Altered plasma prostaglandin E2 levels in epilepsy and in response to antiepileptic drug monotherapy

Prostaglandin E-2 (PGE(2)), a physiologically active lipid compound, is increased in several diseases characterized by chronic inflammation. To determine its significance in epilepsy-associated inflammation and response to antiepileptic drug (AED), we evaluated the plasma PGE(2) (median, pg/ml) levels in drug-free patients with epilepsy (N = 34) and patients receiving AED monotherapy (N = 55) in addition to that in healthy controls (N = 34). When compared to controls, plasma PGE(2) levels were significantly elevated in all drug-free patients independent of the type of epilepsy (137.2 versus 475.7 pg/ml, p < 0.0001). Among the patients receiving AED monotherapy, only valproate responders showed a significant decrease compared to both drug-free patients (232.1 versus 475.7 pg/ml, p < 0.01) as well as valproate non-responders (232.1 versus 611.9 pg/ml, p < 0.0001). Both responders and non-responders on phenytoin or carbamazepine monotherapy had elevated PGE(2) levels similar to drug-free patients. In addition, no difference was observed in plasma profiles of PGE(2) precursor, arachidonic acid among the groups. Our work presents the clinical evidence of the association between plasma PGE(2) levels and valproate efficacy in patients with epilepsy.