title: Analysis of performance of a PCR-based assay to detect DNA of Aspergillus fumigatus in whole blood and serum: a comparative study with clinical samples.
abstract: The performance of a real-time PCR-based assay was retrospectively analyzed (according to European Organization for Research and Treatment of Cancer/Mycosis Study Group criteria) in the samples of patients with invasive aspergillosis. A total of 711 serial samples (356 whole-blood and 355 serum samples) from 38 adult patients were analyzed. The Aspergillus fumigatus PCR assay results were positive for 89 of 356 (25%) whole-blood samples and 90 of 355 (25.35%) serum samples. Positive PCR results were seen in 29 of 31 (93.5%) patients for which serum was analyzed and in 31 of 33 (93.9%) cases with whole-blood specimens. Both blood and serum samples were available in 26 cases, and significant differences were not observed in this subgroup of cases. The average number of threshold cycles (C(T)) for positive blood samples was 37.6, and the average C(T) for serum was 37.4. The DNA concentration ranged between 2 and 50 fg per μl of sample, with average DNA concentrations of 10.2 and 11.7 fg in positive blood and serum samples, respectively (P > 0.01). The performance of this PCR-based quantitative assay was similar for both serum and blood samples. We recommend serum samples as the most convenient hematological sample to use for Aspergillus DNA quantification when serial determinations are done.
authors.affiliation: Servicio de Micología, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Ctra Majadahonda-Pozuelo, Km 2. 28220 Majadahonda (Madrid), Spain.
authors.forename: Leticia
authors.initials: L
authors.lastname: Bernal-Martínez
authors.forename: Sara
authors.initials: S
authors.lastname: Gago
authors.forename: María J
authors.initials: MJ
authors.lastname: Buitrago
authors.forename: Alicia
authors.initials: A
authors.lastname: Gomez-Lopez
authors.forename: Juan L
authors.initials: JL
authors.lastname: Rodríguez-Tudela
authors.forename: Manuel
authors.initials: M
authors.lastname: Cuenca-Estrella
mesh_terms: D000328:Adult; D001228:Aspergillosis / Q000175:diagnosis*; D001232:Aspergillus fumigatus / Q000302:isolation & purification*; D001769:Blood / Q000382:microbiology*; D006801:Humans; D025202:Molecular Diagnostic Techniques / Q000379:methods*; D009172:Mycology / Q000379:methods*; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods*; D012189:Retrospective Studies; D044967:Serum / Q000382:microbiology*