Clinical Validation of a Multiplex Real-Time PCR Assay for Detection of Invasive Candidiasis in Intensive Care Unit Patients

J Antimicrob Chemother. 2014 Nov;69(11):3134-41. doi: 10.1093/jac/dku225. Epub 2014 Jun 25.

Abstract

Background: New techniques, such as those based on multiplex quantitative real-time PCR (MRT-PCR), can improve the detection of invasive candidiasis (IC).

Methods: We prospectively studied 63 intensive care unit patients with suspected IC and 40 healthy controls. Blood cultures and MRT-PCR were performed at day 0 and +2, +7, +14 and +21 days in all patients. In addition, β-d-glucan (BDG) and Candida albicans germ tube antibody (CAGTA) were quantified.

Results: IC was confirmed in 27 patients. Colonization was significantly higher in patients with IC (96% versus 64%, P = 0.002). The sensitivity, specificity, positive predictive value and negative predictive value of MRT-PCR for the diagnosis of IC were 96.3%, 97.3%, 92.8% and 98.7%, respectively. The positive predictive value and specificity were significantly higher for MRT-PCR than for BDG and CATGA. MRT-PCR performed very well, especially in deep-seated IC (sensitivity 90.9% versus 45.4% for blood culture; P = 0.06). As regards the most appropriate clinical sample for DNA amplification, in this study whole blood and serum presented similar results.

Conclusions: MRT-PCR appears to be a useful test for confirming a diagnosis of IC in critically ill patients, especially in those with deep-seated disease. Its high sensitivity and positive predictive value make it a much more efficient tool for the management of IC than other diagnostic procedures and clinical scores.

Keywords: CAGTA; Candida; PCR; β-d-glucan.

Publication types

  • Research Support, Non-U.S. Gov't
  • Validation Study

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Candidiasis, Invasive / blood*
  • Candidiasis, Invasive / diagnosis*
  • Child
  • Child, Preschool
  • Female
  • Humans
  • Infant
  • Intensive Care Units / standards*
  • Male
  • Middle Aged
  • Real-Time Polymerase Chain Reaction / standards*
  • Young Adult