Interstitial cystitis (IC) is a disease that causes painful inflammation of the bladder that affects more than 1 million Americans, 90 percent of them women. It causes frequent urination, sometimes up to 60 times a day, and chronic pain. No one knows what causes the disorder—it is diagnosed when every other possible cause has been ruled out—and there is no cure. A group of scientists at the University of Maryland medical school identified a toxin that is found in the urine of 95 percent of IC patients and in no patients without the disease. As they have continued to study the toxin, called an antiproliferative factor (APF), they are getting closer to a diagnosis, and a cure, for this disease.

What the scientists wanted to know: What does this antiproliferative factor look like, how does it act in the bladder, and how could understanding it be used to diagnose and cure interstitial cystitis?

What they did: The scientists extracted bladder tissue from six patients with IC and six patients without any urinary tract problems. They isolated this APF and examined its properties through a variety of laboratory procedures and tests. They used their observations to make a synthetic version of the toxin.

What they found: This APF turns out to be a previously unknown member of a group of proteins that has also been associated with a type of heart failure and retinal degeneration. The researchers worked out the chemical structure of the protein and learned that it inhibits the growth of the cells in the lining of the bladder. Based on those findings, and the fact that it is seen only in people with IC, they believe it is likely one of the causes of the disease. By creating a synthetic version of the APF, they were able confirm its chemical structure and create large-enough quantities to develop tools for recognizing the toxin that could possibly be used to diagnose the disease.

What it means to you: For people who suffer from IC, this study offers hope that a solid diagnosis and treatment may not be far off. Because they have identified the toxin, the APF, which the scientists believe inhibits the bladder's natural cell production, they may soon be able to control the toxin, reducing the pain, and possibly restoring the function of the bladder.

Caveats: This study is a scientific description of a type of protein; it is not a clinical trial, which has a much more practical and immediate effect on the treatment of a disease. This study may spur new drugs into development, but it would be years before they reached the market.

Find out more: The Interstitial Cystitis Network has resources for patients, message boards, answers to questions, and information about clinical trials.

Read the article: Keay, S.K. "An Antiproliferative Factor From Interstitial Cystitis Patients Is a Frizzled 8 Protein-Related Sialoglycopeptide." Proceedings of the National Academy of Sciences. Aug. 10, 2004, Vol. 101, No. 32, pp. 11803–11808.

Abstract online: www.pnas.org