Lymphocyte immunophenotype in dogs with immune-mediated hematologic disease
Shauna L Blois1, Benoît Y Cuq2, Dorothee Bienzle2
1Department of Clinical Studies, Ontario Veterinary College, University of Guelph, Guelph, Ontario, Canada.
Plos One
|June 17, 2025
Summary
Immune-mediated hematologic diseases in dogs show altered immune cell levels, specifically fewer T regulatory cells and more IL-17+ lymphocytes. These findings shed light on the immune system
Area of Science:
- Veterinary Immunology
- Canine Hematology
- Immunopathology
Background:
- Immune-mediated hematologic diseases (IMHD) like immune-mediated hemolytic anemia (IMHA) and immune thrombocytopenia (ITP) cause severe illness in dogs.
- The specific immune system abnormalities underlying IMHD remain largely unknown.
Purpose of the Study:
- To investigate immune system alterations in dogs with IMHD.
- To test the hypotheses that IMHD dogs have increased CD4+, CD8+, and IL-17+ lymphocytes, and decreased T regulatory cells.
Main Methods:
- Prospective study of 15 dogs with newly diagnosed IMHA or ITP and 15 healthy controls.
- Flow cytometry used to quantify CD4+, CD8+, T regulatory (CD4+CD25+Foxp3+), and IL-17+ lymphocytes.
- Analysis performed at diagnosis and 2 and 4 days post-immunosuppressive treatment initiation.
Main Results:
- Dogs with IMHD had significantly lower proportions of CD4+ and CD8+ lymphocytes compared to controls.
- A deficiency in T regulatory cells was observed in IMHD dogs at diagnosis.
- An increased proportion of IL-17+ lymphocytes was found in IMHD dogs at Day 2 of treatment.
Conclusions:
- Dogs with IMHD exhibit distinct immune system alterations at diagnosis, including T regulatory cell deficiency.
- An increase in IL-17+ lymphocytes occurs during early treatment, suggesting a role in IMHD pathogenesis.
- These immune dysregulations may contribute to the development of IMHA and ITP in dogs.
