title: Immunophenotypic characterization of canine lymphoproliferative disorders.
abstract: One hundred ninety six dogs with spontaneously occurring lymphoproliferative disorders were immunophenotyped. Dogs with lymphoma (175) were determined to be derived from B-cells in 134/175 (76%), T-cells in 38/175 (22%) and 3/175 (2%) were null cells (non-reactive with any canine-specific lymphocyte antibody). Dogs with T-cell lymphomas were at significantly higher risk of relapse and early death compared with B-cell lineage lymphoma following therapy (52 vs. 160 days; p < 0.001 and 153 vs. 330 days; p < 0.001, respectively). Hypercalcemia was associated only with CD4+ lymphomas. A nonimmunoglobulin B-cell marker (B5), expressed in 95% of nonneoplastic lymphocytes, was expressed at a reduced level in 63% (64/104) of dogs with B-cell lymphoma. Dogs with lymphoma in which the B5 antigen was expressed below normal levels experienced shorter progression free survival (125 vs. 202 days; p < 0.05) and overall survival times (203 vs. 385 days; p < 0.05) than dogs with B-cell lymphoma in which the B5 antigen was expressed normally. Chronic lymphocytic leukemia in dogs was primarily associated with a CD8+ phenotype (8/12) and acute lymphoblastic leukemia was determined to be of either null cell (4/9) or T-cell (3/9) phenotype. Although canine and human non-Hodgkin's lymphoma are phenotypically similar, canine leukemia is phenotypically distinct from human leukemia. The development of canine-specific probes has facilitated a priori assessment of treatment outcome in dogs with lymphoma and may in the future contribute to the comparative understanding of leukemo- and lymphoma-genesis in these species.
authors.affiliation: Department of Companion Animal and Special Species, North Carolina State University, College of Veterinary Medicine, Raleigh 27606, USA.
authors.forename: D A
authors.initials: DA
authors.lastname: Ruslander
authors.forename: D H
authors.initials: DH
authors.lastname: Gebhard
authors.forename: M B
authors.initials: MB
authors.lastname: Tompkins
authors.forename: C B
authors.initials: CB
authors.lastname: Grindem
authors.forename: R L
authors.initials: RL
authors.lastname: Page
mesh_terms: D000818:Animals; D000954:Antigens, Surface / Q000032:analysis*; D001402:B-Lymphocytes / Q000737:chemistry*; D015415:Biomarkers; D004285:Dogs; D016130:Immunophenotyping; D007942:Leukemia, Experimental / Q000276:immunology* / Q000401:mortality; D008223:Lymphoma / Q000276:immunology* / Q000401:mortality; D011446:Prospective Studies; D016019:Survival Analysis
chemical_list: D000954:Antigens, Surface; D015415:Biomarkers