Advances in the Investigation of Biomarkers for Subclinical Acute Kidney Injury

Acute kidney injury (AKI) can result from a variety of etiologies (e.g., ischemia, toxicity, and sepsis) and is characterized by high rates of morbidity and mortality. As the diagnostic criteria for AKI, an increase in serum creatinine (SCr) concentration and/or a decrease in urine output often lags behind. However, early detection and timely treatment of AKI are crucial to reduce the mortality. AKI diagnosed only by elevated markers of tubular/glomerular injury is called "Subclinical AKI" means elevated markers of glomerular/tubular injury, but not accompanied by elevated SCr. In recent years, there have been many studies on biomarkers for early diagnosis of AKI, and several novel biomarkers have emerged. This manuscript discusses some important biomarkers, such as neutrophil gelatinase-associated lipocalin (NGAL), kidney injury molecule 1 (KIM-1), liver-type FABP (L-FABP), proenkephalin (Penkid), metalloproteinase 2 (TIMP-2), insulin-like growth factor binding protein 7 (IGFBP7) and Dickkopf-3 (DDK3). We analyze their advantages, limitations and clinical application prospects in subclinical AKI.