metalloproteinase 2 (MMP9:TIMP2) complex within a urine, whole blood, plasma, or serum sample obtained from the subject.

A method of treating a subject for acute kidney injury, the method comprising:

• selecting the subject for treatment based on the subject's having a matrix metalloproteinase-9:tissue inhibitor of metalloproteinase 2 (MMP9:TIMP2) complex level in a body fluid sample being above a predetermined threshold indicating an increased risk of having acute kidney injury within 7 days from the time the sample was obtained;
• and
• treating the subject with a compatible treatment regimen, wherein the compatible treatment regimen comprises one or more of initiating renal replacement therapy, withdrawing delivery of compounds that are known to be damaging to the kidney, delaying procedures that are known to be damaging to the kidney, modifying diuretic administration, and monitoring kidney reperfusion.