Evaluation of the Wako™ β-D-Glucan assay in Patient Serum for the Diagnosis of Invasive Aspergillosis.

F. Hegarty

Author address: 

Microbiology, Mater Misericordiae University Hopsital, Dublin, Ireland

Abstract: 

Objectives: Invasive Aspergillosis is a fungal disease that can carry a high morbidity and mortality, especially in those patients who are immunosuppressed. Early diagnosis of Invasive Aspergillosis (IA) is key to implementing early treatment and improve patient prognosis. Currently in MMUH, serum β-D-Glucan (BDG) is available as an external referral test only (average TAT 109.5 days). Expanding our current repertoire of tests to include BDG, would greatly aid in the early diagnosis of IA. Delay or misdiagnosis of IA can result in drug toxicity due to inappropriate treatment, high medical expenses and mortality. Given the complexity of invasive fungal diseases a number of tests are required for correct diagnosis. Therefore implementation of another test that can quickly and accurately aid in the diagnosis of IA would have great benefits for overall patient care, whilst limiting unnecessary use of antifungal therapy within the hospital.

Aim: To evaluate the Wako™ β-D-Glucan assay in the laboratory and its’ implications for clinical practice. To assess the contribution this test can make to patient care

Methods: Fifty-one random patient samples (serum) were used to complete this pilot study. Samples included ICU, lung transplant and haematology patients. Positive and negative controls were included weekly. The Wako™ β-D-Glucan was evaluated as per the manufacturer’s guidelines

Results: The results obtained from the BDG were compared to external referral results. They were also analysed in conjunction with previous microbiological cultures, galactomannan, OLM™ lateral flow device calcofluor/KOH results, histological specimens, radiological imaging and clinical details where applicable. EORTC criteria were used to categorise patients into proven, probable or possible IA. BDG results demonstrated 83% sensitivity and 100% specificity as well as a positive predictive value of 100% and a negative predictive value of 88%.

Conclusion: Based on results of this study, Wako™ β-D-Glucan will be introduced in MMUH, for patients with suspected IA, or those severely immune-suppressed.

2019

abstract No: 

P320

Full conference title: 

9th Trends in Medical Mycology Conference 2019
    • TIMM (2019)