Damon Runyon Cancer Research Fellow Columbia University New York, New York, United States
Abstract:
Background: Immune-mediated hemolytic anemia (IMHA) is caused by autoimmune destruction of erythrocytes, resulting in severe morbidity. Most dogs are treated with corticosteroids, but few clinical tools exist to predict which dogs will respond to treatment or experience treatment-related adverse effects. Hypothesis/
Objectives: To evaluate novel biomarkers of treatment response and corticosteroid adverse effects in dogs with IMHA. Animals: Thirty-one client-owned dogs with non-associative IMHA, evaluated at diagnosis, 5 days, and 2 weeks after onset of treatment with prednisolone and azathioprine.
Methods: Residual blood samples were stimulated with phorbol 12-myristate 13-acetate and ionomycin before total RNA was extracted for quantitative reverse transcription (qRT)-PCR reactions to measure expression of the cytokine genes Il2, Il4, Il10, Il17, and Ifng. Linear regression models were created to evaluate associations between gene expression and clinical outcome variables, including quality-of-life parameters from a validated questionnaire and direct measurement of water intake, blood pressure, and 6-minute walk test.
Results: All cytokine genes were detectable in stimulated blood at diagnosis, with Il10 expression increasing significantly after onset of treatment (p=0.03), whereas Il17 decreased (p=0.049). However, expression of Il10 or Il17 was not associated with packed cell volume at 14 days after diagnosis or duration of hospitalization. Higher Il2 expression after starting treatment was a significant predictor of greater water intake measured 2 weeks after diagnosis (p=0.0045), but no other associations were detected between gene expression and quality-of-life parameters. Conclusions and Clinical Importance: Expression of cytokine genes, at diagnosis or upon treatment, could represent helpful biomarkers for corticosteroid-related adverse effects.
