The use of an indirect fluorescent antibody test for detecting Pneumocystis carinii.
Pneumocystis carinii pneumonia is a major cause of morbidity and mortality in immunocompromised patients. An indirect fluorescent antibody (IFA) test has been developed using monoclonal antibodies specific for antigens on the surface of P carinii. We tested the sensitivity and specificity of this IFA test for detecting P carinii in respiratory specimens of immunocompromised patients with pulmonary symptoms undergoing bronchoscopy. Both the bronchial wash and bronchoalveolar lavage specimens of patients with and without P carinii pneumonia were studied. The bronchoalveolar lavage and bronchial wash specimens were examined using modified Wright-Giemsa and methenamine silver stains. In addition, aliquots of the specimen were fixed and stained with IFA and read with a fluorescent microscope. Fifty-nine patients were found to have P carinii organisms. The bronchial wash specimen has been shown to be less sensitive than the bronchoalveolar lavage specimen for detecting the presence of P carinii. In the bronchial wash specimen from these 59 patients, only 60% had positive modified Wright-Giemsa stains, and 70% had positive methenamine silver stains. The IFA stain was positive in 93% of the specimens tested (significantly higher than the other two stains). There was only one false-positive IFA test result among the 54 patients tested with negative results. We found the IFA stain to be superior to conventional stains when examining less-than-adequate specimens, such as those from bronchial washes.
Baughman
R P
RP
Department of Medicine, University of Cincinnati Medical Center, OH.
Strohofer
S S
SS
Clinton
B A
BA
Nickol
A D
AD
Frame
P T
PT
D000913:Antibodies, Protozoan / Q000032:analysis*; D001992:Bronchoalveolar Lavage Fluid / Q000032:analysis / Q000469:parasitology; D005189:False Positive Reactions; D005455:Fluorescent Antibody Technique; D006658:Histoplasma / Q000032:analysis; D006801:Humans; D008709:Methenamine; D011020:Pneumonia, Pneumocystis / Q000175:diagnosis* / Q000469:parasitology; D013194:Staining and Labeling
D000913:Antibodies, Protozoan; D008709:Methenamine