title: Immunohistochemical identification of B and T lymphocytes in formalin-fixed, paraffin-embedded feline lymphosarcomas: relation to feline leukemia virus status, tumor site, and patient age.
abstract: The lymphocyte phenotype of 70 formalin-fixed, paraffin-embedded feline lymphosarcomas (LSAs) was determined immunohistochemically using a T cell polyclonal antibody, and a B cell monoclonal antibody. Forty-seven of 70 (67%) tumors were T cell, 19/70 (27%) were B cell, and 4/70 (6%) did not stain with either marker. Thirty-eight of 70 (54%) tumors were positive for feline leukemia virus (FeLV) antigen by immunohistochemistry (IHC), and 52/70 (74%) tumors were positive for FeLV DNA using the polymerase chain reaction (PCR). B cell tumors were as frequently FeLV-positive as T cell tumors using either IHC or PCR. Intestinal tumors were more likely to be B cell than T. The incidence of B and T cell tumors was not different among young (< or = 3 y), middle-aged (> 3 y to < or = 8 y), and old (> 8 y) cats. Both B and T cell tumors from old cats were FeLV-positive more often by PCR than by IHC. Feline leukemia virus DNA but not antigen, was detected in B cell tumors and intestinal tumors from cats > 8 y as often as it was detected in B cell tumors and intestinal tumors from cats < or = 8 y. Previously, most B cell and intestinal tumors from old cats were considered to be negative for FeLV. Here, the results suggest involvement of latent or replication-defective forms of the virus in such tumors from old cats. This study supports a role for FeLV in feline B cell as well as T cell tumorigenesis.
authors.affiliation: Department of Veterinary Pathology, Western College of Veterinary Medicine, Saskatoon, Saskatchewan.
authors.forename: M L
authors.initials: ML
authors.lastname: Jackson
authors.forename: S L
authors.initials: SL
authors.lastname: Wood
authors.forename: V
authors.initials: V
authors.lastname: Misra
authors.forename: D M
authors.initials: DM
authors.lastname: Haines
mesh_terms: D000375:Aging / Q000473:pathology*; D000818:Animals; D000956:Antigens, Viral / Q000032:analysis* / Q000276:immunology; D001402:B-Lymphocytes / Q000276:immunology / Q000473:pathology*; D002371:Cat Diseases / Q000276:immunology / Q000473:pathology*; D002415:Cats; D004279:DNA, Viral / Q000032:analysis / Q000235:genetics; D007150:Immunohistochemistry / Q000379:methods*; D007414:Intestinal Neoplasms / Q000737:chemistry / Q000473:pathology / Q000662:veterinary*; D005256:Leukemia Virus, Feline / Q000235:genetics / Q000276:immunology*; D008228:Lymphoma, Non-Hodgkin / Q000276:immunology / Q000473:pathology / Q000662:veterinary*; D016612:Paraffin Embedding / Q000379:methods / Q000662:veterinary*; D010641:Phenotype; D016133:Polymerase Chain Reaction / Q000379:methods / Q000662:veterinary; D013601:T-Lymphocytes / Q000276:immunology / Q000473:pathology*
chemical_list: D000956:Antigens, Viral; D004279:DNA, Viral