title: Cytochemical and immunocytochemical characterization of blood cells and immunohistochemical analysis of spleen cells from 2 species of frog, Rana (Aquarana) catesbeiana and Xenopus laevis.
abstract: BACKGROUND
  Mechanisms of amphibian diseases are not characterized as well as those in domestic mammalian species. Antemortem laboratory testing is limited in frogs, presenting a diagnostic challenge to zoos, laboratories, and exotic veterinarians.
  
  
  OBJECTIVE
  This study aimed to characterize blood cells and splenic cells from 2 anuran species based on characteristics identified by Wright staining, cytochemical staining, and immunochemical analysis and on histologic examination of spleens.
  
  
  METHODS
  Blood specimens and spleens were obtained from 2 species of frog, the American bullfrog (Rana [Aquarana] catesbeiana) and the African clawed frog (Xenopus laevis). Blood smears were evaluated after Wright staining and cytochemical staining for α-naphthyl butyrate esterase (NBE), chloroacetate esterase (CAE), myeloperoxidase (PER), Sudan black B (SBB), and leukocyte alkaline phosphatase (LAP) reactions and for immunoreactivity for antibodies against CD3ε, CD79a, and BLA.36 antigens. Histologic sections of spleen were evaluated after staining with H&E and for immunoreactivity for CD3ε, CD79a, and BLA.36 antigens.
  
  
  RESULTS
  In bullfrogs, neutrophils, eosinophils, and monocytes were positive for some or all of the following: NBE, CAE, PER, and SBB; lymphocytes occasionally were positive for CAE. In clawed frogs, neutrophils, basophils, and monocytes were positive for some or all of the following: NBE, CAE, PER, and SBB; eosinophils occasionally were positive for CAE and PER, and lymphocytes were negative for all cytochemical stains. LAP was not a useful marker for any leukocyte type. In both species, peripheral blood lymphocytes were strongly immunoreactive for CD3ε, CD79a, and BLA.36. In splenic tissue, histologic patterns varied and there was diffuse immunoreactivity for CD79a and BLA.36 with focal reactivity for CD3ε, but with different distribution patterns in each species.
  
  
  CONCLUSIONS
  Cytochemical and immunochemical analysis of cells may be helpful in identification and characterization of amphibian blood cells and splenic cells for evaluation of the health of these animals.
authors.affiliation: Department of Comparative Pathobiology, School of Veterinary Medicine, Purdue University, West Lafayette, IN 47907, USA.
authors.forename: Nelson K
authors.initials: NK
authors.lastname: Bricker
authors.forename: Rose E
authors.initials: RE
authors.lastname: Raskin
authors.forename: Christine L
authors.initials: CL
authors.lastname: Densmore
mesh_terms: D000469:Alkaline Phosphatase / Q000032:analysis; D000818:Animals; D017252:CD3 Complex / Q000276:immunology; D051925:CD79 Antigens / Q000276:immunology; D002265:Carboxylic Ester Hydrolases / Q000032:analysis; D007150:Immunohistochemistry / Q000662:veterinary; D007958:Leukocyte Count / Q000662:veterinary; D007962:Leukocytes / Q000737:chemistry / Q000166:cytology*; D009195:Peroxidase / Q000032:analysis; D011446:Prospective Studies; D011892:Rana catesbeiana / Q000097:blood / Q000276:immunology* / Q000378:metabolism; D013154:Spleen / Q000201:enzymology / Q000276:immunology* / Q000473:pathology; D014982:Xenopus laevis / Q000097:blood / Q000276:immunology* / Q000378:metabolism
chemical_list: D017252:CD3 Complex; D051925:CD79 Antigens; D009195:Peroxidase; D002265:Carboxylic Ester Hydrolases; D000469:Alkaline Phosphatase