[Legionella pneumonia after infliximab in a patient with rheumatoid arthritis].

The antagonists of tumour necrosis factor (anti-TNF) have been successfully used in several chronic inflammatory diseases such as Rheumatoid Arthritis (RA), but some studies have observed the development of infections by intracellular pathogens in patients using anti-TNF. We report a case of a female patient with previous diagnosis of RA for 16 years that used several disease-modifying anti-rheumatic drugs (DMARDs) that resulted in treatment failure, and then was treated with infliximab. After fifteen days of the second dose, the patient developed ventilatory-dependent chest pain, dry cough and dyspnea. She was hospitalized, and the diagnosis of pneumonia by Legionella pneumophila was confirmed by the presence of Legionella antigen in an urine test. TNF is an inflammatory cytokine that also acts inhibiting the bacterial growth of intracellular pathogens, and its inhibition seems to increase susceptibility to these infections in some patients.