Evaluation of a (1→3)-β- d -Glucan Assay for Diagnosis of Invasive Fungal Infections

Abstract

The Fungitell assay (Associates of Cape Cod, Inc.) is a commercial test that detects (1-3)-␤-D-glucan (BG) and is intended for diagnosis of invasive fungal infections. To evaluate the Fungitell assay, we tested serum and plasma samples from healthy blood donors and from patients with blood cultures positive for yeast or bacteria. All 36 blood donors were BG negative, and 13 of 15 candidemic patients were BG positive. Of 25 bacteremic patients, 14 (10 with gram-positive bacteremia) were BG positive. One of the latter patients with Staphylococcus aureus bacteremia also had invasive candidiasis, based on histological findings in a tissue biopsy; therefore, the BG result was a true positive. The sensitivity, specificity, and positive and negative predictive values of the Fungitell assay, by patient, for these three groups were 93.3%, 77.2%, 51.9%, and 97.8%, respectively. We also performed the Fungitell assay on sera that had been tested for Aspergillus galactomannan or Histoplasma antigen. All six Histoplasma antigen-positive patients and 31 of 32 Aspergillus galactomannan-positive patients were also BG positive. BG results for the 10 Histoplasma antigen-negative and the 32 Aspergillus galactomannan-negative patients varied, but we were unable to confirm many of the results. Between-run coefficients of variance (CVs) for the assay ranged from 3.2% to 16.8%; within-run CVs were <4.8%. The correlation coefficient for an interlaboratory reproducibility study was 0.9892. Concentrations of hemoglobulin, bilirubin, and triglycerides that caused 20% interference were 588, 72, and 466 mg/dl, respectively. Our results suggest that the Fungitel assay may be most useful for excluding invasive fungal infection.

Value of β-d-glucan and Candida albicans germ tube antibody for discriminating between Candida colonization and invasive candidiasis in patients with severe abdominal conditions

“…2 Prediction rule for the diagnosis of invasive candidiasis (IC) in nonneutropenic adult critically ill patients with severe abdominal conditions. Each terminal node shows the probability of the predicted event intravenous immunoglobulins, albumin, coagulation factors, and plasma protein fractions [27][28][29]. In addition, Pickering et al [29] showed in a cross-contamination experiment that excess manipulation of a sample can result in its contamination with BDG.…”

“…Each terminal node shows the probability of the predicted event intravenous immunoglobulins, albumin, coagulation factors, and plasma protein fractions [27][28][29]. In addition, Pickering et al [29] showed in a cross-contamination experiment that excess manipulation of a sample can result in its contamination with BDG. In our IC patients, 12 (38.7 %) had renal replacement therapy, 3 (9.6 %) had Gram-positive bacteremia, and 3 (9.6 %) received betalactam antibiotics.…”

Diagnostic potential of nested PCR, galactomannan EIA, and Beta-D-glucan for invasive aspergillosis in pediatric patients

“…Furthermore, some conditions such as exposure to certain gauzes [25], taking several antibiotics at high concentrations [26], using certain hemodialysis cellulose membranes [27], and receipt of albumin or immunoglobulin products, plasma proteins or coagulation factors [28] may contribute to a greater yield of false positive. False positives by BDG may also be obtained by a variety of other reasons including "bacteremia, hemolysis; intravenous administration of treatment with certain medications; exposure to cotton bandages; heat stroke; and unknown causes" [29,30]. The use of different species of horseshoe crab as a source of reagent by the manufacturers creates different cutoff values.…”

How effective is beta glucan test in early diagnosis of invasive fungal infection in patient with hematologic malignancy?

“…This antigen can be detected in serum and other body fluids. It has been shown that BG can be positive before the clinical symptoms and radiological signs [14][15][16][17][18][19][20]. Various studies show that this test's sensitivity and specifity varies between 55-95% and 77-96%, respectively [14][15][16][17][18][19][20].…”