The pain can be persistent, agonizing -- and not something that many sufferers want to discuss.
Interstitial cystitis, a chronic inflammation of the bladder wall, causes symptoms similar to those of an acute urinary tract infection with severe urgency and frequency of urination, sometimes as often as 50 or 60 times a day, and burning pelvic pain.
It afflicts nearly 1 million Americans, 90% of whom are women. Although several treatments exist, they fail to provide relief for about 40% of sufferers, says Dr. Kenneth M. Peters, a urologist at William Beaumont Hospital in Royal Oak, Mich.
But he's found something that may help.
Peters has pioneered use of Bacillus Calmette-Guerin, a weakened form of the bug that causes tuberculosis.
By boosting immune response, the bacterium seems to relieve the pelvic pain and frequent urination that are hallmarks of the condition.
"It's a promising therapy and may be a viable option for people who have no alternatives," says Dr. Kristine E. Whitmore, a urologist and director of the Pelvic Floor Institute at General Hospital in Philadelphia.
Scientists don't know what causes interstitial cystitis but they speculate that chemicals in the urine may penetrate the bladder's lining, causing irritation inside the bladder wall. An overproduction of certain immune cells known as cytokines may also prompt the chronic inflammation.
The use of Bacillus Calmette-Guerin as a vaccine for tuberculosis and as a treatment for superficial bladder cancer appears to correct this imbalance by prompting the immune system to produce cells that neutralize the effects of these cytokines.
In a 1998 study, 30 treatment-resistant sufferers were given six weekly bladder washes of either water or a liquid form of the bacterium.
At the end of six months, 60% of patients who received the bacterium wash had marked improvements in symptoms, including a dramatic decrease in pain and daytime voiding, and an upswing in quality of life.
Only 27% of those in the placebo group had a response.
The placebo patients were then treated with the bacterium wash and 67% improved.
In addition, 89% of the patients who responded to the therapy maintained improvement for two years without further treatment.
"This truly improves symptoms -- the ones who got better got significantly better," says Peters, who conducted the study.
Based on those results, the National Institutes of Health sponsored a test of the bacterium on 260 interstitial cystitis patients at 10 sites around the country, the results of which should be available in the fall.
The bacterium is currently approved by the U.S. Food and Drug Administration to treat bladder cancer, but insurers normally don't pay for unapproved uses.
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Treatments for interstitial cystitis
Interstitial cystitis is treated with a combination of diet, drugs and bladder washes.
Avoiding acidic foods and beverages such as coffee, tea and carbonated and alcoholic drinks can reduce the severity of symptoms. Elmiron (pentosan polysulfate sodium) can ease discomfort and pain by restoring the thin or leaky bladder surface. Antihistamines such as Atarax and Vistaril are used to stop the immune reaction that seems to play a role in triggering the condition.
Pain relievers, such as Vicodin and Percocet, as well as tricyclic antidepressants, such as Elavil, can reduce pain. DMSO (dimethyl sulfoxide) is used as an anti-inflammatory bladder wash.
Tests are also underway for another experimental therapy, RTX (resiniferatoxin), a bladder wash that seems to work by deadening the nerve fibers in the bladder. Preliminary research suggests it alleviates bladder pain as well as urgency and frequency of urination.