Intermittent granulocyte and monocyte apheresis versus mercaptopurine for maintaining remission of ulcerative colitis: a pilot study.

The effect of granulocyte and monocyte adsorption apheresis (GMA) on prevention of relapse of ulcerative colitis (UC) is not clear. This was a pilot open-labeled, prospective, randomized, unblinded study to compare the tolerability and efficacy of intermittent GMA (once every 2 weeks) with mercaptopurine to maintain remission of UC. Twenty-one patients with UC, who had achieved remission by induction therapies were randomly assigned to receive either intermittent GMA (N = 10) or oral mercaptopurine (0.5 mg/kg per day; N = 11). The study period was 24 months. The rate of the patients maintaining remission and the incidences of adverse effects were compared between the two groups. At 24 months, seven of 10 patients (70.0%) on intermittent GMA and seven of 11 patients (63.6%, P = 1.00) on oral mercaptopurine were still in remission. Three patients relapsed in each group. One patient taking mercaptopurine, but none receiving intermittent GMA, dropped out because of adverse effects. Intermittent therapy with GMA was well tolerated and a substantial proportion of patients maintained remission. Intermittent GMA therapy in maintaining remission of UC merits further investigation.