[Specific antigens and antibodies in invasive aspergillosis].

Early diagnosis of invasive aspergillosis is of utmost importance but difficult to achieve. Serological methods were developed mainly because all the other diagnostic approaches had major drawbacks. The detection of antibodies against Aspergillus antigens provided little interesting information, since anti-Aspergillus antibodies were commonly found in healthy people, while, on the other hand, immunocompromised patients often failed to raise antibodies. Several groups of investigators showed that the detection in serum or urine by RIA or ELISA of Aspergillus antigens, was a highly specific indication of invasive disease. The sensitivities of the techniques, however, were moderate, partially due to the low antigen concentrations and the transient character of antigenemia. The only commercially available test is a latex agglutination test detecting 15 ng/ml galactomannan. It has a high specificity but reported sensitivities varied between 42% and 94.7%. Results with an experimental double-sandwich ELISA detecting about 1 ng/ml galactomannan suggest that the improvement of detection limit also greatly increases the clinical value of the test: patients become and remain positive 2 to 10 weeks earlier. If these results are confirmed, antigen detection could become a essential element in the management of an immunocompromised patient population.