Pentosan polysulfate and a pigmentary maculopathy: causation versus correlation?

Interstitial cystitis (IC) is a chronic disease with urinary tract symptoms and pain. Pentosan polysulfate (PPS) is the only U.S. Food and Drug Administration approved oral medication for the treatment of IC pain and symptoms. Recently, articles described a pigmentary maculopathy in IC patients on long term PPS therapy. Currently, there is no definitive study directly linking PPS as the cause of the pigmentary maculopathy. The aim of this review is to evaluate if PPS is the causative factor of the pigmentary maculopathy or if PPS use is only associated with the pigmentary maculopathy.

A comprehensive review of peer reviewed journals using the search terms IC, maculopathy, mast cells, immune inflammatory components, Tamm-Horsfall protein, cations and tight junctions was performed to examine the pathophysiology and role of chronic inflammation in IC and known retinal maculopathies.

Chronic inflammatory cells have been reported in age-related macular degeneration choroid blood vessels and in bladder submucosal and detrusor layers in IC patients. Studies in IC and maculopathies demonstrate a significant milieu of activated chronic inflammatory and immunologic responses that cause a more "leaky" epithelium and a subsequent cascade of inflammatory events that results in the pathological changes seen in these two conditions.

After an analysis of the literature describing a pigmentary maculopathy in IC patients on long term PPS, a causal relationship does not appear to be present. An alternate model is proposed postulating that the causative factor for the pigmentary maculopathy is the underlying inflammatory state associated with IC and not PPS use.