AUA meeting yields dramatic advance in IC research

August 15, 2004

The 2004 AUA annual meeting brought news of the most dramatic advance in the field of interstitial cystitis/painful bladder syndrome over the last 20 years. Researchers reported the complete molecular structure of antiproliferative factor (APF), the peptide produced by bladder epithelial cells only in IC patients.

The 2004 AUA annual meeting brought news of the most dramatic advance in the field of interstitial cystitis/painful bladder syndrome over the last 20 years. Researchers reported the complete molecular structure of antiproliferative factor (APF), the peptide produced by bladder epithelial cells only in IC patients.

In addition to identifying the molecular structure of APF, new findings about pharmacologic and nonpharmacologic treatments highlighted this year's take-home messages about IC, according to Philip M. Hanno, MD, urologist in the department of surgery and medical director in the department of clinical effectiveness and quality assurance at the University of Pennsylvania Health System, Philadelphia.

Researchers have characterized APF from the bladder epithelial cells of patients with interstitial cystitis, hopefully paving the way for urinary levels of APF to be used as a future diagnostic marker.

Dr. Hanno added that the work on APF has been done at a single center, the University of Maryland, Baltimore, by Susan Keay MD, PhD, and her team, and that the next step is to confirm the research elsewhere. (See related article, page 1.)

Amitriptyline (Elavil) appears to be safe and efficacious in reducing pain and urgency symptoms of IC.

Many physicians who treat IC consider amitriptyline to be the most effective oral medication available, and it is one of the two or three most commonly prescribed medications for the condition. Nevertheless, it had never been studied in a controlled way before.

Arndt van Ophoven, MD, and his team in Muenster, Germany, put amitriptyline to the test in a small randomized, placebo-controlled, double-blind trial and demonstrated that the drug works for IC.

The National Institute of Diabetes and Digestive and Kidney Diseases will expand on this study in a large multicenter trial through the Interstitial Cystitis Clinical Research Network to look at the effectiveness of this older generic compound in treatment-naive patients to determine whether it has a place as a primary treatment for IC, Dr. Hanno said. He said the study is just beginning and will likely take 3 or 4 years to complete.

Neuromodulation demonstrates good subjective and objective improvement in 79% of patients with IC followed for an average of 26 months.

A small, single-center study by Craig Comiter, MD, Arizona Health Sciences Center in Tucson, reported on the use of sacral neuromodulation with the InterStim device (Medtronic, Minneapolis) in patients with refractory IC.

Dietary modification, pharmacotherapy, and hydrodistension under anesthesia had all failed for the 27 patients. Among these, the initial test was successful in 19 patients who underwent permanent implantation. At a mean follow-up of 26 months, 15 of the 19 showed sustained improvement.

"So, on an intention-to-treat basis, 55% responded, which is a good percentage for these very difficult-to-treat patients," Dr. Hanno said.

Pain control isn't always reliable with the device, which seems to offer more help with frequency/urgency symptoms.

"Although it's not going to be a miracle, it is going to be an option in the armamentarium that will help some patients," he said.

Subjective pain scores are no different among IC patients receiving instillations of an acid-buffered solution and those receiving a neutral buffered solution. Thus, eliminating acidic foods from IC patients' diets may not be worthwhile.

Few data are available on diet and IC, but diet is used as one of the primary therapies as soon as IC is diagnosed. The most commonly prescribed diet calls for stopping intake of acid foods and beverages and sometimes to use supplements that neutralize the acidity of foods and beverages.