[Pneumonia, pneumocystis pneumonia].

Pneumonia (almost equally bacterial) is the most common and serious adverse events of the patients with rheumatoid arthritis (RA) prescribing anti-tumor necrosis factor(TNF) agents. Furthermore, it has been shown that Pneumocystis jirovecii should be one of the important causal microorganisms by the results of postparketing all-patients registration surveillance in Japan. Older age, pulmonary comorbidities, diabetes mellitus, or dosage of co -prescribing glucocorticoid has been extracted as a predictable risk factor respectively and synergistically by the surveillance. When prescribing anti-TNF agents, it is possible that considering these risk factors might reduce the incidence of bacterial or Pneumocystis pneumonia in RA patients.