Introduction

Overexpression of CD25, the alpha chain of the IL2 receptor, has been associated with poor prognosis in humans with diffuse large B cell lymphoma (DLBCL). Limited data in dogs with DLBCL has been reported, with similar findings. The objective of this study was to evaluate CD25 expression as a prognostic indicator in dogs with BCL diagnosed with noninvasive diagnostics (cytology and flow cytometry) and treated with CHOP-based chemotherapy.

Methods

This was a retrospective study of 57 client-owned dogs with BCL treated with CHOP. Lymph node aspirates from dogs with a cytologic diagnosis of lymphoma comprised of intermediate to large lymphocytes were analyzed with flow cytometry. Percentage of neoplastic B cells expressing CD25 and median fluorescence intensity (MFI) of CD25 were measured. Relationships of CD25 positivity and MFI with PFI and MST were evaluated along with other prognostic factors.

Results

Overall MST was 272 days (95% CI, 195–348) and median PFI was 196 days (95% CI, 171–220). High percentage of CD25 positivity (n=31 dogs) was associated with longer survival time (318 versus 176 days), which was significant in multivariable analysis (p=0.012). Dogs with high CD25 MFI (n=21) had a longer PFI (218 versus 140 days) although this was not significant (p=0.056).

Conclusion

High CD25 expression was associated with longer survival time in dogs with BCL treated with CHOP. Additional prospective studies are needed to better understand the relationship of CD25 expression with outcome in dogs diagnosed with BCL using cytology and flow cytometry.

Funding Information

None.