Ergosterol-based test for the diagnostics of fungal infections

DESCRIPTION (provided by applicant): Systemic fungal infection (SFI) is a life threatening disease affecting growing numbers of immunocompromised and other patients. The current gold standard diagnostic method for SFI culturing of affected tissue or bloo d requires days to weeks and fails in over half of the tests. Diagnostic alternatives on the market generally have low sensitivities and/or lack specificity (suffer from false-negative and false-positive values). Physicians treating fungal infection want to know the species responsible for the disease but they unanimously agree that there is an urgent need for a quick and reliable, sensitive and specific, yes/no diagnostic for SFI in order to start or not start treatment and save lives. Ergosterol is an a ccepted biomarker for fungi and yeasts and is absent in humans and animals. It thus represents an ideal SFI diagnostic analyte and, if quantified, a potential tool to monitor disease treatment as well as advance fungal disease biomedical research. Ergoster ol has not been used for SFI diagnosis, probably because it is not immunogenic and no assay suitable for clinical use is available. Semorex has developed a direct approach for targeting ergosterol, involving selective chemical tagging of ergosterol without tagging closely similar substances. In preliminary research, Semorex established (via a proprietary HPLC assay for fluorescently labelled ergosterol) the proof-of-principle for this approach using clinical samples and several fungal strains. During Phase I larger numbers of clinical samples from patients with and without fungal disease will be tested in order to establish the generality or limitations of this approach. In addition, the chemistry that facilitates the HPLC analysis will be adapted for the de velopment of a novel lateral flow device (LFD, or strip assay) based upon a molecularly imprinted polymer (MIP) instead of an antibody to bind the tagged ergosterol adduct. An LFD assay based upon MIPs will be robust, long-lived and inexpensive. If success ful, the anticipated LFD product (which will be developed with an identified manufacturing and marketing partner during Phase II) should compete well with antibody-based (insufficient sensitivity) or PCR-based (expensive and difficult to perform) products for SFI assay and, we believe, revolutionize SFI testing. Furthermore, we anticipate that this device will pave the way for other MIP-based robust and high-performance LFDs. PUBLIC HEALTH RELEVANCE: This proposal describes a new method for the rapi d and accurate diagnosis of systemic fungal infection, an increasingly common disease taking the lives of many patients. Current methods are slow and/or inadequate. Preliminary results indicate that the new approach, which detects ergosterol, a molecule th at is present in fungus cell walls and is absent in humans and animals, may answer physicians' urgent need for a quick, reliable yes/no answer when treating patients having potential fungal disease.