NGAL and Cystatin C levels, as early biomarkers of contrast-induced nephropathy in pediatric catheter angiography patients

We prospectively enrolled 46 children, aged between 3 months to 16 years (9 cyanotic, 37 acyanotic), undergoing elective cardiac catheterization and angiography with low osmolality non-ionic contrast media (IOPROMİD 769 mg/ml) administration in our study. Serial urine and plasma samples (baseline, 4th , 4-8th , 24th , and 48th hours after the procedure) were analyzed for serum creatinin (Cr), serum Sistatin C, serum and urine NGAL (Neutrophil gelatinase-associated lipocalin). We aimed to assess contrast-induced nephropathy (CIN) prevalence, risk factors and if serum Cystatin C, serum NGAL and urine NGAL levels are early predictive biomarkers of CIN in pediatric catheter angiography patients after the procedure.CIN, defined as an increase of serum Cr concentration of 0,5 mg/dl or 25% above baseline after contrast medium administration, was found in 16 (34,7%) subjects. When classified subjects into those with and without CIN, the volume of contrast media (cc/kg) was higher in the patients with CIN than in those without CIN (5.,0±2,3cc/kg vs 3,7±2,0 cc/kg, p: 0,051). Using a cutoff value of 4,09 cc/kg for contrast media volume for prediction of CIN; sensitivity, specificity, negative and positive predicted values were found 68,7%; 70%; 50,6%; %50,1, respectively.Although not statistically significant, age, weight, height, body surface area were higher (p:0,169; p:0,228; p:0,088; p:0,167 respectively) and also presence of anemia, female gender were most common (p:0,189; p:0,152, respectively) in the patients with CIN than in those without CIN. We found statistically significant higher density of baseline urine levels in the CIN group (p<0,001).Although not statistically significant, syanotic patient frequency was higher in the CIN group (31,3% vs. 13,3%, p:0,241). When classified subjects into those cyanotic and acyanotic, there was not a statistically significant difference in nephrotoxicity biomarker values between these two groups in 4th, 4-8th, 24th, 48th hours.For the early detection of CIN, the increase of the serum NGAL level that stay constant after 24 hours, the increase of urine NGAL/ urine Cr level in 4 th -8 th hours and the increase of serum sistatin C level in 24th hour after the process might be taken into consideration (p:0,289; p:0,333; p:0,134 respectively), but it is shown that their diagnostic efficiency is not superior to that of serum Cr, statistically.Key words: Contrast-induced nephropathy, NGAL, Cystatin C