Assessment of Urinary Kidney Injury Molecule-1 as an Indicator of Early Renal Insult in Children with Cystic Fibrosis

BACKGROUND: The risk of acute kidney injury in cystic fibrosis (CF) patients is due to renal tubular affection by CFTR gene. AIM: Our study aimed at early detection of renal impairment in CF patients, to enable careful monitoring and adjustment of nephrotoxic medications. METHODS: Fifty patients with CF were enrolled in our study; they were age- and sex-matched to 40 healthy control children. All subjects were screened by urine analysis, measurements of kidney function tests, fractional excretion of sodium, β2-microglobulin (beta-2-M) excretion, and renal ultrasound examination. Urinary kidney injury molecule-1 (KIM-1) was assayed using ELISA technique. RESULTS: Both urinary beta-2-M and KIM-1 concentrations were significantly higher in CF patients compared to the control group (p < 0.001). The duration of the disease was significantly positively correlated with the urinary beta-2-M and KIM-1 levels (r = 0.6 and 0.7, respectively; p < 0.01). CONCLUSIONS: Our results showed that urinary KIM-1 can be considered as a sensitive early indicator of acute renal injury.