Transferrin Receptor Expression in Canine Lymphoma

Transferrin receptor 1 (TfR1) expression was measured by immunohistochemistry in 78 archived cases of canine B-cell and T-cell lymphoma with an anti-human TfR1 monoclonal antibody that was validated in the dog by immunohistochemistry and immunoblotting. The canine lymphoma cases were initially classified on the basis of World Health Organization criteria and then subdivided into the following 4 subgroups: low-grade B-cell (LGB), high-grade B-cell (HGB), low-grade T-cell (LGT), and high-grade T-cell (HGT). A visual scoring system and densitometric analysis of the proportion and intensity of positive staining were used to quantify TfR1 expression. TfR1 expression was also correlated to mitotic rate. TfR1 expression was significantly lower in the LGT tumors compared to all other lymphoma subgroups (LGB, HGB, and HGT). LGB tumors showed a TfR1 expression similar to those of the high-grade tumors (HGB and HGT). Significant correlations were found between mitotic rate and densitometric TfR1 variables in the T-c...