Antigen detection in the diagnosis of Invasive Aspergillosis


P.E. Verweij
JCM Accepts, 20 Feb 2008


Aspergillus species are known to release exo-antigens during growth in vitro and in vivo. Low levels of antigens may be present in body fluids of patients with invasive Aspergillus infection such as serum, urine and CSF. A number of methods have been developed and evaluated which employ antibodies directed against antigens produced by Aspergillus. These methods include latex agglutination (1), radioimmunoassay (2), ELISA inhibition (3) and sandwich ELISA (4). The detection limits for antigen of these assays are 15, 10, 4 to 5, and 1 ng/ml respectively (4). Two antigen detection kits are commercially available and have been evaluated in several institutes. The latex agglutination (LA) test (Pastorex Aspergillus, Sanofi Diagnostics Pasteur, Marnes-La-Coquette, France) employs the rat monoclonal antibody EB-A2 to detect Aspergillus galactomannan (5). This assay has been evaluated with serum mainly from patients receiving treatment for hematological malignancies and although the specificity of the LA-test was high, substantial variation in sensitivity was observed (Table 1) (1,6-12).