Alveolar damage in AIDS-related Pneumocystis carinii pneumonia.
OBJECTIVE
Pneumocystis carinii pneumonia is the most common and serious of the pulmonary complications of AIDS. Despite this, many basic aspects in the pathogenesis of HIV-associated P carinii pneumonia are unknown. We therefore undertook a light and electron microscopic study of transbronchial biopsy specimens to compare pathologic features of P carinii pneumonia and other HIV-related lung diseases.


METHODS
Thirty-seven consecutive HIV-infected patients undergoing a diagnostic bronchoscopy.


RESULTS
P carinii pneumonia was characterized by an increase in inflammation, edema, exudate, fibrosts, type II pneumocyte proliferation, and cellular infiltration of the alveolar wall when compared with other lung diseases (all p < 0.05). Electron microscopy showed apposition of the trophozoite to the type I pneumocyte. Erosion of type I pneumocytes was observed in 13 of 15 patients with P carinii pneumonia, whereas none without P carinii pneumonia had this finding (p < 0.05). Erosion of the type II pneumocyte was not observed.


CONCLUSIONS
Inflammation, interstitial fibrosis, and alveolar epithelial erosion are characteristic features of P carinii pneumonia. The changes may form the pathologic basis for the respiratory failure seen in patients with P carinii pneumonia. Electron microscopy did not show any diagnostie advantage over conventional light microscopy using routine stains.
Benfield
T L
TL
Departments of Infectious Diseases and Pathology, EM Division, University of Copenhagen, Hvidovre Hospital, Denmark.
Prentø
P
P
Junge
J
J
Vestbo
J
J
Lundgren
J D
JD
D017088:AIDS-Related Opportunistic Infections / Q000473:pathology*; D000328:Adult; D000368:Aged; D001706:Biopsy; D001992:Bronchoalveolar Lavage Fluid / Q000382:microbiology; D001999:Bronchoscopy; D002455:Cell Division; D015169:Colony Count, Microbial; D004396:Coloring Agents; D003593:Cytoplasm / Q000648:ultrastructure; D004487:Edema / Q000473:pathology; D004848:Epithelium / Q000473:pathology / Q000648:ultrastructure; D005122:Exudates and Transudates; D005260:Female; D006801:Humans; D007249:Inflammation / Q000473:pathology; D008171:Lung Diseases / Q000473:pathology; D008297:Male; D008854:Microscopy, Electron; D008875:Middle Aged; D015388:Organelles / Q000648:ultrastructure; D011010:Pneumocystis / Q000166:cytology; D016720:Pneumocystis Infections / Q000473:pathology*; D011650:Pulmonary Alveoli / Q000473:pathology* / Q000648:ultrastructure; D011658:Pulmonary Fibrosis / Q000473:pathology; D012131:Respiratory Insufficiency / Q000209:etiology / Q000473:pathology
D004396:Coloring Agents