Title | Immunophenotypic characterization and clinical outcome in cats with lymphocytosis. |
Publication Type | Journal Article |
Year of Publication | 2020 |
Authors | Rout, ED, Labadie, JD, Curran, KM, Yoshimoto, JA, Avery, AC, Avery, PR |
Journal | J Vet Intern Med |
Volume | 34 |
Issue | 1 |
Pagination | 105-116 |
Date Published | 2020 Jan |
ISSN | 1939-1676 |
Keywords | Animals, B-Lymphocyte Subsets, Cat Diseases, Cats, Female, Flow Cytometry, Lymphocytosis, Male, Retrospective Studies, T-Lymphocyte Subsets |
Abstract | BACKGROUND: Lymphocytosis is relatively common in cats, but few studies describe lymphocyte populations or the clinical course associated with different immunophenotypic expansions. HYPOTHESIS/OBJECTIVES: We hypothesized that cats frequently develop non-neoplastic lymphocytosis and that different neoplastic immunophenotypes have variable prognoses. We aimed to characterize the lymphocyte expansions in a large population of cats with lymphocytosis and to assess clinical presentation and outcome in a subset. ANIMALS: Three cohorts of cats older than 1 year with lymphocytosis (>6000/μL) were examined to define immunophenotypic categories (n = 146), evaluate outcome (n = 94), and determine prevalence of immunophenotypes (n = 350). METHODS: Retrospective study of cats with blood submitted for flow cytometry. Medical records (n = 94) were reviewed for clinical data, treatment, and survival information. RESULTS: Five major immunophenotypic categories were identified: B cell, heterogeneous (≥2 lineages expanded), CD4+ T cell, CD4-CD8- (double negative [DN]) T cell, and CD5-low-expressing T cell. B-cell and heterogeneous phenotypes were more consistent with a non-neoplastic process, having polyclonal antigen receptor gene rearrangements, younger age at presentation, lower lymphocyte counts, and prolonged survival. The neoplastic phenotypes, CD4+ T cell, DN T cell, and CD5 low T cell, had different median survival times (752 days [n = 37], 271 days [n = 7], 27.5 days [n = 12], respectively). Among CD4+ T-cell cases, cats with abdominal lymphadenopathy, intestinal involvement, or both and females had shorter survival. Among 350 cats with lymphocytosis, CD4+ T-cell lymphocytosis was most common, followed by heterogeneous and B-cell phenotypes. CONCLUSIONS AND CLINICAL IMPORTANCE: Neoplastic CD4+ T-cell lymphocytosis is common in cats and has a prolonged clinical course compared to aberrant T-cell phenotypes. Cats with heterogeneous and B-cell lymphocyte expansions commonly have non-neoplastic disease. |
DOI | 10.1111/jvim.15650 |
Alternate Journal | J Vet Intern Med |
PubMed ID | 31693230 |
PubMed Central ID | PMC6979106 |
Grant List | K05 CA152715 / CA / NCI NIH HHS / United States T32 CA094880 / CA / NCI NIH HHS / United States D08FE-008 / / Morris Animal Foundation / |