Acute and chronic kidney injury in nephrolithiasis

PURPOSE OF REVIEWNephrolithiasis is a common systemic disease associated with both acute kidney injury (AKI) and chronic kidney disease (CKD). The purpose of this review is to discuss recent publications regarding nephrolithiasis-associated kidney damage, with an emphasis on AKI. RECENT FINDINGSNephrolithiasis is not a common cause of adult AKI (1–2% of cases), although it may be a more important factor in young children (up to 30%). The primary mechanism of nephrolithiasis-associated AKI is obstructive nephropathy, and factors on presentation with obstructive uropathy predict the likelihood of long-term renal recovery. Crystalline nephropathy is another potential pathway in certain circumstances that is often associated with a worse outcome. Recent studies have elucidated additional pathways whereby calcium oxalate crystals can cause acute injury, implicating innate immunity and intracellular inflammasome pathways. Several large cohort studies have demonstrated an independent association of nephrolithiasis with CKD and end-stage renal disease, although the effect size is modest. Urologic comorbidities, urinary infection, and shared underlying risk factors (e.g., diabetes, hypertension) all impact nephrolithiasis-associated CKD risk. SUMMARYObstructive nephropathy and crystalline nephropathy both contribute to nephrolithiasis-associated AKI, although the latter appears to have a worse prognosis. Nephrolithiasis is an independent, albeit small, risk factor for CKD. Further study is needed to clarify the incidence and mechanisms of nephrolithiasis-associated AKI, and the relationship between nephrolithiasis-associated AKI and CKD.