Bronchoalveolar lavage fluid cytology in patients with Pneumocystis carinii pneumonia

Objective: To evaluate bronchoalveolar lavage (BAL) cytology and organmism burden in patients with Pneumocystis carinii pneumonia (PCP) who were infected with the human immunodeficiency virus (HIV) and in those with other immunodefiencies. STUDY DESIGN: BAL fluid samples from patients with PCP were selected (HIV-infected patients, n = 15; patients with other immunodefiencies, n = 11). May-Grunwald-Giemsa-strained cytoceentrifuge preparations were evaluated. Foamy alveolar casts (FACs) and P carinii clusters were counted. RESULTS: The numbers of FACs and P carinii clusters in BALs fluid samples of HIV-infected patients were significantly higher as compared to those in samples from patients with other immunodeficiencies. Stricking cytologic findings observed in half the samples from both patients groups included the presence of foamy alveolar macrophages, activated lymphocytes, plasma cells and reactive type II pneumocytes. Furthermore, a peculiar cell type, "nonidentified cell" (NIC), was observed almost exclusively in BAL fluid samples from HIV-infected patients. CONCLUSION: BAL fluid samples from HIV-infected patients with PCP displayed higher organism burdens as compared to those from patients with other immunodefiencies. Moreover, cytologic findings suggestive of noninfectious lung conditions were common in BAL fluid samples obtained from patients with PCP. Further studyis required to elucidate the identity of the NIC cell type.