The purpose of this study was to determine concentrations of
IL-2,
IL-10, TGF-β1 in serum and T regulatory cell (Treg) percentage in peripheral blood of dogs with perianal tumours. Investigations were conducted on 32 male dogs of mixed breed. The animals were divided into 4 experimental groups and control group. The groups were established depending on the tumour
malignancy degree and the type of dominant
hormones. All measurements of serum
cytokine concentrations were conducted by the use of commercial diagnostic ELISA kits. Treg lymphocyte percentage was measured by flow cytometry. In both groups with benign tumours
cytokine levels decreased during
therapy, whilst in groups with malignant
tumors, in spite of applying anti-tumour
therapy, concentrations of
cytokines in serum markedly increased. The mean percentage of Treg lymphocytes in dogs with benign tumours (group I and II) was significantly lower than the mean percentage of these cells in control group at all time points, but after applying of anti-hormonal
therapy, the significant increase of Treg percentage was observed compared to baseline values. By contrast, in both groups with malignant tumours (group III and IV), the mean percentage of Treg lymphocytes was significantly higher at the beginning of the experiment comparing with the control group as well as both groups with benign tumours and this percentage increased during anti-tumour
therapy. The results of this study suggest that monitoring changes in
cytokine serum concentrations and Treg percentage in the bloodstream during anti-hormonal
therapy may constitute a subsidiary marker in the monitoring of
therapy effectiveness, in prognosis the outcome of a disease or in differentiating tumour degree of
malignancy.