[Analysis of lymphocyte subpopulations of the bladder following endovesical immunotherapy using BCG]

The authors studied, by means of immunohistochemical analyses, the lymphocyte subpopulations in bladder biopsies from 20 patients treated for a urothelial bladder tumour (Tis TA, T1) by intravesical BCG (group A). The biopsies were taken from optically healthy zones and were then frozen. The lymphocyte populations in the urothelium and chorion were studied by means of monoclonal antibodies T3, T4, T8, TQ1, Leu-7, OKM-1, HLA-DR, TAC, Pan-B. Four patients without bladder cancer constituted the control group (group B) and 10 patients with bladder cancer not treated by intravesical BCG constituted group C. In group A, the T4 + TQ1 lymphocytes predominated in the urothelium and in the chorion. An inversion of the T4/T8 ratio was observed in the urothelium of groups B and C (p less than 0.01) and in the chorion of group B (p less than 0.01). There was no significant difference in the T4/T8 ratio in the chorion in groups A and C. In group A, 17 patients expressed the presence of receptors for interleukin 2 (TAC + HLA-DR) on their T lymphocytes. In these cases, the lymphocytic infiltration was associated with the presence of eosinophils (p less than 0.05) and the total absence of NK cells was observed. No B lymphocytes were detected, apart from a few rare lymphoid follicles.