Immune Reconstitution Syndrome after Successful Treatment ofPneumocystis cariniiPneumonia in a Man with Human Immunodeficiency Virus Type 1 Infection

We describe a 34-year-old man with human immunodeficiency virus infection who received successful treatment of minimally symptomatic Pneumocystis carinii pneumonia and who subsequently developed diffuse pulmonary infiltrates and hypoxia 2 weeks after initiation of combination antiretroviral therapy. Initial pathologic evaluation of lung-tissue samples revealed no organisms, but a polymerase chain reaction assay was strongly positive for P. carinii DNA. We hypothesize that this patient's clinical presentation denotes immune reconstitution syndrome in response to residual P. carinii antigen in the lung.