title: Serum glucan levels are not specific for presence of fungal infections in intensive care unit patients.
abstract: Fungal infections in the critically ill patient are difficult to diagnose and are associated with a high mortality rate. A major obstacle to managing fungal infection is the lack of a reliable clinical assay that will rapidly identify patients with fungal sepsis. Glucans are polymers of glucose that are found in the cell wall of fungi and certain bacteria. Glucans are also released from the fungal cell wall into the extracellular milieu. Several studies have reported that detection of fungal glucan in serum or plasma is useful in the diagnosis of mycoses. However, recent studies have questioned the clinical utility of this assay. In this study, we examined serum glucan levels in intensive care unit (ICU) patients and attempt to correlate serum glucan levels with the presence of fungal infection. Following attainment of informed consent, serum was harvested from 46 ICU patients with confirmed fungal infections, confirmed bacterial infections, or no evidence of infection. Sera from eight healthy volunteers served as control. Serum glucan was assayed with a glucan-specific Limulus assay. Serum glucan levels were increased (69.6 +/- 17 pg/ml; P < 0.001) in ICU patients versus the normal (11.5 +/- 1.3 pg/ml) and noninfected ICU (27.4 +/- 17 pg/ml) controls. However, serum glucan levels were not different in patients with confirmed fungal infections versus those with confirmed bacterial infections. Thus, serum glucan levels did not show a correlation with the presence of fungal infections and do not appear to be specific for fungal infections. However, the assay may be useful as a negative predictor of infection.
authors.affiliation: Departments of Surgery and Medical Education, James H. Quillen College of Medicine, East Tennessee State University, Johnson City, Tennessee 37614, USA.
authors.forename: Justin
authors.initials: J
authors.lastname: Digby
authors.forename: John
authors.initials: J
authors.lastname: Kalbfleisch
authors.forename: Andy
authors.initials: A
authors.lastname: Glenn
authors.forename: Angie
authors.initials: A
authors.lastname: Larsen
authors.forename: William
authors.initials: W
authors.lastname: Browder
authors.forename: David
authors.initials: D
authors.lastname: Williams
mesh_terms: D005936:Glucans / Q000097:blood*; D006801:Humans; D007362:Intensive Care Units; D009181:Mycoses / Q000097:blood* / Q000175:diagnosis*; D011446:Prospective Studies; D012680:Sensitivity and Specificity
chemical_list: D005936:Glucans