Organizing pneumonia as a manifestation of Pneumocystis jiroveci immune reconstitution syndrome in HIV-positive patients: report of 2 cases.

Organizing pneumonia (OP) is a nonspecific response to various forms of lung injury. Although patients with human immunodeficiency virus (HIV) infection tend to develop several respiratory disorders, especially infections and malignances, the association of HIV infection and OP is unusual. Pneumocystis jiroveci infection is also rarely associated with OP. We describe the radiologic findings in 2 HIV-positive patients who shortly after introduction of highly active antiretroviral therapy, presented with clinical and radiologic deterioration, despite elevation of the CD4 cell count and viral load decrease. In both patients, clinical and radiologic features were consistent with OP and lung biopsy revealed OP associated with P. jiroveci infection. These findings are consistent with immune reconstitution syndrome due to P. jiroveci.