Anti-TNF treatment and miliary tuberculosis in Crohn's disease

Tumour necrosis factor alpha (TNFalpha) has a central role in the host immune response to mycobacterial infection.TNFalpha blockade may therefore result in reactivation of recent or remotely acquired infection. In reported mycobacterium tuberculosis infections, extra-pulmonary and disseminated tuberculosis (TB) was common, appeared rapidly, and if unrecognized, with fatal outcome. We present a female patient with miliary TB following treatment with infliximab for fistulizing Crohn's disease.

Five years before admission, the patient was diagnosed with Crohn's disease, with inflammation limited to the terminal ileum and sigmoid colon and has been on azathioprine 100 mg/day for the last 10 months. Three months before admission to the hospital she developed an enterocutaneous fistula for which therapy with infliximab was started in addition to azathioprine therapy. A tuberculin skin test and a chest x-ray were performed prior to the first infusion with normal findings. She presented with a 6-week history of fever, weakness, weight-loss and a 2-week dry cough. Chest x-ray and computed tomography displayed remarkable bilateral hilar and mediastinal lymphadenopathy and uniformly distributed fine nodules throughout both lung fields varying in size from 2 to 3 mm, without any signs of cavitation. Since there were clinical and morphological signs that indicated miliary TB, the treatment with antituberculous therapy was started and six weeks later all of the symptoms completely resolved and the lesions visible on x-ray diminished.

The clinical use of TNF-inhibitors is associated with increased risk of developing tuberculosis. Physicians should be aware of the increased risk of reactivation of TB among patients treated with anti-TNF agents and regularly look for usual and unusual symptoms of TB.