Hoq L. Reactivation of latent granulomatous infections by infliximab. Clin Infect Dis 2005; 41(Suppl 3):S194–8

Although infliximab and etanercept share tumor necrosis factor (TNF) as a common therapeutic target, accumulating data indicate that infliximab (an anti-TNF monoclonal antibody) poses a greater risk of reac-tivation of latent granulomatous infections than does etanercept (a soluble TNF receptor). Similarly, infliximab is effective for the treatment of chronic granulomatous inflammatory conditions (e.g., Crohn disease) for which etanercept is ineffective. The ability of infliximab to disrupt established granulomas may be distinct from its ability to neutralize soluble TNF. Further research to elucidate the mechanism of the antigranuloma activity of infliximab is warranted. TNF AND GRANULOMA BIOLOGY Granulomas provide a strategy for containing intracel-lular infections that cannot otherwise be eradicated by host defenses. The ingestion by a lung macrophage of an indigestible pathogen, such as Mycobacterium tuber-culosis, sets in motion a process in which neutrophils, macrophages, and, subsequently, cells with increasing specificity for M. tuberculosis (i.e., natural killer cells, g