Discontinuation of prophylaxis for Pneumocystis carinii pneumonia in HIV-1-infected patients treated with highly active antiretroviral therapy

Background Prophylactic drugs for Pneumocystis carinii pneumonia (PCP) are strongly recommended for HIV-1-infected patients with CD4 cell counts of less than 200 cells/mu L. Because of the highly active antiretroviral therapy (HAART) currently available, we speculated that prophylaxis can be discontinued in patients with CD4 cell counts of more than 200 cells/mu L.

Methods In this prospective observational study, PCP prophylaxis (primary or secondary) was discontinued in HIV-1-infected patients whose CD4 cell count had increased above 200 cells/mu L (documented twice with an interval of at least 1 month) as a result of HAART. Patients and their CD4 cell counts were monitored every 3 months. The primary endpoint of the study was the occurrence or reoccurrence of PCP.

Findings 78 patients were enrolled: 62 patients were receiving prophylaxis for primary prevention of PCP and 16 patients for secondary prevention of PCP. At the time of discontinuation of prophylaxis, the mean CD4 cell count was 347 cells/mu L, and HIV-1-RNA was not detectable in 61 patients. The lowest mean CD4 cell count during prophylaxis was 79 cells/mu L. Patients stopped prophylaxis 9.8 (SD 6.4) months after they started HAART, The mean follow-up after discontinuation of prophylaxis was 12.7 (SD 7.6) months, and none of the patients developed PCP (97.5% one-sided CI 0-4.4%).

Interpretation The preliminary results of this study indicate that PCP prophylaxis can be stopped safely in HIV-1-infected patients whose CD4 cell counts have increased above 200 cells/mu L after treatment with HAART.