Diagnosis of histoplasmosis by antigen detection in BAL fluid.
BACKGROUND
Detection of antigen in BAL is useful for diagnosis of histoplasmosis. The MVista Histoplasma antigen enzyme immunoassay has been modified to permit quantification. The purpose of this study is to compare the sensitivity of the quantitative antigen detection assay with cytopathology and culture of BAL specimens.


METHODS
BAL from patients with histoplasmosis who were evaluated at the Indiana University Medical Center and controls without histoplasmosis were studied. BAL fluid was tested in the quantitative Histoplasma antigen assay.


RESULTS
Antigen was detected in the BAL in 93.5% of patients with histoplasmosis, 80% with blastomycosis, and 0% of controls with nonfungal infections. Antigen was detected in the urine of 79% and serum in 65% of patients with histoplasmosis. Cytopathology was positive in 48% and culture in 48% of patients with histoplasmosis, and 40% and 60% of patients with blastomycosis, respectively. Serology was positive in 65%. Combining BAL antigen detection and BAL cytopathology, both methods for rapid diagnosis, the sensitivity was 96.8% in histoplasmosis and 80% in blastomycosis.


CONCLUSIONS
Detection of antigen in BAL complements antigen detection in serum and urine as an objective diagnostic test for histoplasmosis.
Hage
Chadi A
CA
Department of Medicine, Roudebush VA Medical Center, Indiana University, Indianapolis, IN 46202, USA. chage@iupui.edu
Davis
Thomas E
TE
Fuller
Deanna
D
Egan
Lindsey
L
Witt
John R
JR
Wheat
L Joseph
LJ
Knox
Kenneth S
KS
D000946:Antigens, Fungal / Q000032:analysis; D001759:Blastomycosis / Q000175:diagnosis; D001992:Bronchoalveolar Lavage Fluid / Q000276:immunology*; D001999:Bronchoscopy; D003937:Diagnosis, Differential; D004797:Enzyme-Linked Immunosorbent Assay; D006658:Histoplasma / Q000276:immunology*; D006660:Histoplasmosis / Q000175:diagnosis*; D006801:Humans; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D000946:Antigens, Fungal