Mycobacterial infections in the era of modern biologic agents.

Patients with rheumatologic disease are at increased risk for mycobacterial infections because of both immunocompromising therapy and preexisting lung damage from the disease itself. Tuberculosis is uncommon in the United States; however, it is relatively more prevalent in immigrants, minorities, elderly, persons with acquired immune deficiency syndrome and among healthcare workers. In the United States, the nontuberculous mycobacteria (NTM) are now more prevalent than tuberculosis. Although initially noted in men with chronic obstructive pulmonary disease, recent observations indicate increasing numbers of NTM cases in slender white women. Because of the often atypical presentation of NTM lung disease, diagnosis is commonly delayed. Because there is solid evidence that tumor necrosis factor-alpha-modifying agents are associated with serious NTM disease, it is important that specific screening tests (eg, chest x-ray, computed tomographic lung scans, sputum cultures or referral to pulmonary or infectious disease specialists) be used before initiating anti-tumor necrosis factor therapy.