Discontinuation of Pneumocystis carinii pneumonia prophylaxis after start of highly active antiretroviral therapy in HIV-1 infection

Background Highly active antiretroviral therapy (HAART) has improved rates of CD4-lymphocyte recovery and decreased the incidence of HIV-1-related mor bidity and mortality. We assessed whether prophylaxis against Pneumocystis carinii pneumonia (PCP) can be safely discontinued after HAART is started. Methods We investigated 7333 HIV-1-infected patients already enrolled in Eu roSIDA, a continuing prospective observational cohort study in 52 centres a cross Europe and Israel. We did a person-years analysis of the rate of disc ontinuation of PCP prophylaxis and of the incidence of PCP after the introd uction of HAART into clinical practice from July, 1996. Findings The rate of discontinuation of primary and secondary PCP prophylax is increased up ro 21 . 9 discontinuations per 100 person-years of follow-u p after March, 1998. 378 patients discontinued primary (319) or secondary ( 59) prophylaxis a median of 10 months after starting HAART. At discontinuat ion for primary and secondary prophylaxis, respectively, the median CD4-lym phocyte counts were 274 cells/mu L and 270 cells/mu L, the median plasma HI V-1 RNA load 500 copies/mL, and the median lowest recorded CD4-lymphocyte c ounts 123 cells/mu L and 60 cells/mu L. During 247 person-years of follow-u p, no patient developed PCP (incidence density 0 [95% CI 0-1 . 5]). Interpretation The risk of PCP after stopping primary prophylaxis, especial ly in patients on HAART with a rise in CD4-lymphocyte count to more than 20 0 cells/mu L, is sufficiently low to warrant discontinuation of primary PCP prophylaxis. Longer follow-up is needed to confirm a similarly low risk fo r stopping secondary PCP prophylaxis.