title: Synaptic vesicle protein 2A predicts response to levetiracetam in patients with glioma.
abstract: OBJECTIVE
  To correlate SV2A expression in surgically removed tumor and peritumoral tissue of glioma patients with epilepsy with the clinical response to levetiracetam in a prospective cohort.
  
  
  METHODS
  Forty glioma patients with epilepsy were recruited. All patients had undergone surgery and were on levetiracetam monotherapy. Clinical characteristics were documented. Follow-up visits were scheduled at 3 and 6 months. Patients who responded to levetiracetam were compared to those who did not respond. Expression of SV2A was determined by means of immunohistochemistry in the surgically removed tumor and peritumoral tissue. Optical density (OD) was used to measure SV2A expression.
  
  
  RESULTS
  In total, 34 patients were eligible for analysis. Patients with a good response to treatment had significantly stronger SV2A expression as demonstrated by OD in tumor tissue (mean 44.5, SD 17.3) as well as in peritumoral tissue (mean 67.5, SD 7.8) than patients who did not show such a response (mean 8.1, SD 7.7, p < 0.01 and 45.6, SD 11.2, p < 0.01). SV2A expression predicted efficacy of levetiracetam monotherapy with an accuracy of 91%.
  
  
  CONCLUSIONS
  Our results suggest that expression of SV2A in tumor and peritumoral tissue is correlated to the clinical response to levetiracetam and predicts levetiracetam efficacy.
authors.affiliation: Department of Neurology, VU University Medical Center, Amsterdam, the Netherlands. marjolein.degroot@vumc.nl
authors.forename: M
authors.initials: M
authors.lastname: de Groot
authors.forename: E
authors.initials: E
authors.lastname: Aronica
authors.forename: J J
authors.initials: JJ
authors.lastname: Heimans
authors.forename: J C
authors.initials: JC
authors.lastname: Reijneveld
mesh_terms: D000328:Adult; D000368:Aged; D015153:Blotting, Western; D001932:Brain Neoplasms / Q000188:drug therapy* / Q000235:genetics; D015331:Cohort Studies; D004827:Epilepsy / Q000150:complications; D005189:False Positive Reactions; D005260:Female; D005500:Follow-Up Studies; D005910:Glioma / Q000188:drug therapy* / Q000235:genetics; D006801:Humans; D007150:Immunohistochemistry; D000077287:Levetiracetam; D008297:Male; D008562:Membrane Glycoproteins / Q000235:genetics*; D008875:Middle Aged; D009419:Nerve Tissue Proteins / Q000235:genetics*; D018697:Nootropic Agents / Q000627:therapeutic use*; D010889:Piracetam / Q000031:analogs & derivatives* / Q000627:therapeutic use; D011237:Predictive Value of Tests; D011446:Prospective Studies; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D008562:Membrane Glycoproteins; D009419:Nerve Tissue Proteins; D018697:Nootropic Agents; C076414:SV2A protein, human; D000077287:Levetiracetam; D010889:Piracetam