Biologics for the Management of Inflammatory Bowel Disease: A Review in Tuberculosis-Endemic Countries

The advent of biologics and biologic therapy has transformed the management of inflammatory bowel disease (IBD) with enhanced early and adequate responses to treatment, fewer hospitalizations, a reduced need for surgery, and unprecedented outcomes including complete mucosal and histologic healing. However, an important issue with the use of anti-tumor necrosis factor (anti-TNF) agents in IBD is the increased risk of tuberculosis (TB). This is compounded by the diagnostic dilemma when differentiating between Crohn's disease and gastrointestinal TB, and the potentially serious consequences of initiating an incorrect treatment in the case of misdiagnosis. The interplay between IBD and TB is most relevant in Asia, where more than 60% of the 10.4 million new TB cases in 2016 were reported. A number of studies have reported an increased risk of TB with anti-TNF agents, including in patients who had tested negative for TB prior to treatment initiation. The limited evidence currently available regarding adhesion molecule antagonists such as vedolizumab suggests a comparatively lower risk of TB, thus making them a promising option for IBD management in TBendemic regions. This comprehensive review examines the available literature on the risk of TB with the use of biologics in the TB-endemic regions of Asia, focusing on the diagnostic dilemma, the risk of reactivation, and the optimized management algorithms for latent and active disease.