Tuberculosis and granuloma formation in patients receiving anti-TNF therapy.

In patients receiving anti-tumor necrosis factor (TNF) therapy, a probable exacerbation of latent tuberculosis (TB) is a major adverse event. The impairment of granuloma differentiation is considered a characteristic feature of TB in these patients. In this report we present three patients with rheumatic disease who developed TB under infliximab treatment. All of them had typical granulomas on the biopsy specimens, indicating that the expected impairment of granuloma formation is not always the case. The notion of granuloma-free TB in patients receiving anti-TNF therapy could shift a clinician's path away from performing a biopsy, thus delaying the establishment of a correct diagnosis.