• bladder cancer;
  • bacillus Calmette-Guerin;
  • systemic immunity;
  • peripheral blood lymphocyte subsets

Background: Intravesical bacillus Calmette-Guérin (BCC) therapy for superficial bladder cancer induces obvious local immunological responses. The purpose of this study was to examine the systemic immunological influences induced by intravesical BCG therapy.

Methods: We measured peripheral blood lymphocyte subsets (PBLS) and monocyte counts in 30 patients with superficial bladder carcinoma by two-colored flow cytometry before, during, and after intravesical BCG treatment. Comparisons were made between 24 good treatment responders and 6 poor responders.

Results: From 3 to 12 months after the beginning of treatment, PBLS and monocyte counts changed, as evidenced by an increase of suppressor T cells and a decrease of helper T cells. The good responders had higher cell counts than the poor responders, with differences in cell counts between good and poor responders more marked 1 month after beginning treatment, particularly of natural killer cells, cytotoxic T cells, and inducer T cells. These differences disappeared 3 months after the onset of treatment.

Conclusion: Intravesical BCG therapy caused a marked and persistent alteration of the systemic immunological status.