Immune modulator therapy for microscopic colitis in a case series of 73 patients

Background: Microscopic colitis (MC) is a common cause of chronic diarrhoea. Various treatment options have been described, but there are limited data describing outcomes of corticosteroid-sparing treatments. Aim: To evaluate the outcomes of patients with active MC treated with immune modulators. Methods: All patients seen at Mayo Clinic, Rochester between January 1, 1997 and November 30, 2016 with a histological diagnosis of MC were identified. Patients treated with an immune modulator of interest were selected and clinical outcomes recorded. Results: Seventy-three MC patients (50 collagenous colitis and 23 lymphocytic colitis) with a median disease duration of 24 months (range, 7-60) were included. The indications for treatment were budesonide-refractoriness in 66%, budesonide dependence in 29%, and budesonide intolerance in 5%. Median age was 51.8 years (range, 43.4-63.1) and 61 (84%) were female. Thiopurines were used in 49 patients (67%) for a median of 4 months (range, 1.5-15). Complete and partial response occurred in 43% and 22% respectively. Adverse effects resulting in therapy cessation occurred in 17 patients (35%). Twelve patients (16%) were treated with methotrexate for a median of 14 months (3-18.8). Complete and partial response occurred in 58% and 17%, respectively. Anti-TNF therapy was used in 10 patients (14%) for a median of 4 months (range, 2.3-5.5). Complete response occurred in four patients and partial response in four patients. Conclusions: The majority of patients with active MC responded to thiopurines, methotrexate, or anti-TNF therapy. Larger controlled studies are required to confirm the efficacy and safety of these medications in MC.