A research team from the Johns Hopkins Division of Rheumatology lead by Christopher Mecoli, M.D., M.H.S, studied medical records of patients with rheumatic diseases who were admitted to the Johns Hopkins Hospital for pneumocystis jiroveci pneumonia (PJP) infection over a 20-year period (1996-2015). PJP is an uncommon but severe lung infection that can occur in patients with rheumatic disease, in particular in those who are taking medications that suppress the immune system.
Why was this study done?
Although PJP infection is rare, it can be deadly. This is especially important in people with compromised immune systems, including those with rheumatic diseases on immunosuppressive therapies. It is known from the literature that people taking more than 20mg of prednisone daily for over 4 weeks are at increased risk for this severe infection and are recommended to take preventative therapy (prophylaxis). However, there is little data available from a single hospital to understand the prevalence of PJP and impact of medications in patients with rheumatic diseases. In this study, the authors sought to identify which rheumatic diseases, medications and doses were most associated with developing PJP. In addition, this study determined the trend in PJP seen among patients with rheumatic disease over a 20-year period at the Johns Hopkins Hospital.
How was this study done?
The authors conducted a historical review of all admitted patients to the Johns Hopkins Hospital who received a diagnosis of PJP and had an underlying diagnosis of a rheumatic disease from 1996-2016. They described the clinical characteristics of these patients including their medications, doses, and white cell count as well as their mortality rate.
What were the major findings?
Twenty-one cases of confirmed PJP in patients with rheumatic diseases were identified over the 20-year period, averaging one case per year. The most common underlying rheumatologic conditions found in these patients were inflammatory myopathy, lupus, and granulomatosis with polyangiitis. None of these 21 patients were receiving prophylaxis for PJP upon admission. Eighteen (86%) were receiving more than 20 mg prednisone daily at the time of PJP diagnosis, which was previously shown to increase the risk of PJP infection in other patient groups. However, 3 additional people with PJP were treated with less than 20 mg prednisone, but all received treatment with additional immunosuppressive medications including cyclophosphamide. Overall, there was a 43% (9/21) mortality rate among these patients following PJP infection. The use of additional immunosuppressive medications, presence of documented lung disease, or low white blood cell count did not predict the outcome of these patients.
What is the impact of this work?
PJP infection is associated with a high mortality rate yet is a largely preventable complication of rheumatic disease treatment. Physicians should consider initiating prophylaxis to protect against PJP infection for patients exceeding the daily 20 mg prednisone threshold, and those receiving cyclophosphamide. The impact of the duration of therapy was not studied in this review and is an important variable to consider in future studies since patients with rheumatic diseases can receive long-term treatment with immunosuppressive drugs.
Link to original research article:
Pneumocystis jiroveci pneumonia in rheumatic disease: a 20-year single-centre experience. Mecoli CA, Saylor D, Gelber AC, Christopher-Stine L. Clin Exp Rheumatol. 2017 Jan 27