Noninvasive Testing and Surrogate Markers in Invasive Fungal Diseases

The morbidity and mortality of invasive fungal diseases has fostered interest in surrogate biomarkers. These are used for diagnosis and may convey prognostic information. We review current evidence for the use of biomarkers for invasive fungal infections. Invasive fungal infections continue to increase as at-risk populations expand. The high associated morbidity and mortality with fungal diseases mandate the continued investigation of novel antifungal agents and diagnostic strategies that include surrogate biomarkers. Biologic markers of disease are useful prognostic indicators during clinical care, and their use in place of traditional survival end points may allow for more rapid conduct of clinical trials requiring fewer participants, decreased trial expense, and limited need for long-term follow-up. A number of fungal biomarkers have been developed and extensively evaluated in prospective clinical trials and small series. We examine the evidence for these surrogate biomarkers in this review and provide recommendations for clinicians and regulatory authorities.