Dr. Nir Modiano (modiano@ohsu.edu) from OHSU, is looking to collaborate with a chemist or toxicologist on an effort to understand whether the therapeutic PPS may contribute to inflammatory bowel disease.

“Briefly, PPS is a sulfated polysaccharide that is used as a therapy for interstitial cystitis.  We have found that a few of our IBD patients on PPS improved after stopping the PPS.  In the 1990’s studies of high-dose PPS use for bladder cancer were dose-limited by proctitis, supporting the notion that it could be a causative agent in colitis.  We then noticed a number of patients on it developed multifocal dysplasia, requiring colectomy to prevent progression to malignancy.  Since the number of patients taking PPS is fairly small, we collaborated with Stanford and identified 30 patients with IBD who had been on PPS for >2 years (arbitrarily chosen because we did not want to include patients who had minimal exposure).  Of these, 1 in 3 developed multifocal dysplasia as of time of our study, which is a very high number.  We think this case series supports the hypothesis that PPS may increase the risk of both IBD and colonic dysplasia, though obviously, a small case series is not a definitive study.     

Of note, PPS may share similiarities in chemical structure with DSS, and both are sulfated polysaccharides, though we have not yet had a chemist or toxicologist weigh in on whether the similarities are likely to be relevant.  We’d be interested in gaining perspective from someone with relevant experience in toxicology to help us understand our observations and, perhaps, collaborate on research related to these findings.  One reason I find this so interesting is that it may offer insight into other environmental exposures that may be contributing to the rapid increase in IBD cases we are seeing in the western world, and perhaps, the increased rates of colorectal cancer at younger ages.”