Objectives: This paper studies the phenotypical characteristics of the lymphocytes present in mononuclear cell (MNC) preparations from peripheral blood (PBMNC), lymph nodes (LNMNC), tumor bladder (TBMNC), and tumor-free bladder (TFBMNC) from patients with infiltrated transitional cell carcinoma (TCC) of the bladder and PBMNC of healthy controls.
Methods: Eight patients diagnosed with TCC of the bladder, according to UICC criteria, and 10 healthy controls were studied. For immunofluorescence staining, T lymphocytes were incubated with combinations of fluorescein (FITC, green)- and phycoerytrin (PE, red)-labelled monoclonal antibodies.
Results: The percentage of NK cells in the LNMNC and TFBMNC was significantly decreased in comparison to that found in the PBMNC from these patients (p < 0.05). A significant enhancement of the expression of class II molecules of the major histocompatibility complex (MHC) by CD3+ T lymphocytes from TBMNC and TFBMNC specimens from bladder walls was found with respect to those quantified in CD3+ T lymphocytes from PBMNC (p < 0.05). In addition, the percentage of CD3+CD25+ T lymphocytes was significantly higher in PBMNC in TCC patients than in healthy controls (p < 0.05).
Conclusions: Our data clearly demonstrate that the presence of infiltrative TCC of the bladder is associated to an infiltration of in vivo activated T lymphocytes of the urinary bladder wall. This in vivo T lymphocyte activation has been considered an expression of the immune response against the tumor cells.