Pneumocystis carinii(PCP) infection remains a common complication of AIDS. NebuPent is indicated for prophylaxis of Pneumocystis Carinii infections in HIV positive patients. There is precedent for using this drug or Bactrim for prophylaxis in other immuno-compromised states than AIDS. For example,the National Comprehensive Cancer Network (NCCN) guidelines on prevention and treatment of cancer-related infections consider CLL patients receiving purine analogs or alemtuzumab (Campath, Genzyme) to be at intermediate- or high-risk, respectively, for developing infections. The guidelines recommend that patients receiving purine analog and/or alemtuzumab-containing regimens should be given prophylactic medications against viral infections and Pneumocystis infections, at a minimum.
While retrospective studies indicate that long-term steroid use increases the risk of PCP infection it is not known how these patients should be prophylaxed. The threshold for potential infection that warrants prophylaxis with its costs in side effects and expense is unknown, and the critical amount of immunosuppression necessary to increase risk for PCP is also unknown. Prophylaxis has been suggested for patients immunosuppressed owing to an underlying disease or immunosuppressive therapy. In some cancer centers, patients who receive corticosteroid therapy for longer than 4 weeks at a dose equivalent to 20 mg of prednisone per day are routinely are given PCP prophylaxis, as well as those in high-risk groups such as bone marrow transplant recipients and children with ALL.
In 2009, Kovacs and Masur summarized the first 100 years since identification of Pneumocystis. They concluded that in HIV-negative patients there is no reliable laboratory marker for risk of this infection, but that in these patients PCP is more likely to be an acute illness causing severe respiratory distress of rapid onset when compared with HIV-positive patients. That makes routine prophylaxis more reasonable. Their recommended approach is to use PCP prophylaxis in patients receiving at least 20 mg of prednisone per day for at least 1 month. They also note that steroid therapy can accelerate symptomatic and physiologic improvement and improve survival in patients with moderate or severe PCP. Since steroids are in themselves immunosupressive, management of corticosteroids in PCP-infected patients is quite complex.
Kovacs JA, Masur H. Evolving health effects of Pneumocystis: one hundred years of progress in diagnosis and treatment. JAMA. 2009;301:2578-2585.
Green H, Paul M, Vidal L, Leibovici L.Prophylaxis of Pneumocystis pneumonia in immunocompromised non-HIV-infected patients: systematic review and meta-analysis of randomized controlled trials. Mayo Clin Proc. 2007 Sep;82(9):1052-
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