Dipstick Assay Identifies Fungal Disease Antigen

A rapid point-of-care assay is under development that could lead to early diagnosis and potentially save the lives of people stricken with fungal meningitis.

The assay detects cryptococcal antigen and will use a drop of blood from a finger-stick or a urine sample to identify immediately the presence of the disease so treatment can begin instantly, rather than having to wait for results to be processed at a laboratory.

The Lateral Flow Assay is an immunochromatographic test system for the qualitative or semiquantitative detection of Cryptococcus species capsular polysaccharide antigens (CrAg) of both Cryptococcus neoformans and C. gattii in serum and cerebrospinal fluid (CSF). The test is the CrAg Lateral Flow Assay, which is a dipstick sandwich-immunochromatographic assay. Specimens and specimen diluent are added into an appropriate reservoir, such as a test tube, and the lateral flow device is placed into the reservoir. The test uses specimen wicking to capture gold-conjugated, anti-CrAg monoclonal antibodies and gold-conjugated control antibodies deposited on the test membrane.

The assay is being developed in a joint collaboration between scientists at the University of Nevada School of Medicine (Reno, NV, USA) and Immuno-Mycologics, (IMMY; Norman, OK, USA), who have licensed the CrAg Lateral Flow Assay. The assay has received the conformance marking (CE) of the European Community, and is being field tested in Africa.

Thomas Kozel, PhD, professor of microbiology at the University of Nevada School of Medicine, said, "The ability to quickly identify mycosis in patients is expected to help in significantly reducing cryptococcal meningitis deaths in resource-limited countries such as those in sub-Saharan Africa. Cryptococcosis is a rare form of meningitis among otherwise healthy individuals, but an estimated 600,000 lives are lost to this infection each year in patients with acquired immunodeficiency syndrome (AIDS). Many of these lives could be saved through early diagnosis."

Related Links:

University of Nevada School of Medicine

Immuno-Mycologics