PHENOTYPE AND FUNCTION OF PERIPHERAL AND PROSTATIC LYMPHOCYTES IN PATIENTS WITH BENIGN PROSTATIC HYPERPLASIA

In a previous report, we demonstrated intense lymphocytic infiltration of all benign prostatic hypertrophy (BPH) tissues analyzed in conjunc tion with HLA-DR expression on normally MHC-class-II-negative prostate epithelial cells. The composition of these infiltrates (70 to 80% CD3 + T-cells, but no granulocytes) resembles the situation seen in immune responses against altered self or self rather than against foreign an tigens (infection). In the present study, phenotypic and functional im munoassays were used in order to investigate whether T-cells in BPH ar e indeed activated, and whether this activation is systemic or restric ted locally to the prostate. Analysis of T-cell activation marker expr ession and proliferation requirements provided substantial evidence th at these infiltrating lymphocytes, in contrast to their peripheral cou nterparts, are chronically activated. Since local accumulation of acti vated lymphocytes can cause tissue destruction, high concentrations of cytokines, and consequently tissue rebuilding, this process might con tribute to the pathogenesis of BPH.