Prevalence and significance of prostatic inflammation

Prostatic fluid specimens were collected by digital massage from 325 consecutive men. White blood cells per high power microscopic field were counted under a cover slip. Lactate dehydrogenase isoenzymes in the fluid were separated by acrylamide disk electrophoresis and the ratio of lactate dehydrogenase-5/lactate dehydrogenase-1 was used as a parameter of epithelial cellular damage. Diagnoses were based on history, physical examination, and urine and fluid cultures, irrespective of the prostatic fluid white blood cells per high power field and lactate dehydrogenase-5/lactate dehydrogenase-1. The prostatic fluid of 31 patients with no urologic disease had 0.7 ± 0.41 white blood cells per high power field (mean ± standard error); 30 (97 per cent) of the specimens had less than 2 white blood cells per high power field. The prostatic fluid of 88 patients with non-inflammatory urologic disease had 3.8 ± 0.83 white blood cells per high power field; 76 (86 per cent) of the specimens had less than 10 white blood cells per high power field. The lactate dehydrogenase-5/lactate dehydrogenase-1 ratios for these groups were 0.9 ± 0.21 and 1.6 ± 0.32, respectively. Eighteen infertile patients had a mean prostatic fluid white blood cell count (8.3 ± 2.43) significantly higher than controls with no urologic disease (p less than 0.01). The lactate dehydrogenase isoenzyme ratio was not elevated. Patients with bacterial prostatitis had significantly higher prostatic fluid white blood cell counts (79.4 ± 13.5) and lactate dehydrogenase-5/lactate dehydrogenase-1 ratios (7.7 ± 2.87) than controls (p less than 0.001). Of the 35 patients with abacterial prostatitis (10 or more white blood cells per high power field) 13 (37 per cent) were asymptomatic. The white blood cell counts in prostatic fluid from patients with irritative voiding symptoms (38.8 ± 7.10) or prostatic obstructive symptoms (13.6 ± 2.07) differed significantly from the value in patients with prostatic pain (4.0 ± 1.19) (p less than 0.001). The data suggest that white blood cells and high lactate dehydrogenase-5/lactate dehydrogenase-1 ratios are present rarely in normal prostatic fluid and that elevated white blood cell and lactate dehydrogenase-5/lactate dehydrogenase-1 values frequently are associated with clinically significant disorders.