Performance Characteristics of the Platelia Aspergillus Enzyme Immunoassay for Detection of Aspergillus Galactomannan Antigen in Bronchoalveolar Lavage Fluid

Abstract

We have evaluated the Platelia Aspergillus enzyme immunoassay for detection of galactomannan in bronchoalveolar lavage (BAL) specimens in solid organ transplant patients with aspergillosis. The precision and reproducibility in serum or BAL to which galactomannan was added were similar. Sensitivity was 81.8% in patients with aspergillosis, and specificity was 95.8% in lung transplant patients who underwent BAL for surveillance for infection or rejection. Among transplant controls, positive results were more common in patients (i) who underwent diagnostic BAL performed for evaluation of symptoms or chest computed tomographic abnormalities, (ii) who had undergone lung transplantation, or (iii) who were colonized with Aspergillus. Galactomannan testing in BAL is useful for diagnosis of aspergillosis in transplant patients. The significance of positive results in patients without confirmed aspergillosis requires further evaluation.Invasive aspergillosis (IA) is common in hematopoietic stem cell and solid organ transplant patients, and the diagnosis often is determined based on bronchoalveolar lavage (BAL) (11). Galactomannan (GM) antigenemia detection is a useful method for the early diagnosis of IA (7,11,12). Several studies in hematologic patients show that detection of Aspergillus GM in BAL can be a sensitive method for the diagnosis of IA. The sensitivity was 89% or higher, and the specificity was 87 to 100% (1, 9, 10). In two studies that compared BAL and serum, sensitivity was lower in serum than in BAL: 47% versus 100% (1) and 44% versus 89%, respectively (9). False-positive results occurred in patients receiving piperacillin-tazobactam, in whom antigenemia also was present (9). False-positive results have also been reported when Plasmalyte was used to perform BAL (4). Positive BAL results may eliminate the need for additional invasive procedures in some patients (10).We reported previously the detection of Aspergillus GM in BAL from solid organ transplant patients with IA (2, 6). We have further analyzed here those studies and provide additional support for use of BAL testing for diagnosis of IA, including a more detailed analysis of specificity, precision, and reproducibility. MATERIALS AND METHODSClinical materials. The BAL specimens from patients with IA (n ϭ 11) and controls (n ϭ 185) have been previously described (2, 6). Four patients had proven and seven had probable IA, according to published criteria (3). BAL specimens from which Aspergillus or other mold was isolated were considered to be colonized if the patient failed to meet these criteria (i.e., if cultures were not associated with a mold resembling Aspergillus by cytology or histopathology of lung tissue, were not obtained from a sterile site, or were not associated with compatible abnormalities on chest computed tomography [CT] if isolated from a nonsterile site) (5).Transplant controls included 119 lung transplant patients who underwent bronchoscopy to monitor for infection or rejection (surveillance BAL) and 66 patients with a variety of tra...

Diagnosis of Invasive Aspergillosis by a Commercial Real-Time PCR Assay for Aspergillus DNA in Bronchoalveolar Lavage Fluid Samples from High-Risk Patients Compared to a Galactomannan Enzyme Immunoassay

“…In fact, as a result of the close phylogenetic relationship between Penicillium and Aspergillus (17), the MycAssay Aspergillus PCR shows significant cross-reactivity with most species of Penicillium, which are rarely involved in opportunistic infections in humans (26). In contrast, although GM can cross-react more frequently with antigens from Penicillium or Paecilomyces (15), we detected false-positive GM results in 3 patients with BAL fluid culture positive for Fusarium (and subsequently diagnosed with pulmonary fusariosis), according to a study described elsewhere (19).…”

Performance of Galactomannan, Beta- d -Glucan, Aspergillus Lateral-Flow Device, Conventional Culture, and PCR Tests with Bronchoalveolar Lavage Fluid for Diagnosis of Invasive Pulmonary Aspergillosis

“…that is released into the bloodstream by growing hyphae and germinating spores/ conidia. The diagnostic performance of GM testing with bronchoalveolar lavage (BAL) fluid specimens is promising, as it has higher sensitivity than that of serum testing (14). The test, however, has several limitations.…”

Molecular Detection and Species-Specific Identification of Medically Important Aspergillus Species by Real-Time PCR in Experimental Invasive Pulmonary Aspergillosis

“…Serum galactomannan (GM) and (133)-␤-D-glucan assays are FDA-approved assays for the diagnosis of invasive pulmonary aspergillosis. The measurement of galactomannan in bronchoalveolar lavage (BAL) fluid shows promise in enhancing the diagnosis of IPA (2,4,12,18).…”