An immunohistological study of granulomatous prostatitis.

Granulomatous prostatitis may result from tuberculosis and fungal infection and has been described following prostatic surgery. In most cases, however, the aetiology is unknown, although it may be due to a reaction to extravasated or altered prostatic secretions. We have investigated cells (macrophages, lymphocytes), serum proteins (fibrinogen, alpha 1-antitrypsin) and prostatic epithelial products (prostatic-specific antigen and prostatic acid phosphatase) in diffuse granulomatous prostatitis (3 cases), focal periacinar prostatic granulomas (9) and focal prostatic infarcts (5), using an immunohistological technique. T-lymphocytes and macrophages are present in diffuse and focal granulomatous prostatitis, but few B-lymphocytes occur. Fibrinogen-related antigen is absent from granulomas, but a small amount is present within infarcts, whereas plentiful alpha 1-antitrypsin was detected both in granulomas and infarcts. Significant reduction in prostatic-specific antigen and acid phosphatase reactivity occurs in granulomatous prostatitis. This suggests that cytokines derived from activated macrophages and T-lymphocytes may be exerting a cell regulatory effect and altering cell secretions, as well as causing destruction of the prostatic epithelium.