Dendritic cells in blood and urine samples from bladder cancer patients undergoing BCG immunotherapy

Objectives: Immunotherapy with BCG (Bacille Calmette-Guérin) after transurethral resection of the bladder tumor represents a highly effective primary treatment for intermediate and high-risk superficial bladder cancer. The effectiveness of this therapy has been documented, but its mechanism of action is not clear yet. In the present study, we investigated the changes of dendritic cells (DC) numbers in peripheral blood and urine of patients with superficial bladder cancer undergoing BCG intravescical therapy Material and method: We have enumerated plasmacytoid and myeloid DCs in the peripheral blood and in the urine of patients with bladder cancer in order to clarify the role of these cells in the evolution of the disease and the effect of therapy. DCs in blood and urine samples were assessed using the single-platform TruCOUNT assay with monoclonal antibodies. The study population included 37 healthy donors and 13 patients with diagnosis of primitive superficial bladder cancer. Results: At the time of diagnosis a reduction of blood DCs was found in patients as opposed to healthy donors, while DCs were not found in the urine in the same way as in healthy subjects. Six of these patients were followed before and after weekly and monthly instillations of BCG. In the peripheral blood, we observed an immunological recovery of DCs from the third weekly instillation up to the sixth. In the urine of patients, we didn’t find mDCs or pDCs at T0, but we found a statistically significant change from the third instillation up to the sixth. On the contrary, we didn’t find mDCs in urine during monthly instillation. Conclusions: DC Count could be used in the monitoring of patients undergoing BCG therapy. Immunological restoration of mDC numbers in peripheral blood and the efflux in urine could be important for confirming the effectiveness of BCG instillation.