Pneumocystis carinii pneumonia prophylaxis in patients with rheumatic diseases undergoing immunosuppressive therapy: prealence and associated features.

Pneumocystis carini (PCP) has been recognized as a cause of pneumonia in immuocompromised patients, most notably in AIDS patients, but also in those receiving immunosuppressive therapy for a variety of other conditions, including malignancy, having an organ transplant, connective tissue diseases, and vasculitic syndromes. In non-HIV PCP patients, presentations may be more dramatic than in HIV-related PCP and the mortality may be higher, thus emphasizing the need to identify and provide prophylaxis for those at highest risk for PCP. The incidence of PCP varies in different rheumatic disorders, with the highest rated noted in Wegener's granulomatosis and the lowest noted in rheumatoid arthritis. Prophylactic regimens should be used in patients with Wegener's granulomatosis taking cyclophosphamide and daily corticosteroids and in other rheumatic disease patients who are treated with this regimen, such as in PAN, microscopic polyarteritis, or severe systemic lupus erythematosus. Prophylaxis should be strongly considered in patients taking prolonged, high doses of daily corticosteroids (>40mg/day for > 3 months) with a second immunosuppressive agent other than cyclophosphamide, such as methotrexate, for example, as in PM/DM and in alternative regimens for Wegener's granulomatosis. Emerging data suggest the utility of CD4 counts as a method to distinguish those at highest risk for PCP to selectively apply prophylactic therapy. TMP-SMX is the usual first choice for prohpylaxis.