Abstract and Introduction
Abstract
A new fungal surrogate marker, (1–3)-β-D glucan, offers a noninvasive method for the potential surveillance and diagnosis of invasive fungal infections. Invasive fungal infections have long been associated with significantly high morbidity and mortality on hematology-oncology wards and recipients of either solid-organ or hematopoietic stem cell transplantation. The diagnoses of invasive fungal infections have historically been made difficult by the need for invasive methods. (1–3)-β-D-glucan testing requires a minimally invasive sample that can be used to aid in the diagnosis of an invasive fungal infection as well as monitor the response to treatment. One disadvantage of (1–3)-β-D-glucan testing is that a positive test alone lacks sufficient sensitivity and specificity for a definitive diagnosis. While formal guidelines for the use of (1–3)-β-D-glucan testing are lacking, this chromogenic assay provides a new opportunity for testing at-risk populations. A review and recommendation for its laboratory and clinical application are provided.
Glossary
(1–3)-β-D-glucan: A polysaccharide component of the cell wall of most fungi pyrogen test. An assay used to determine if a pharmaceutical or medical device intended for human use will stimulate fever.
Introduction
Invasive fungal infections remain a significant problem in hematopoietic stem cell transplant (HSCT) and solid organ transplantation (SOT) recipients with changing epidemiologic patterns during the previous 2 decades.[1,2] Despite advances in technology and therapy, invasive fungal infections are still associated with significantly high morbidity and mortality.[3] Among SOT recipients, Candida and Aspergillus pathogens continue to be most often implicated as the cause of infections.[1] However, Aspergillus species and other filamentous molds, such as Fusarium, Scedosporium, and the Zygomycetes, are more commonly associated with invasive fungal infections in HSCT recipients.[2]
Measurement of biologic markers, such as the galactomannan Aspergillus antigen and the fungal wall component (1–3)-β-D-glucan, offers a noninvasive method for the detection of invasive fungal infections. Historically, the diagnosis of invasive fungal infections has been made difficult by the need for tissue biopsies for cultures and histological examination.4 Furthermore, clinical and radiological findings do not have sufficient diagnostic sensitivity and specificity to be helpful. This review will discuss the U.S. Food & Drug Administration (FDA) approved fungal wall component (1–3)-β-D-glucan assay and its role as a surrogate marker for invasive fungal infections.
Lab Med. 2011;42(11):679-685. © 2011 American Society for Clinical Pathology
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