Background: HIV-infected patients with sustained immunologic improvement from antiretroviral therapy may be able to discontinue chemoprophylaxis against Pneumocystis carinii pneumonia (PCP).
Objective: To compare PCP incidence in HIV-infected patients who had sustained CD4+ lymphocyte counts greater than 200 cells/mm3 and who either discontinued 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 prophylaxis 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 minimum CD4+ cell counts and lower viral loads than patients who continued PCP prophylaxis. Pneumocystis carinii pneumonia did not develop in either group (upper 95% exact binomial confidence limit of incidence for those who discontinued PCP prophylaxis, 2.3/100 person-years).
Conclusions: Discontinuation of PCP chemoprophylaxis may be appropriate for some HIV-infected ambulatory patients.
*For members of the HIV Outpatient Study Investigators, see Appendix.