Acute Lower Respiratory Tract Infections in Patients with Rheumatoid Arthritis

Objective: To determine whether drugs used in the treatment of rheumatoid arthritis (RA) contribute to the increased risk of respiratory infection or influence its outcome.

Methods: We identified all episodes of lower respiratory tract infection (LRTI) in our RA population over a 12 month period. A detailed drug history was recorded in each case, together with the clinical outcome. Premorbid illnesses and admission data were collected and analyzed to assess the influence of oral steroids and disease modifying antirheumatic drugs (DMARD) on outcome.

Results: The overall annual incidence of LRTI in patients with RA was 2.3% with a mortality rate of 22.5%. Demographic factors predicting LRTI included older age and male sex. Oral steroids and not taking DMARD were also associated with an increased risk of hospital admission with LRTI. Being male and having RA for over 10 years trended to the prediction of death as a result of infection. Taking DMARD was not associated with any adverse outcome.

Conclusion: Respiratory infection is common in patients with RA and carries a high mortality. Oral steroids predispose to infection, while DMARD do not. Increasing age and male sex also predispose to respiratory tract infection.