Gallbladder polyps in patients receiving subcutaneous treprostinil therapy for Pulmonary Arterial Hypertension

Title: Gallbladder polyps in patients receiving subcutaneous treprostinil therapy for Pulmonary Arterial Hypertension
Author(s): S Cullivan, N Boyle, B McCullagh, SP Gaine
Institution: Mater Misericordiae University Hospital
Poster: Click to view poster
Category: General Respiratory and Sleep
Abstract: Idiopathic pulmonary arterial hypertension (IPAH) is a devastating illness characterised by progressive pulmonary vascular remodelling, proliferation and obliteration. Prostacyclin therapy is a core component of treatment, as it exerts beneficial pulmonary vasodilatory, antiproliferative, anti-inflammatory and antiplatelet properties. Interestingly prostacyclin analogues are not specific for the prostacyclin (IP) receptor and bind additional prostanoid receptors; this is exemplified by treprostinil, which mediates its physiological effects via a combination of IP, prostaglandin E2 (EP2) and prostaglandin D1 receptors (1). Outside of the pulmonary vasculature, prostacyclin has diverse functions including a recognised role in gallbladder physiology (2).

In our centre, a total of 50 patients are currently prescribed exogenous prostacyclin therapy for pulmonary hypertension and 8 have recent gallbladder imaging. Gallbladder polyps were identified in 3 of these 8 cases (37.5%) and all of these received prolonged treprostinil (Remodulin) therapy (Table 1). These results are higher than anticipated, as studies have reported gallbladder polyp prevalence between 1.4 - 12% in the general population.

We describe three cases of incidental gallbladder polyps in patients with IPAH and hypothesize that treprostinil may be implicated in the formation of these gallbladder polyps, due to its specific effects on IP and EP2 receptors and the established role of prostanoids in gallbladder health and disease.