May 11, 2001

Vanderbilt researchers discover potential link between C. pneumoniae and Interstitial Cystitis

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Dr. Denis O'Day

Vanderbilt researchers discover potential link between C. pneumoniae and Interstitial Cystitis

Researchers at Vanderbilt University Medical Center have discovered a potential role of Chlamydia pneumoniae (C. pneumoniae) in the pathogenesis of Interstitial Cystitis (IC).

Interstitial Cystitis is a syndrome characterized by urinary frequency, urgency, nocturia, and pain with bladder filling. Some patients have significant bladder inflammation, and a few have ulcers, scarring and stiffening.

Diagnosis is based on symptom, findings on cystoscopy and biopsy, and elimination of other treatable causes, such as infection. Because doctors do not know what causes IC, treatments are aimed at relieving symptoms.

The C. pneumoniae organism, first described in 1988, is an airborne organism that you get from breathing after a person carrying the organism has coughed. As an obligate intracellular parasite, it is difficult to detect by routine cultures, can cause chronic infections, and may not elicit an acute inflammatory response. C. pneumoniae is commonly associated with respiratory tract infection, but has also been implicated in the development of coronary artery plaques.

The data using polymerase chain reaction (PCR) analysis of urine revealed that 81 percent of patients with IC and 16 percent of controls were positive for C. pneumoniae, suggesting a potential role for this organism in the development of IC.

Seventeen patients with IC as outlined by NIADDK criteria and six control patients underwent bladder biopsy. Selection of control patients was limited to those patients without history of irritative voiding systems, transitional cell carcinoma or recurrent urinary tract infection. Biopsy specimens were analyzed for C. pneumoniae using standard tissue culture technique. Of those patients with IC, 82 percent (14/17) had tissue culture positive for C. pneumoniae. In control patients, 16 percent (1/6) had tissue cultures positive for C. pneumoniae.

“We found a statistically significant correlation between IC and infection with C. pneumoniae based on tissue culture,” said Dr. Jenny J. Franke, assistant professor of Urologic Surgery at Vanderbilt. “These results also parallel those obtained with urine PCR. The possible role of C. pneumoniae in the pathogenesis of IC remains to be determined by further analysis of tissue culture results as well as monitoring patient response to appropriate antimicrobial therapy.”

The Vanderbilt researchers will present their data at the American Urological Association’s 2001 Annual Meeting in Anaheim, Ca., June 2-7 to encourage further investigation of the association between C. pneumoniae and IC.

The study of the organism has intensified as Vanderbilt and other medical centers around the country, including Johns Hopkins and The Mayo Clinic, look at the role of chlamydia in diseases such as multiple sclerosis, rheumatoid arthritis, pyoderma gangrenosum, coronary artery disease and interstitial cystitis.

The Vanderbilt researchers include Drs. Gregory L. Alberts, Charles W. Stratton, William M. Mitchell, and Jenny J. Franke. Funding for the research was provided through the Interstitial Cystitis Association.