DEFECTIVE FUNCTIONAL-RESPONSE TO MEMBRANE STIMULI IN LYMPHOCYTES FROMPATIENTS WITH BENIGN PROSTATIC HYPERPLASIA

Benign prostatic hyperplasia (BHP) is a local disturbance in the prost ate that may involve an inflammatory infiltrate predominantly composed of activated lymphocytes and macrophages. The activation and prolifer ative response of T lymphocytes to different mitogenic signals has bee n analysed in peripheral blood mononuclear cells (PMBC) from 45 patien ts with BHP and 55 healthy controls. The PBMC obtained from the patien ts showed a significant specific impairment in proliferation, CD25 exp ression and IL-2 production in response to stimulation with lectins (p hytohaemagglutinin (PHA), concanavalin A (Con A)), that was not correc ted by the addition of IL-2 or of phorbol esters (phorbol myristate ac etate (PMA)). Also, the CD28 response was defective in patient PBMC. A ctivation with anti-CD3 or anti-CD2 MoAbs was normal, but the addition of PMA to these stimuli provoked a significant defective response. On ly the use of transmembrane stimuli (PMA and ionomycin) elicited respo nses similar to those found in the control group. The results indicate that peripheral T lymphocytes from BPH patients show a functional imp airment that is mainly explained by an alteration of membrane signals (PHA, CD28) and is distal to protein kinase C (PKC) activation.