Open AccessCanine Lymphoproliferative Disease Characterized by Lymphocytosis: Immunophenotypic Markers of Prognosis
Author(s) -
Williams M.J.,
Avery A.C.,
Lana S.E.,
Hillers K.R.,
Bachand A.M.,
Avery P.R.
Publication year - 2008
Publication title -
journal of veterinary internal medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.356
H-Index - 103
eISSN - 1939-1676
pISSN - 0891-6640
DOI - 10.1111/j.1939-1676.2008.0041.x
Subject(s) - lymphocytosis , immunophenotyping , medicine , lymphoproliferative disorders , immunology , cd8 , pathology , cd34 , flow cytometry , lymphoma , biology , immune system , stem cell , genetics
Background: Canine lymphoproliferative disease often presents with lymphocytosis and is immunophenotypically diverse. Hypothesis: Immunophenotype predicts prognosis in canine lymphoproliferative disorders involving circulating lymphocytosis. Animals: Dogs that had peripheral blood evaluation performed by flow cytometry by the Clinical Immunology Service at Colorado State University between 2003 and 2005. Methods: Outcome data regarding treatment and survival were sought on patients with lymphocytosis comprising a single lymphocyte subset. Ninety‐six patients that met the inclusion criteria had sufficient follow‐up information to be included in the study. Results: Four main phenotypic classifications were found: CD8+ T‐cell, CD21+ B‐cell, CD4‐8‐5+ (aberrant T‐cell phenotype), and CD34+ (undifferentiated progenitor). Expression of CD34 predicted poor outcome with median survival of 16 days ( P < .0001) compared with other phenotypes. Within the CD8+ phenotype, dogs presenting with a lymphocytosis >30,000 lymphocytes/μL had significantly shorter median survival (131 days) than those presenting with <30,000 lymphocytes/μL (1098 days, P < .0008). Within the T‐cell leukemias, there was no difference in outcome between dogs with CD4‐8‐5+ leukemia and dogs with the CD8+ T‐cell phenotype nor was the loss of expression of the pan‐leukocyte marker CD45 associated with decreased survival time. A CD21+ lymphocytosis composed of large cells was associated with shorter survival time (129 days) than those with smaller circulating cells (median survival not reached, P < .01). Conclusions and Clinical Importance: Immunophenotyping provides an objective method for determining prognosis in lymphoproliferative disorders characterized by lymphocytosis.