Expression of T cell FOXP3 and Helios, and tumor cell MHC class II, all impact prognosis in dogs with B cell lymphoma.

<p>The frequency of FOXP3⁺ cells within the ‘All’ gate (A), or within a cascaded All→CD5⁺→CD4⁺ gate (B), influenced survival times. Overall survival times were shorter in those dogs with frequencies of FOXP3⁺ T cells higher than the median value (A: p = 0.02); a similar pattern in progression-free survival (PFS) was observed (B: p = 0.01). The frequency of Helios⁺ cells within the ‘All’ gate also influenced PFS (C: p = 0.01). The intensity of MHC class II expression by the lymphoma cells, expressed as the ratio of geometric mean fluorescence intensity of MHC II⁺:MHC II⁻ cells within the CD5⁻ subset of the ‘All’ gate, was also of prognostic significance: time to remission was longer in those cases with less MHC class II expression per cell (D: p = 0.02).