Active Tuberculosis Complicates the Diagnosis and Treatment of Fibrostenosing Crohnʼs Disease

Abstract

62-year-old male with Crohn's disease (CD), presented for abdominal pain and weight loss. Patient was initially diagnosed with CD based of CTE 2 years prior. He was started on 5-ASA and lost to follow up. Upon re-presentation patient reported lower abdominal pain, hematochezia and weight loss. Lab evaluation negative. Colonoscopy showed a hepatic flexure stricture which could not be traversed. Biopsy showed mild to moderate chronic colitis with focal severe ulceration. CTE showed a 7 cm thickening and a focal hyper-enhancement of the ascending colon. We elected to resect due to his obstructive symptoms, weight loss and cancer risk. Surgery was to be followed by biologic therapy. In preparation for therapy QuantiFERON gold was positive. An ill-defined right upper lobe mass was seen on CXR. AFB in sputum confirmed active pulmonary tuberculosis. Active TB raised the possibility of an alternative diagnosis for the colonic stricture. The patient was started on 4 drug therapy. Following 10 weeks of therapy patient was deemed non-infectious and underwent a successful laparoscopic right hemicolectomy. Path showed focal mild to moderate chronic colitis with focal ulceration. Negative AFB stains. Post-op biologic therapy was anticipated. However, his active TB postponed initiation until completion of antibiotic therapy. As such the final plan was to perform colonoscopy 6 months post-op to assess for recurrent inflammation and if so would consider starting biologic therapy. The diagnostic dilemma of gastrointestinal TB and Crohn's disease is a common occurrence in TB endemic areas. It often presents similar to Crohn's disease with abdominal pain, weight loss, hematochezia, has similar imaging and endoscopic findings. It is important to differentiate between the two as they have opposing treatments. The risk of biologic therapy and re-activation of latent tuberculosis is well documented and screening for and surveying for TB is standard of care. But consideration of how to manage a patient with complicated Crohn's disease recently treated for active TB presents a dilemma. Biologic therapy is warranted to prevent recurrence of anastomotic stricture. A risk vs benefit discussion must be had and a suitable therapy individualized for the specific patient must be chosen. Vedolizumab, a gut specific, monoclonal antibody against a4b7 Integrin is considered to have a favorable safety profile with low incidence rates of serious infections.2057_A Figure 1. Histology2057_B Figure 2. Colon Resection Specimen