Related Experiment Videos
Improved detection of Pneumocystis carinii by an immunofluorescence technique using monoclonal antibodies
M Orholm1, W Holten-Andersen, J D Lundgren
1Department of Infectious Diseases, Hvidovre Hospital, University of Copenhagen, Denmark.
Abstract:
To assess whether a recently developed indirect immunofluorescent stain using monoclonal antibodies was more sensitive in detecting Pneumocystis carinii than the combination of Giemsa and methenamine silver nitrate stains which has routinely been used in the laboratory, 88 lavage fluid specimens and 34 induced sputum specimens were examined. All specimens were stained by five techniques: immunofluorescence using a combination of three monoclonal antibodies (from the National Institutes of Health, USA), immunofluorescence using a single monoclonal antibody (from Dakopatts), Giemsa, methenamine silver nitrate and toluidine blue O. Immunofluorescence using the monoclonal antibodies from the NIH was significantly more sensitive than any other single staining method and than the combination of Giemsa and methenamine silver nitrate staining. The study also showed that the cytospin centrifuge was very suitable for the preparation of slides with lavage fluid and processed induced sputum. Finally, the sensitivity of examination of induced sputum to detect Pneumocystis carinii was found to be 50% when compared with bronchoalveolar lavage fluid. However, this sensitivity may increase through practice.
Insights
A new indirect immunofluorescent stain using monoclonal antibodies is more sensitive for detecting Pneumocystis carinii than traditional stains. This method improves diagnostic accuracy for Pneumocystis pneumonia.
Area of Science:
- Medical Mycology
- Diagnostic Pathology
- Immunofluorescence Assays
Background:
- Pneumocystis carinii pneumonia (PCP) diagnosis relies on microscopic examination of respiratory specimens.
- Traditional staining methods like Giemsa and methenamine silver nitrate have limitations in sensitivity.
- Monoclonal antibody-based immunofluorescence offers a potential improvement in diagnostic sensitivity.
Purpose of the Study:
- To compare the diagnostic sensitivity of a novel indirect immunofluorescent stain with conventional methods for detecting Pneumocystis carinii.
- To evaluate the efficacy of monoclonal antibodies in identifying Pneumocystis carinii in respiratory samples.
Main Methods:
- Examination of 88 lavage fluid and 34 induced sputum specimens.
- Staining techniques included immunofluorescence (NIH and Dakopatts monoclonal antibodies), Giemsa, methenamine silver nitrate, and toluidine blue O.
- Cytospin centrifugation was utilized for specimen preparation.
Main Results:
- Immunofluorescence using NIH-derived monoclonal antibodies demonstrated significantly higher sensitivity compared to all other single stains and the combined Giemsa/methenamine silver nitrate method.
- Cytospin centrifugation proved effective for preparing slides from lavage fluid and induced sputum.
- Induced sputum examination detected Pneumocystis carinii in 50% of cases compared to bronchoalveolar lavage fluid, with potential for improvement.
Conclusions:
- Indirect immunofluorescence with specific monoclonal antibodies offers superior sensitivity for Pneumocystis carinii detection.
- Monoclonal antibody-based immunofluorescence is a valuable diagnostic tool for Pneumocystis pneumonia.
- Optimized specimen preparation and examination techniques, including induced sputum, can enhance diagnostic yield.