Outcomes and risk factors for mortality in Pneumocystis pneumonia patients with rheumatoid arthritis: A multicentre retrospective cohort study

ABSTRACT Objectives The aim is to evaluate outcomes and risk factors for death in patients with rheumatoid arthritis (RA) who developed Pneumocystis pneumonia (PCP). Methods We included RA patients who were diagnosed with PCP at seven participating community hospitals between July 2005 and October 2020. Clinical features were compared between survivors and non-survivors. Disease-modifying antirheumatic drugs (DMARDs) before PCP onset and after PCP recovery were also examined. Results Seventy RA patients developed PCP, and among them, 60 (85.7%) received methotrexate (MTX) monotherapy (40%) or MTX combination therapy with other DMARDs (45.7%). PCP was more likely to occur after 12 months of MTX monotherapy and within 3 months of MTX combination therapy. Thirteen patients (18.6%) died despite PCP treatment. Multivariable logistic regression analysis revealed that coexisting RA-associated interstitial lung disease (odds ratio, 6.18; 95% confidence interval, 1.17–32.63) and delayed PCP treatment with anti-Pneumocystis drugs (odds ratio, 15.29; 95% confidence interval, 1.50–156.15) are significant risk factors for PCP mortality in RA patients. Most survivors successfully resumed DMARD therapy without PCP prophylaxis; one recurrent PCP case was observed during follow-up (median, 4.1 years). Conclusions To avoid a treatment delay, RA patients should be followed up for signs and symptoms of PCP development, especially those with RA-associated interstitial lung disease.