title: Feline leukemia virus detection by immunohistochemistry and polymerase chain reaction in formalin-fixed, paraffin-embedded tumor tissue from cats with lymphosarcoma.
abstract: The prevalence of feline leukemia virus (FeLV) antigen and DNA was assessed in formalin-fixed, paraffin-embedded tumor tissues from 70 cats with lymphosarcoma (LSA). Tissue sections were tested for FeLV gp70 antigen using avidinbiotin complex (ABC) immunohistochemistry (IHC); DNA was extracted and purified from the same tissue blocks for polymerase chain reaction (PCR) amplification of a 166 base pair region of the FeLV long terminal repeat (LTR). Results were related to antemortem FeLV enzyme-linked immunosorbent assay (ELISA) for serum p27 antigen, anatomic site of LSA, and patient age. Viral DNA was detected by PCR in 80% of cases and viral antigen by IHC in 57% of cases. Seventeen cases were PCR-positive and IHC-negative; one case was PCR-negative and IHC-positive. Clinical records included FeLV ELISA results for 30 of 70 cats. All 19 ELISA-positive cats were positive by PCR and IHC; of the 11 ELISA-negative cats that were negative by IHC, seven were positive by PCR. When evaluated according to anatomic site, FeLV DNA and antigen were detected less frequently in intestinal LSAs than in multicentric and mediastinal tumors. Lymphosarcoma tissues from cats < 7 yr were several fold more likely to be positive for FeLV antigen by IHC than were tumors from cats > or = 7 yr. However, there was no significant difference in PCR detection of FeLV provirus between LSAs from cats < 7 yr and those > or = 7 yr.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Veterinary Microbiology, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon.
authors.forename: M L
authors.initials: ML
authors.lastname: Jackson
authors.forename: D M
authors.initials: DM
authors.lastname: Haines
authors.forename: S M
authors.initials: SM
authors.lastname: Meric
authors.forename: V
authors.initials: V
authors.lastname: Misra
mesh_terms: D000818:Animals; D000956:Antigens, Viral / Q000032:analysis / Q000097:blood; D001483:Base Sequence; D015139:Blotting, Southern; D002371:Cat Diseases / Q000453:epidemiology / Q000382:microbiology*; D002415:Cats; D017931:DNA Primers / Q000737:chemistry; D004279:DNA, Viral / Q000032:analysis; D004797:Enzyme-Linked Immunosorbent Assay; D007150:Immunohistochemistry; D005256:Leukemia Virus, Feline / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification*; D008228:Lymphoma, Non-Hodgkin / Q000382:microbiology / Q000662:veterinary*; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D015995:Prevalence; D012091:Repetitive Sequences, Nucleic Acid; D012192:Retroviridae Infections / Q000453:epidemiology / Q000382:microbiology / Q000662:veterinary*; D012689:Sequence Homology, Nucleic Acid; D014412:Tumor Virus Infections / Q000453:epidemiology / Q000382:microbiology / Q000662:veterinary*
chemical_list: D000956:Antigens, Viral; D017931:DNA Primers; D004279:DNA, Viral