Evaluation of the combined use of galactomannan antigen and Aspergillus DNA real-time PCR detection in laboratory diagnosis of invasive aspergillosis among haematological patients

Georgia Vrioni *1, Constantinos Tsiamis 1, Maria Mavrouli 1, Kalliopi Theodoridou 1, Violetta Kapsimali 1, Athanassios Tsakris 1

Author address: 

1 National and Kapodistrian University of Athens, Department of Microbiology, Medical School, Athens, Greece

Abstract: 

Background: Diagnosis of invasive aspergillosis (ΙΑ) still remains a critical issue among hematological patients. According to the guidelines released by the European Organization for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group and the National Institute of Allergy and Infectious Diseases Mycoses Study Group (EORTC/MSG), the serological detection of galactomannan (GM) has been considered as the mycological diagnostic standard method. Nevertheless, Aspergillus DNA detection has not been included in the guidelines, due to the lack of standardization and validation.

Materials/methods: In the current study the combined use of Aspergillus GM and Aspergillus DNA detection was evaluated as a useful practice for diagnosis of suspicious invasive IA. The study includes 1,041 samples by 454 patients with hematological malignancies (59 adults and 395 children) from five hematologic units of tertiary care Greek hospitals during 2012-2018. The measurements were made by GM immunoenzymatic method Platelia Aspergillus (Bio-Rad, Hercules, CA) and PCR Aspergillus (Standard Real-Time PCR detection kit for Aspergillus, PrimerDesing). In the immunoenzymatic method, positive samples were considered those with a cut-off index ≥0.5 and ≥1.0 in serum and bronchoalveolar lavage (BAL), respectively.

Results: GM and PCR-Aspergillus DNA investigation showed that 44 from 454 patients (9 from 59 adults and 35 from 395 children) were positive for IA. 17 patients (6 adults and 11 children) were found positive using both assays (GM+/PCR+), 2 adults and 16 children were positive by GM only (34 sera & 1 BAL), while 1 adult and 8 children were positive by PCR only (12 sera) (Table). The results’ agreement of GM(+)/PCR(+) and GM(-)/PCR(-) were found in 427 patients and 993 samples (94% of the total patients and 95% of the total samples). Respectively, discrepant results were found in only 27 patients (48 samples; 4,6% of total), in which the positive result in any of the two methods was evaluated as true positive, in conjunction with the clinical and radiological findings.

Conclusions: Our findings indicate that the combination of GM-antigen and PCR-Aspergillus DNA detection could be an important laboratory tool for the diagnosis of IA in conjunction with clinical, radiological and other laboratory findings of the patient.

Presenter email address: [email protected]

2020

abstract No: 

6272

Full conference title: 

European Congress of Clinical Microbiology and Infectious Diseases 2020
    • ECCMID 30th (2020)