Detection of H. capsulatum antigen by Enzyme-linked Immunoassay (EIA) is well documented, and an improved 2nd generation assay exhibits increased sensitivity and specificity for urine and serum specimens as compared to the original EIA. The purpose of this study is to compare sensitivity for detection of antigen in bronchial alveolar lavage (BAL) specimens in the 2nd generation vs. original H. capsulatum antigen assay.
BAL specimens previously submitted for H. capsulatum antigen detection were evaluated concurrently in the new 2nd generation vs. original immunoassays.
Of the 39 BALs tested, 14 were positive in the 2nd generation assay vs. 10 in the original assay. For the positive specimens, the median antigen level was 4.15 EIA units in the 2nd generation vs. 1.36 EIA units in the original assay.
Testing of BAL samples for H. capsulatum antigen may aid in rapid diagnosis. Sensitivity of antigen detection in BALs was greater in the 2nd generation assay.
Bronchoscopy with BAL for Histoplasma antigen determination offers an adjunctive method for rapid diagnosis of pulmonary histoplasmosis. Improvements in the antigen immunoassay increase its sensitivity for diagnosis.
Chadi Hage, None.