Discontinuation of chemoprophylaxis against Pneumocystis carinii pneumoniain patients with HIV infection

Background: HIV-infected patients with sustained immunologic improvement fr om antiretroviral therapy may be able to discontinue chemoprophylaxis again st Pneumocystis carinii pneumonia (PCP). Objective: To compare PCP incidence in HIV-infected patients who had sustai ned CD4(+) lymphocyte counts greater than 200 cells/mm(3) and who either di scontinued or continued PCP prophylaxis. Design: Nonrandomized prospective cohort study. Setting::10 HIV clinics in eight U.S, cities. Patients: 146 patients had follow-up visits for a mean of 18.2 months after discontinuation of PCP prophylaxis, and 345 patients who continued PCP pro phylaxis had follow-up visits for a mean of 14.0 months. Measurements: Incidence of PCP. Results: Patients who discontinued PCP prophylaxis had higher maximum and m inimum CD4(+) cell counts and lower vira I loads than patients who continue d PCP prophylaxis. Pneumocystis carinii pneumonia did not develop in either group (upper 95% exact binomial confidence limit of incidence for those wh o discontinued PCP prophylaxis, 2.3/100 person-yea rs). Conclusions: Discontinuation of PCP chemoprophylaxis may be appropriate for some HIV-infected ambulatory patients.