PSA is a candidate self-antigen in autoimmune chronic prostatitis/chronic pelvic pain syndrome

BACKGROUND. Previous studies demonstrated that recognition of seminal plasm a antigens can occur in patients with chronic prostatitis/chronic pelvic pa in syndrome. This suggests that an autoimmune component may contribute to s ymptoms in some men. To determine if any of the principal secretory protein s of the prostate could be candidate antigens in autoimmune prostatitis, we examined the recall proliferative :response of purified CD4 T cells in pat ients with chronic prostatitis and in normal volunteers using purified semi nal plasma antigens and autologous dendritic cells. METHODS. Peripheral blood mononuclear cells were harvested from 14 patients with chronic prostatitis and 12 normal volunteers by density gradient cent rifugation. The stimulating cells were irradiated autologous dendritic cell s produced by culture of monocyte-enriched fractions with IL-4 and Granuloc yte-Macrophage Colony-Stimulating Factor (GM-CSF). Purified CD4 T cells wer e the responding population. Recall proliferation assays were performed, us ing purified seminal plasma proteins as antigens. RESULTS. In 14 patients with chronic prostatitis, we detected a greater tha n 2-fold increase in proliferative response to PSA compared to control in 5 patients (36%). No response to Prostatic Acid Phosphatase (PAP) or beta-mi croseminoprotein was observed in these 14 patients. In 12 normal volunteer donors with no history of genitourinary disease or symptoms, no proliferati ve response above background was observed for any prostatic antigen. CONCLUSIONS. The data suggest that some men with symptoms of chronic prosta titis have evidence of a proliferative CD4 T-cell response to PSA. PSA is a candidate antigen in chronic prostatitis/chronic pelvic pain syndrome and may be an appropriate target for immunotherapy for prostatic cancer. (C) 20 00 Wiley-Liss, Inc.