Outcomes of treatment for latent tuberculosis infection in patients with inflammatory bowel disease receiving biologic therapy

Background: Treatment for latent tuberculosis infection (LTBI) is of particular concern in patients with inflammatory bowel disease (IBD) initiating biologic therapies to prevent tuberculosis (TB) reactivation. This study aimed to evaluate the effectiveness of LTBI treatment in IBD patients receiving biologic therapy. Methods: There was a retrospective review of all IBD patients diagnosed with LTBI following a tuberculin skin test (TST) and/or interferon gamma release assay (IGRA) and who received biologic therapy between 2002 and 2016. The primary outcome was tuberculosis reactivation after completion of LTBI treatment. Results: Three-hundred twenty-nine IBD patients were identified, and 35 (27 Crohn's disease; 8 ulcerative colitis) met the study inclusion criteria. The mean age was 38.3 years, and 68.6% were male. The most common LTBI treatment regimen was isoniazid (INH) for 9 months (74%). Biologic therapies used were infliximab (40%), adalimumab (29%), vedolizumab (20%), and certolizumab pegol (11%). Combination therapy with an immunomodulator was administered in 57% of cases. The median time from initiation of LTBI treatment to biologics was 43 days. The mean duration of follow-up was 2.9 years. The estimated median annual risk of TB reactivation without treatment was 0.52% by a prediction formula. Only 1 patient taking adalimumab monotherapy developed reactivation of TB several years after completing 6 months of isoniazid therapy. The estimated TB reactivation rate was 0.98 cases per 100 patient-years of follow-up in our cohort. Conclusions: Treatment for LTBI in patients with IBD treated with biologics is effective but does not eliminate the risk of reactivation.