Clinical performance of a commercial real-time PCR assay for Aspergillus DNA detection in serum samples from high-risk patients: comparison with a galactomannan enzyme immunoassay

Abstract

We investigated the clinical performance of a polymerase chain reaction (PCR)-based commercial platform, the Myconostica MycAssay™ Aspergillus (MAP), for fungal DNA detection in the serum of patients at risk of invasive aspergillosis (IA). Sixty-four hospitalized patients were prospectively enrolled and a total of 71 different episodes were investigated (30 episodes were clinically/microbiologically classified as IA and 41 as control episodes). When MAP was compared to the galactomannan (GM) assay, no significant differences were found in terms of sensitivity (46.7% vs. 50.0%), specificity (97.6% vs. 95.1%), positive predictive value (PPV) (93.3% vs. 88.2%), and negative predictive value (NPV) (71.4% vs. 72.2%). The corresponding areas under the curve (AUC) of the receiver operating characteristic (ROC) curves were also superimposable. Overall, because of the good agreement between the two assays and considering the high specificity and PPV of the MAP, we suggest the use of this PCR-based platform as a second-level examination for the evaluation of clinically undefined cases where culture or GM have provided positive results.

Diagnosis of invasive fungal diseases in haematology and oncology: 2018 update of the recommendations of the infectious diseases working party of the German society for hematology and medical oncology (AGIHO)

“…However, it remains unclear whether SeptiFast ® will be available in the future. Similarly, the PCR platform Myconostica MycAssay ™ Aspergillus (MAP) was found to be equally sensitive and specific as compared to Aspergillus GM in high‐risk haematological patients …”

Invasive mould infections in solid organ transplant patients: modifiers and indicators of disease and treatment response

“…They concluded that the combination of different biomarkers and test, combined with CT scan results, could be beneficial to improve diagnostic specificity, sensitivity and, in particular, negative predictive values. Other authors have recommended similar strategies, combining results from the lateral-flow device (LFD) test and PCR [56], LFD and GM tests [48], and PCR and GM test [44,45,57]. These studies included only few SOT patients, but the results suggest that the combined use of several biomarkers and clinical parameters could provide a better diagnostic power also in SOT patients with suspected IMI.…”

The pathogenicity ofAspergillus fumigatus, drug resistance, and nanoparticle delivery

“…More recently, a PCR commercial assay (MycAssay™ Aspergillus, Myconostica) became available for the diagnosis of fungal DNA in the serum and bronchoalveolar lavage fluids of patients at risk of IA. Overall, PCR-based assays have advantages over the galactomannan assay, namely detection at the species level, where timing is critical (hours vs. days), provides higher specificity and (or) sensitivity, and when low fungal levels are present (Guinea et al 2013;Orsi et al 2015;Pini et al 2015;Torelli et al 2011). Unfortunately, it requires more expensive equipment, false positives and negatives through cross-reactivity can be generated, it involves rigorous standardization and validation methods, and PCR inhibitors can interfere with the results (Steinbach 2013;Morton et al 2017).…”