Abstract: Objective To examine serum ubiquitin carboxyl-terminal esterase-L1 (UCH-L1) levels in coarctation patients with and without cardiopulmonary bypass(CPB), and to evaluate whether UCH-L1 was a useful marker in predicting the brain injury associated with CPB after aortic arch operation.Methods Thirty-nine consecutive patients subjected to aortic repairs were enrolled, 22 patients received SCP(group B) and 17 did not receive CPB(group A). Serum was collected at six time points (after induction of anesthesia; closure of chest; 2 h, 8 h, 24 h, 48 h after operation). UCH-L1, S100β and neuron specific enolase (NSE) levels were measured by using a sandwich enzyme-linked immunosorbent assay. Neurologic function scores were recorded at 8 h after operation,6 h after extubation and before discharge.Results Baseline UCH-L1 protein levels in serum were similar to those of all groups[group A (0.184±0.066) μg/L, group A (0.194±0.067) μg/L. The concentrations of UCH-L1 in group B were elevated at 2 hours after operation significantly compared with group A[group A (0.238±0.067) μg/L vs group B (0.327±0.151) μg/L, P<0.05]and reached a peak at 8 h after operation. At 24 hours after operation, levels of UCH-L1 had no significant differences between the two groups[group A (0.208±0.078) μg/L vs group B(0.201±0.081) μg/L, P>0.05]. The correlation between CPB time and peak concentrations of UCH-L1 in group B was found to be statistically significant (r=0.575, P=0.005). Permanent neurological complications were not detected in all patients after operation.Conclusion Pediatric operation of the aortic arch with SCP causes a significantly greater increase in UCH-L1 serum levels than those of off-pump surgery and correlates with CPB duration. UCH-L1 can be a potential useful biomarker for the prediction of brain injury after CPB.

Key words: coarctation, brain, ubiquitin carboxyl-terminal esterase-L, S100β, neuron specific enolase