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The Dilemma of Chronic Nonbacterial Prostatitis

Men with pelvic discomfort and unexplained urinary symptoms frequently are diagnosed with chronic prostatitis by primary care physicians and urologists. Although a bacterial cause usually is not identified, many such patients are treated with antibiotics despite the lack of evidence to support this practice (see JW Oct 15 2000, p. 158, accession number 000926001, and Ann Intern Med 2000; 133:367).

To standardize the clinical and research approach to prostatitis, an NIH consensus conference recently developed the following 4 categories (see JAMA 1999; 282:236):

I. acute bacterial prostatitis

II. chronic bacterial prostatitis

III. chronic prostatitis/chronic pelvic pain syndrome

A. inflammatory (leukocytes present in secretions, urine, or semen)

B. noninflammatory

IV. asymptomatic inflammatory prostatitis

Cases belonging to categories I and II have positive urine cultures; cases in category IV are found incidentally when prostate biopsies are done for other reasons. The most common and clinically problematic cases fall into category III.

Results of new studies are shedding some light on chronic nonbacterial prostatitis. Researchers at the University of Washington obtained 3 specimens -- expressed prostatic secretions, postmassage urine, and semen -- from each of 140 symptomatic category III patients. Inflammation (abnormal numbers of leukocytes) was found in 28 percent, 23 percent, and 29 percent of the 3 types of specimens, respectively. Overall, 52 percent of the 140 patients had 1 or more specimens showing inflammation.

In another study, the same researchers used PCR assays to test prostate tissue for bacterial DNA. The prevalence of bacterial DNA was 46 percent in biopsies from 170 patients with chronic prostatitis/pelvic pain and 20 percent in 107 patients with prostate cancer, a significant difference. This finding suggests that bacteria are involved in the pathophysiology of some cases of culture-negative chronic prostatitis.

Another researcher, from the Cleveland Clinic, speculated that some patients with elevated prostate-specific antigen (PSA) levels have category IV prostatitis, thus accounting for false positives in cancer screening. Among 122 asymptomatic men with PSA levels between 4 and 30 ng/mL, expressed prostatic secretions or postmassage urine specimens showed that 51 had inflammation. After 4 weeks of antibiotic therapy, PSA levels normalized in 22 of these patients. During 2 years of follow-up, PSA remained normal in most cases. These patients did not undergo biopsies, however, so it remains possible that some had localized prostate cancer.

These studies do not provide definitive answers to the dilemma of chronic nonbacterial prostatitis. However, they represent a growing body of research that hopefully will lead to effective interventions in the near future.

— AS Brett

Published in Journal Watch General Medicine November 3, 2000

Citation(s):

Krieger JN et al. Does the chronic prostatitis/pelvic pain syndrome differ from nonbacterial prostatitis and prostatodynia? J Urol 2000 Nov 164 1554 -1558.

• Medline abstract (Free)

Krieger JN et al. Bacterial DNA sequences in prostate tissue from patients with prostate cancer and chronic prostatitis. J Urol 2000 Oct 164 1221 -1228.

• Medline abstract (Free)

Potts JM. Prospective identification of National Institutes of Health category IV prostatitis in men with elevated prostate specific antigen. J Urol 2000 Nov 164 1550 -1553.

• Medline abstract (Free)