Diagnosis of acute pulmonary histoplasmosis by antigen detection.

Background. Antigen detection, which has proven useful in diagnosis of disseminated histoplasmosis, has not been studied in acute pulmonary histoplasmosis (APH). Because treatment is indicated in most patients with moderately severe or severe APH, antigen detection for rapid diagnosis could be helpful. Methods. Histoplasma antigen detection was evaluated in 130 patients with APH. Results. Antigenuria was detected in 64.6%, antigenemia in 68.6%, and antibody in 64.3%. If both urine and serum specimens were tested, antigen was detected in 82.8%, of which 45.8% had antigenemia only; and if both antigen and antibody were measured, results were positive in 93.3%, of which antigen only was positive in 35.7%. Conclusions. Testing for antigenemia, antigenuria, and antibodies using the complement fixation test offers a sensitive, noninvasive method for diagnosis of APH.