Advances in diagnostic testing.

Within the past decade surrogate markers have become important and reliable tools for the early diagnosis of invasive aspergillosis. Surrogate markers include the antigens galactomannan and (1 --> 3)-beta-D-glucan for which commercial assays are available, as well as fungal DNA for which experimental PCR assays have been developed. Although many clinical validation studies have been performed, the kinetics of these markers are still largely unknown. Recent studies have addressed several issues related to variables that interact with the performance of the assays, including exposure to mould-active antifungal agents and the interpretive cut-off levels. Insights gained as a result of these studies will help us to further optimize management strategies and to determine the optimal test sequence.