TNF and infection: TNF inhibition can lead to infection or reactivation of granulomatous infections like tuberculosis and fungal infections, such as Histoplama, Coccidioides, Aspergillus, Pnemocystis and Nocardia. The impaired macrophage-killing capacity can also facilitate bacterial infections, like Pneumococcus or Legionella pulmonary infections as well as disseminated infections by Salmonella or Listeria. Although less frequent, patients treated with anti-TNF agents can develop invasive viral infections sustained by varicella-zoster virus or cytomegalovirus, as occur in immunosuppressed patients [4].