AKI is one of the most common organ dysfunctions in critically ill patients which adversely impacts short- and long-term clinical outcomes. It is frequently observed in patients after cardiac surgery (CS) involving cardiopulmonary bypass (CPB). Early diagnosis of AKI, preferably within 24 hours after ICU admission, is likely pivotal to the development of effective therapies. Traditional biomarkers like creatinine are late indicators of AKI, delaying diagnosis by days. Many AKI biomarkers, such as neutrophil gelatinase associated lipocalin (NGAL), cystatin C, interleukin (IL)-18 and kidney injury molecule-1 (KIM-1) have been unreliable in the real world.
A recent multicenter international investigation, the Sapphire study, reported the discovery and validation of two G1 cell-cycle arrest biomarkers (CCABs), tissue inhibitor of metalloproteinases (TIMP-2) and insulin-like growth factor binding protein (IGFBP-7).When combined, these CCABs detected AKI with a high level of accuracy and were found excellent in identifying patients at imminent risk of severe AKI.
IGFBP-7 is a secreted glycoprotein that binds to insulin growth factors. According to the Human Protein Atlas, IGFBP-7 is expressed in glomeruli and tubules of healthy humans and plays an important role in G1 cell-cycle arrest