Immunocytological analysis of leukocyte subpopulations in urine specimens before and after prostatic massage.

Objective: To evaluate the presence of leukocyte subpopulations in urine after prostatic massage (VB 3) in symptomatic patients with > or =10 leukocytes/high power field (magnification x1,000) in expressed prostatic secretions, and who were classified as suffering from chronic bacterial prostatitis or inflammatory chronic pelvic pain syndrome.

Methods: 115 consecutive patients were investigated. Granulocytes in centrifuged midstream urine (VB 2) and VB 3 were counted after Papanicolaou stain. Macrophages, B and T lymphocytes were analyzed after immunocytological staining with monoclonal antibodies according to the alkaline phosphatase anti-alkaline phosphatase method. The counts were quantified as the number of cells per view field at a magnification of x400. In all patients, acute or chronic urethritis had been excluded before enrollment in the study. 16 men without signs or symptoms of urogenital inflammation served as controls.

Results: Of the 115 patients, 101 men demonstrated > or =10 leukocytes/view field in VB 3. In comparison to VB 2, the leukocyte subpopulations in VB 3 demonstrated an increase in granulocytes (9.2-fold), macrophages (7.6-fold), T lymphocytes (7.6-fold), and B lymphocytes (4-fold). The increase was statistically significant (p<0.001 each). The proportion of these cells in VB 3 was 81.6, 11.1, 5.5, and 1.8%, respectively. As compared to controls, all leukocyte subsets in VB 3 were significantly elevated (p>0.001 each).

Conclusion: Elevated numbers of leukocytes in VB 3 are indicative of prostatitis provided that urethral inflammation and leukocyturia in VB 2 are excluded. Granulocytes are the predominant cell type of inflammation. The increase in macrophages, T and B lymphocytes in prostatic secretions indicate the participation of both the cellular and humoral immune system in the inflammatory process.