Pneumocystis carinii pneumonia prophylaxis in patients with rheumatic diseases undergoing immunosuppressive therapy - Prevalence and associated features

Pneumocystis carinii (PCP) has been recognized as a cause of pneumonia in i mmuocompromised patients, most notably in AIDS patients, but also in those receiving immunosuppressive therapy for a variety of other conditions, incl uding malignancy, having an organ transplant, connective tissue diseases, a nd vasculitic syndromes. Ln non-HIV PCP patients, presentations may be more dramatic than in HIV-related PCP and the mortality may be higher, thus emp hasizing 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 rates noted in Wegener's granulomatosis and the lowest no ted in rheumatoid arthritis. Prophylactic regimens should be used in patients with Wegener's granulomato sis taking cyclophosphamide and daily corticosteroids and in other rheumati c disease patients who are treated with this regimen, such as in PAN, micro scopic polyarteritis, or severe systemic lupus erythematosus. Prophylaxis s hould be strongly considered in patients taking prolonged, high doses of da ily corticosteroids (>40mg/day for >3 months) with a second immunosuppressi ve agent other than cyclophosphamide, such as methotrexate, for example, as in PM/DM and in alternative regimens for Wegener's granulomatosis. Emergin g data suggest the utility of CD4 counts as a method to distinguish those a t highest risk for PCP to selectively apply prophylactic therapy. TMP-SMX i s the usual first choice for prophylaxis.