Validity of Serum Zinc/Copper Ratio as a Potential Novel Biomarker in Childhood Epilepsy.

Serum zinc and the zinc/copper ratio were significantly lower in epileptic children than in controls (p < 0.001). Significantly lower zinc and zinc/copper ratio and higher copper levels were found in children treated with levetiracetam/sodium valproate/oxcarbazepine than those treated with levetiracetam alone or combined with sodium valproate (p < 0.05 for all). Epileptic children, particularly pharmacoresistant, exhibited significant negative correlations between the serum levels of zinc and copper (r = -0.279, p = 0.005, and r = -0.363 and p = 0.010, respectively). At cutoff value of zinc/copper ratio < 1.118 in diagnosing children with epilepsy, it gives a sensitivity of 64% and a specificity of 85% with the AUC = 0.8092. At cutoff value of zinc/copper ratio ≤ 0.7826 in distinguishing pharmacoresistant epilepsy, it produced 52% sensitivity, 64% specificity with AUC = 0.576 Conclusions: Low zinc and high copper levels were associated with childhood epilepsy especially those with pharmacoresistant type and treated with Oxcarbazepine. Zinc/copper ratio might be a potential biomarker in diagnosing childhood epilepsy and to some extent in predicting pharmacoresistant type.