Idiopathic portal hypertension with regard to thiopurine treatment

Idiopathic portal hypertension (IPH) is an infrequent adverse reaction to the use of thiopurines that tends to be overlooked. Herein, we present a patient with ileocolic Crohn's disease treated with azathioprine who presented ascites, esophageal varices and splenomegaly without any signs of liver cirrhosis. A portal hemodynamics study revealed a normal portosystemic gradient compatible with presinusoidal portal hypertension. Finally, IPH was diagnosed after a liver biopsy. IPH secondary to thiopurines is due to a 6-thioguanine nucleotide (6-TGN)-dependent reaction and occurs predominantly between three months and three years after the start of treatment. The onset is usually insidious and thrombocytopenia is the first manifestation. The definitive diagnosis is obtained by liver biopsy.