Detection of circulating Aspergillus fumigatus antigen in bone marrow transplant patients.

A competitive inhibition enzyme-linked immunosorbent assay able to detect Aspergillus fumigatus antigenemia at a concentration sensitivity of 68 ng/ml was developed. To test the utility of this assay in the diagnosis of invasive aspergillosis, serum was collected twice weekly from all patients in a bone marrow transplant unit. When analyzed retrospectively, A. fumigatus antigen was detected in three of four patients (75%) with proved invasive aspergillosis at autopsy or biopsy and in a solitary patient with suspected but not proved invasive aspergillosis. No antigen was detected in 17 bone marrow transplant unit patients without proved or suspected invasive aspergillosis or in 16 healthy control subjects. Detection of antigen rose with an increasing number of samples tested. A. fumigatus antibody levels were not helpful in the diagnosis of invasive aspergillosis, although in a few patients antibody levels decreased just before death.