Measurement of nitric oxide may differentiate between inflammatory and non-inflammatory prostatitis

The majority of patients with prostatitis have chronic non-bacterial prostatitis/chronic pelvic pain syndrome of inflammatory type (Category IIIA) or non-inflammatory type (Category IIIB), based on the National Institutes of Health classification. The aim of this study was to investigate whether measurement of nitric oxide (NO) formation in the prostatic urethra can be used as a marker for inflammation in the evaluation of patients with chronic prostatitis/pelvic pain syndrome.

A total of 25 men with prostatitis were examined. In 8 patients >10 white blood cells/high-power field (WBC/hpf) were found in expressed prostatic secretion (EPS) (Category IIIA), whereas the other 17 had no signs of inflammation (Category IIIB). NO production was measured using a silicon catheter, with the catheter balloon being placed in the prostatic urethra. Room air (5 ml) was incubated for 5 min and analyzed. NO formation in the urinary bladder was also measured.

The NO concentration in the prostatic urethra was significantly higher in the 8 patients with >10 WBC/hpf than in those with <10 WBC/hpf. The NO concentration in the urinary bladder was low in both groups.

We found an elevated NO concentration in the prostatic urethra in patients with >10 WBC/hpf in the EPS but not in those with <10 WBC/hpf, which supports the theory of different pathogeneses for Categories IIIA and IIIB. Measurement of NO production in the prostatic urethra can be used to discriminate between the two categories and as the method is easy and fast it may represent an attractive alternative to the four-glass test.