From acute kidney injury to chronic kidney disease in children: maladaptive repair and the need for long-term surveillance - a literature review.

Pediatric Acute Kidney Injury (AKI) is an increasingly prevalent global health concern that extends far beyond a transient clinical event, posing a significant risk for long-term kidney dysfunction. This review consolidates current knowledge on the pathophysiological transition from pediatric AKI to Chronic Kidney Disease (CKD), critically evaluating the mechanisms of maladaptive repair, the utility of biomarkers, and the state of long-term surveillance strategies. The progression to CKD is driven by maladaptive repair, a process where the kidney's healing mechanisms become dysregulated following a severe or prolonged insult. This pathological cascade involves persistent inflammation, endothelial dysfunction, tubular epithelial cell cycle arrest, and the activation of myofibroblasts, culminating in irreversible interstitial fibrosis and nephron loss. The kidneys of preterm infants and neonates are particularly vulnerable; preterm infants may have incomplete nephrogenesis, leading to a reduced nephron endowment, while neonates exhibit functional immaturity. An AKI during these critical early periods can have a disproportionately large impact, amplifying the lifetime risk for hypertension and accelerated CKD. Evidence confirms that pediatric AKI survivors face a substantially increased risk of incident CKD, hypertension, and proteinuria, even when serum creatinine levels return to baseline. Current diagnostic tools, reliant on creatinine, are insensitive and lag behind the actual injury, hindering timely intervention. While novel biomarkers show promise for early AKI detection, their ability to predict the transition to CKD remains an area of active investigation. Major conclusions from this review highlight that pediatric AKI must be reframed as a sentinel event that necessitates a long-term approach to kidney health. However, care is often fragmented, a challenge compounded by a lack of pediatric-specific, evidence-based follow-up guidelines. Future progress depends on dedicated research into the unique aspects of maladaptive repair in developing kidneys, the validation of predictive biomarkers, and the development of targeted, age-appropriate therapies.