Nadir Creatinine in Congenital Anomalies of the Kidney and Urinary Tract (CAKUT): A Single-Center Experience

Background/Objectives: Congenital anomalies of the kidney and urinary tract (CAKUT) are the main cause of chronic kidney disease (CKD) requiring renal replacement therapy (RRT) in children, being the leading cause (50-70%) of end-stage renal disease (ESRD) in children and young adults. Our study aimed to assess the natural evolution of various antenatally diagnosed renal malformations and to identify potential prognostic factors to guide the therapeutic management of patients with CAKUT. Methods: We conducted a retrospective study on 205 children with CAKUT. For each patient, analyzing their medical records, we established the nadir value of serum creatinine, defined as the lowest creatinine level during the first year of life. We assessed the value of nadir creatinine as a prognostic marker in patients with CAKUT, and using an ROC curve, we also determined a threshold value of nadir creatinine that predicted progression to ESRD. Results: The male-to-female ratio was 2.8 to 1. The mean gestational age at detection was 29.85 weeks (+/- 6.71). A total of 36 patients (17.6%) had impaired renal function, of which 8 (3.9% of the total) progressed to ESRD. The mean nadir creatinine in patients with ESRD was 1.39 mg/dL. A nadir creatinine cut-off of 0.98 mg/dL had high sensitivity and specificity in identifying patients with progression to ESRD, with an AUC of 0.95 and a 95% confidence interval between 0.86 and 1.05 mg/dL. Conclusions: Our results support the value of nadir creatinine in predicting progression to ESRD, consistent with previously published data.