Background Pneumocystis pneumonia (PCP) is rare, but life-threatening complications in patients with rheumatoid arthritis (RA). PCP in RA exhibits differently from PCP in acquired immunodeficiency syndrome (AIDS).
Objectives The aim of this study is to reveal clinical and laboratory differences between PCP in patients with RA and PCP in AIDS.
Methods We reviewed electric chart of our hospital from 1/2006 to 12/2011. PCP was difined by the following criteria a) symptoms and radiological findings compatible with PCP b) detection of P. jirovecii by polymerase chain reaction (PCR) in respiratory specimens, c) elevated plasma (1$→ $3)-β-D-glucan level. We compared the clinical features between RA patients and AIDS patients.
Results Forty-one patients were diagnosed with PCP: 15 with RA, 10 with AIDS, 8 with connective tissue disease (CTD), 3 with cancer, 5 with others. In RA patients, 6 patients were on biologic therapy with or without low dose prednisolone. Seven patients were treated with low dose prednisolone and non-biologic DMARDs: 5 on methotrexate, 2 on methotrexate and tacrolimus, and 2 on steroids alone. Positivity of Grocott stain in RA patients was significantly lower than that in AIDS patients (7.1% vs 77.8%, p=0.0005). Serum LDH and CRP in RA patients were significantly higher than those in AIDS patients (p=0.04 and p=0.004, respectively). Three in RA patients died while none in AIDS patients.
Conclusions In RA patients, low dose steroids or DMARDs can induce PCP and PCR method should be used to detect P. jirovecii. We speculate PCP in RA patients may have more intense inflammation with less parasite burden and, as a result, worse prognosis than PCP in AIDS patients
Disclosure of Interest None Declared