Acute Kidney Injury in Adult Idiopathic Nephrotic Syndrome

Objective: This study aims to investigate the epidemiology, clinical and histological features, and prognosis of acute kidney injury (AKI) according to RIFLE classification in adult patients with idiopathic nephrotic syndrome.

Methods: In this retrospective study, 277 patients with idiopathic nephrotic syndrome were reviewed from June 2005 to June 2009.

Results: Fifty-one (18%) patients entered RIFLE class Risk (AKI-R); 24 (9%) patients entered RIFLE class Injury (AKI-I); and 20 (7%) patients entered RIFLE class Failure (AKI-F). Logistic regression analysis showed that severe hypoalbuminemia, increase in age, and being male were risk factors of AKI. Cumulative recovery rates in 3 months for groups AKI-R, AKI-I, and AKI-F were 95%, 100%, and 94%, respectively (p  =  0.21). The mean time to recovery for groups AKI-R, AKI-I, and AKI-F was 20 ± 3, 25 ± 4, and 30 ± 5 days, respectively. Cumulative complete remission rates in 3 months for groups AKI-R, AKI-I, and AKI-F were 92%, 86%, and 65%, respectively (p  =  0.002). The mean time to remission for groups AKI-R, AKI-I, and AKI-F was 28 ± 3, 39 ± 6, and 62 ± 8 days, respectively.

Conclusion: AKI is not uncommon in adult idiopathic nephrotic syndrome. More severe AKI was associated with longer time of nephrotic syndrome complete remission. Renal function can recover completely in most of the patients.