Urinary apolipoprotein M as a biomarker of acute kidney injury in children undergoing heart surgery.

Aim: To investigate whether apoM is excreted in urine of children undergoing heart surgery and the potential of apoM as early biomarker of acute kidney injury (AKI).

Materials & Methods: Urine was collected in children undergoing heart surgery. ApoM was measured with ELISA. U-apoM was characterized by gel filtration chromatography and western blotting.

Results: ApoM was excreted into the urine 0-4 h postoperatively as the full-length apoM in particles smaller than plasma HDL. At 0 h, U-apoM predicted AKI with an area under the receiver-operating characteristics curve of 0.70 (p < 0.018). Sensitivity was 0.71 and specificity was 0.68 at a cutoff level at 1.45 nmol/l.

Conclusion: ApoM is excreted in the urine of children after cardiac surgery. Its potential as biomarker of AKI deserves exploration.