THE USE OF AN INDIRECT FLUORESCENT-ANTIBODY TEST FOR DETECTING - PNEUMOCYSTIS-CARINII

  • 1 September 1989
    • journal article
    • research article
    • Vol. 113  (9) , 1062-1065
Abstract
P. 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 an bronchoalveolar lavage specimens of patients with and without P. carinii pneumonia were studied. The bronochalveolar 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 brochial 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 speciments, such as those from bronchial washes.