Acute kidney injury (AKI) is a common and serious clinical syndrome associated with significant morbidity and mortality, particularly in hospitalized and critically ill patients. Traditionally defined by rises in serum creatinine and reductions in urine output per the KDIGO 2012 Clinical Practice Guidelines for Acute Kidney Injury, AKI diagnosis has been limited by the inherently delayed nature of these markers, which reflect functional decline only after substantial nephron injury has already occurred.
The International Society of Nephrology has highlighted the urgent need for earlier biomarkers capable of detecting subclinical kidney injury. In recent years, several promising candidates have entered clinical evaluation. NGAL was studied in the TRIBE-AKI consortium (Parikh et al., Journal of the American Society of Nephrology, 2011), demonstrating that urinary NGAL predicted AKI after cardiac surgery up to 48 hours before creatinine elevation in both adults and children.
Kidney injury molecule-1 (KIM-1) has been validated in multiple cohorts as a marker of proximal tubular injury. The ASSESS-AKI study (Coca et al., JAMA Internal Medicine, 2012) examined a panel of novel biomarkers including KIM-1 and NGAL in hospitalized patients with AKI and demonstrated independent associations with long-term CKD development and mortality.
The combination of urinary IGFBP7 and TIMP-2, commercialized as NephroCheck (Astute Medical), received FDA clearance in 2014 based on data from the SAPPHIRE study (Kashani et al., Critical Care, 2013), a multicenter prospective study in 728 critically ill patients. This approach shifts AKI detection from a damage-response paradigm toward a stress-detection model, with applications in preemptive management of high-risk surgical and ICU patients.
ISN has underscored the need for standardized biomarker validation across diverse patient populations and clinical settings. The ISN AKI 0by25 global snapshot study, published in PLOS Medicine (2017, Mehta et al.), also identified the critical gap between AKI recognition and biomarker availability in LMICs, reinforcing that advances in early detection must be accompanied by equitable access strategies to translate into population-level benefit.