Application of plasma clearance of iohexol in evaluating renal function in chinese children with chronic kidney disease.

OBJECTIVE

To evaluate the accuracy of plasma clearance of iohexol (PCio) for glomerular filtration rate (GFR) measurement in Chinese children with chronic kidney disease (CKD) and assess the feasibility of single-blood-sample method or dried capillary blood spots in determining the PCio.

METHODS

Totally 45 CKD children were included,in whom the (99m) Technetium-diethylenetriaminepentaacetic acid ((99m)Tc-DTPA) plasma clearance and iohexol plasma clearance were simultaneously determined. Blood samples were obtained 2,4,and 5 hours after injection. In addition, we also evaluated the efficacy of single blood sample method and dried blood spots method in iohexol plasma clearance.

RESULTS

Forty-five CKD children completed the iohexol plasma clearance and thirty-six children completed the (99m)Tc-DTPA plasma clearance at the same time among them. Thirteen children finished the iohexol dried blood spot clearance. The correlation coefficient between (99m)Tc-DTPA plasma clearance and iohexol plasma clearance was 0.941 and the bias was (6.53 ± 11.6) ml/ (min·1.73 m²), and the intraclass correlation coefficient (ICC) was high (ICC=0.947). The correlation between iohexol single-sample plasma clearance and double samples was also strong (r=0.958), with the bias being (4.26 ± 9.06)ml/(min·1.73 m²) and the ICC being 0.970. The iohexol clearance by dried blood spots showed a good correlation with the serum iohexol clearance (r=0.950), with the bias still being small [(0.48 ± 10.89)ml/(min·1.73 m²)].

CONCLUSIONS

Iohexol plasma clearance has satisfactory agreement with (99m)Tc-DTPA plasma clearance and can be used as an ideal method to measure GFR in CKD children. The single-sample method and dried blood spots method make iohexol plasma clearance more convenient and practical.