title: Diagnostic value of immunoglobulin G antibodies against Candida enolase and fructose-bisphosphate aldolase for candidemia.
abstract: BACKGROUND
  The yeast Candida is one of the most frequent pathogens isolated from bloodstream infections and is associated with significant morbidity and mortality. Problems with clinical and microbiological diagnosis of invasive candidiasis (IC) have prompted the development of non-culture-based laboratory methods. Previous reports suggest that serological detection of antibodies might be useful for diagnosing systemic candidiasis.
  
  
  METHODS
  Diagnosis of IC using antibodies against recombinant Candida albicans enolase (Eno) and fructose-bisphosphate aldolase (Fba1) was evaluated. Using recombinant Eno and Fba1 as coating antigens, enzyme-linked immunosorbent assays (ELISAs) were used to analyze sera from patients with candidemia (n = 101), Candida colonization (n = 50), bacteremia (n = 84), invasive aspergillosis (n = 40); and from healthy controls (n = 200).
  
  
  RESULTS
  The results demonstrated that ELISA detection of anti-Eno and anti-Fba1 IgG distinguished IC from other pathogenic infections in patients and healthy individuals. The sensitivity, specificity, and positive and negative predictive values were 72.3%, 94.7%, 78.5% and 93% for anti-Eno, and 87.1%, 92.8%, 76.5% and 96.4% for anti-Fba1 antibodies, respectively. Combining these two tests improved sensitivity up to 90.1% and negative predictive value up to 97.1%, with specificity and positive predictive values of 90.6% and 72.2%. The tests were specific to the Candida genus and antibody titers were higher for candidemia patients than for controls. Positive antibody tests were obtained before blood culture results for 42.2% of patients for anti-Eno and 51.1% for anti-Fba1.
  
  
  CONCLUSIONS
  These data suggest that tests that detect IgG antibodies against Candida enolase and fructose-bisphosphate aldolase, especially when used in combination, could be a powerful tool for diagnosing IC.
authors.affiliation: Laboratory of Molecular Biology, Institute of Medical Laboratory Sciences, Jinling Hospital, School of Medicine Nanjing University, Nanjing 210002, P R China. njlifq@163.com
authors.forename: Fang-Qiu
authors.initials: FQ
authors.lastname: Li
authors.forename: Chun-Fang
authors.initials: CF
authors.lastname: Ma
authors.forename: Li-Ning
authors.initials: LN
authors.lastname: Shi
authors.forename: Jing-Fen
authors.initials: JF
authors.lastname: Lu
authors.forename: Ying
authors.initials: Y
authors.lastname: Wang
authors.forename: Mei
authors.initials: M
authors.lastname: Huang
authors.forename: Qian-Qian
authors.initials: QQ
authors.lastname: Kong
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000908:Antibodies, Fungal / Q000097:blood*; D000946:Antigens, Fungal / Q000276:immunology; D002175:Candida / Q000201:enzymology / Q000276:immunology* / Q000302:isolation & purification; D058387:Candidemia / Q000175:diagnosis* / Q000276:immunology; D016022:Case-Control Studies; D015331:Cohort Studies; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005260:Female; D005634:Fructose-Bisphosphate Aldolase / Q000276:immunology*; D005656:Fungal Proteins / Q000276:immunology*; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood*; D008297:Male; D008875:Middle Aged; D010751:Phosphopyruvate Hydratase / Q000276:immunology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012698:Serologic Tests / Q000379:methods; D018709:Statistics, Nonparametric
chemical_list: D000908:Antibodies, Fungal; D000946:Antigens, Fungal; D005656:Fungal Proteins; D007074:Immunoglobulin G; D005634:Fructose-Bisphosphate Aldolase; D010751:Phosphopyruvate Hydratase