Discontinuation of secondary prophylaxis against Pneumocystis carinii pneumonia in patients with HIV infection who have a response to antiretroviral therapy. Eight European Study Groups.

BACKGROUND Patients with human immunodeficiency virus (HIV) infection and a history of Pneumocystis carinii pneumonia are at high risk for relapse if they are not given secondary prophylaxis. Whether secondary prophylaxis against P. carinii pneumonia can be safely discontinued in patients who have a response to highly active antiretroviral therapy is not known. METHODS We analyzed episodes of recurrent P. carinii pneumonia in 325 HIV-infected patients (275 men and 50 women) in eight prospective European cohorts. Between October 1996 and January 2000, these patients discontinued secondary prophylaxis during treatment with at least three anti-HIV drugs after they had at least one peripheral-blood CD4 cell count of more than 200 cells per cubic millimeter. RESULTS Secondary prophylaxis was discontinued at a median CD4 cell count of 350 per cubic millimeter; the median nadir CD4 cell count had been 50 per cubic millimeter. The median duration of the increase in the CD4 cell count to more than 200 per cubic millimeter after discontinuation of secondary prophylaxis was 11 months. The median follow-up period after discontinuation of secondary prophylaxis was 13 months, yielding a total of 374 person-years of follow-up; for 355 of these person-years, CD4 cell counts remained at or above 200 per cubic millimeter. No cases of recurrent P. carinii pneumonia were diagnosed during this period; the incidence was thus 0 per 100 patient-years (99 percent confidence interval, 0 to 1.2 per 100 patient-years, on the basis of the entire follow-up period, and 0 to 1.3 per 100 patient-years, on the basis of the follow-up period during which CD4 cell counts remained at or above 200 per cubic millimeter). CONCLUSIONS It is safe to discontinue secondary prophylaxis against P. carinii pneumonia in patients with HIV infection who have an immunologic response to highly active antiretroviral therapy.