title: Effects of L-asparaginase on plasma amino acid profiles and tumor burden in cats with lymphoma.
abstract: BACKGROUND
  L-Asparaginase (Elspar(a)), is an Escherichia coli-derived enzyme that depletes lymphoma cells of asparagine, inhibiting protein synthesis and resulting in cell death. The single agent response rate in cats with lymphoma and impact of L-asparaginase on plasma amino acid concentrations is unknown.
  
  
  OBJECTIVE
  L-Asparaginase significantly reduces plasma asparagine concentrations and has demonstrable efficacy against untreated lymphoma in cats.
  
  
  METHODS
  Thirteen cats with confirmed lymphoma (LSA) of any anatomic site were given 1 dose 400 IU/kg IM) of L-asparaginase for initial LSA treatment.
  
  
  METHODS
  Plasma collected at 0, 2, and 7 days after L-asparaginase therapy was assayed for ammonia, asparagine, aspartic acid, glutamine, and glutamic acid concentrations. Cats were restaged 7 days later to assess tumor response.
  
  
  RESULTS
  Eight cats had T-cell LSA, 4 cats had B-cell LSA, and 1 cat's immunophenotype was unknown. Two complete and 2 partial responses to L-asparaginase were seen. Four cats had stable disease, and 5 cats had progressive disease. Ammonia and aspartic acid concentrations were increased from baseline at 2 and 7 days posttreatment. Asparagine concentrations were decreased from baseline at 2 days but not 7 days posttreatment. Glutamic acid concentrations were increased at day 2 compared to day 7 posttreatment but not compared to baseline. Glutamine concentrations were unchanged.
  
  
  CONCLUSIONS
  L-asparaginase significantly reduced asparagine concentrations within 2 days of treatment, but this effect was lost within 7 days. The apparent overall response rate of feline LSA to L-asparaginase in this study was 30%.
authors: Department of Small Animal Clinical Sciences, College of Veterinary Medicine, The University of Tennessee, C247 Veterinary Teaching Hospital, 2407 River Drive, Knoxville, TN 37996-4544, USA. aleblanc@utk.edu
authors: A K
authors: AK
authors: LeBlanc
authors: S K
authors: SK
authors: Cox
authors: C A
authors: CA
authors: Kirk
authors: S J
authors: SJ
authors: Newman
authors: J W
authors: JW
authors: Bartges
authors: A M
authors: AM
authors: Legendre
mesh_terms: D000596:Amino Acids / Q000097:blood*; D000818:Animals; D000970:Antineoplastic Agents / Q000627:therapeutic use; D001215:Asparaginase / Q000627:therapeutic use*; D002371:Cat Diseases / Q000097:blood* / Q000188:drug therapy* / Q000473:pathology; D002415:Cats; D005260:Female; D008223:Lymphoma / Q000097:blood / Q000188:drug therapy / Q000473:pathology / Q000662:veterinary*; D008297:Male
chemical_list: D000596:Amino Acids; D000970:Antineoplastic Agents; D001215:Asparaginase