title: β-D-Glucan and Candida albicans germ tube antibody in ICU patients with invasive candidiasis.
abstract: OBJECTIVE
  To assess the performance of (1→3)-β-D-glucan (BDG) and Candida albicans germ tube antibody (CAGTA) for the diagnosis of invasive candidiasis (IC) in a prospective cohort of 107 unselected, non-neutropenic ICU patients.
  
  
  METHODS
  BDG (cutoff positivity ≥80 pg/mL) and CAGTA (cutoff positivity ≥1/160) assays were performed twice a week. Confounding factors included amoxicillin-clavulanate and piperacillin-tazobactam treatments, recent surgery, Gram-positive bloodstream infection, renal replacement therapy, and enteral nutrition. Patients were classified as neither colonized nor infected (n = 29), Candida spp. colonization (n = 63) (low grade, n = 32; high grade, n = 31), and invasive candidiasis (IC) (n = 15).
  
  
  RESULTS
  BDG levels were higher in patients with IC and high-grade colonization than in the remaining groups (p = 0.012), and two consecutive measurements ≥80 pg/mL discriminated IC from the remaining groups (sensitivity 80%, specificity 75.7%). For the discrimination between IC and Candida spp. colonization, the AUC for the maximum value of BDG was 0.667 (95% CI 0.544-0.790) and for the maximum value of CAGTA 0.545 (95% CI 0.395-0.694). Significant changes of BDG and CAGTA kinetics in IC patients treated with antifungals were not observed. In patients neither colonized nor infected or with low-grade Candida spp. colonization, none of the confounding factors was associated with a significant increase in BDG positivity.
  
  
  CONCLUSIONS
  Two consecutive BDG levels ≥80 pg/mL allowed discrimination among IC and high-grade colonization. Systemic antifungal therapy could not be monitored with biomarker kinetics, and BDG levels were not subject to interference by confounding factors in either colonized or infected patients or with low-grade colonization.
authors.affiliation: Clinical Unit of Microbiology and Infectious Diseases, Hospital Universitario de Valme, Universidad de Sevilla, Sevilla, Spain.
authors.forename: Estrella
authors.initials: E
authors.lastname: Martín-Mazuelos
authors.forename: Ana
authors.initials: A
authors.lastname: Loza
authors.forename: Carmen
authors.initials: C
authors.lastname: Castro
authors.forename: Desirée
authors.initials: D
authors.lastname: Macías
authors.forename: Ismail
authors.initials: I
authors.lastname: Zakariya
authors.forename: Pedro
authors.initials: P
authors.lastname: Saavedra
authors.forename: Sergio
authors.initials: S
authors.lastname: Ruiz-Santana
authors.forename: Elena
authors.initials: E
authors.lastname: Marín
authors.forename: Cristóbal
authors.initials: C
authors.lastname: León
mesh_terms: D000328:Adult; D000368:Aged; D000908:Antibodies, Fungal / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D002176:Candida albicans / Q000276:immunology*; D058365:Candidiasis, Invasive / Q000175:diagnosis*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D013030:Spain; D047071:beta-Glucans / Q000097:blood*
chemical_list: D000908:Antibodies, Fungal; D015415:Biomarkers; D047071:beta-Glucans