(1–3)-β-D-Glucan Assay: A Review of its Laboratory and Clinical Application

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.Keywords: (1-3)-β-D glucan, beta glucan assay, invasive fungal infections After reading this article, readers should be able to discuss what (1-3)-β-D glucans are, how they are detected in clinical biological samples, the evidence to support laboratory testing and monitoring, the limitations of testing, and the appropriate clinical setting for testing.Microbiology 71103 questions and corresponding answer form are located after this CE Update on page 686.

Comparative sensitivity of 1,3 beta‐D‐glucan for common causes of candidaemia in South Africa

“…An examination of published literature did not generate similar data and should be monitored prospectively. Overall, the data from our study are important due to the large sample size compared to many previously published studies …”

“…In summary, sensitivity appears to vary in different clinical settings, and a major cause of poor specificity is glucan content in other products. A recent meta‐analysis of the diagnostic accuracy of the BDG assay establishes a specificity of 81% (95% CI 80%‐83%) . One of the cited limitations of the assay is the difference in sensitivity between species of Candida, with particular reference to lower sensitivity for C parapsilosis .…”

“…This study was undertaken with the following aims: (a) to assess the overall sensitivity of the BDG assay for candidaemia, (b) to determine the species‐specific sensitivity, including for C auris , in comparison to the gold standard of blood cultures, (c) to determine the sensitivity of the assay in patient populations at high risk of candidaemia (neonates and infants in ICU and high‐care units, patients in adult ICU's and adult and paediatric oncology patients (both haematological and solid organ), (d) to determine if the BDG assay is able to detect candidaemia prior to blood culture collection and (e) to determine when the BDG result was available in relation to the blood culture bottle flagging positive …”

<i>Penicillium marneffei</i> Infection with β-D-glucan Elevation: A Case Report and Literature Review

“…Glucans are a major constituent of the cell walls of pathogenic fungi (with the exceptions of the Mucor, Rhizopus, Blastomyces dermatitidis, and Cryptococcus species) (15). To our knowledge, there are several case reports that have noted the elevation of serum BDG levels in patients with PMI (5-7, 10, 11, 16-19).…”

Management of sepsis: from evidence to clinical practice

“…18 The 1,3-b-D-glucan is a Candida cell wall component and in case of invasive candidiasis there will be high blood concentration of it. This test is not specific for Candida, but it can be positive in case of various fungal infections 19 (invasive Aspergillosis, Pneumocystis jirovecii pneumonia) with a high predictive negative value. 20 In case of invasive fungal infections, a high concentration of 1,3-b-D-glucan showed a good diagnostic capacity both in non-neutropenic patients 21 (sensitivity 80-90% in case of candidiasis) and in neutropenic patients.…”