Evaluation of polymerase chain reaction for the presence of invasive aspergillozis in patients with haematologic malignancies

Patients who are receiving induction chemotherapy due to haematologic malignancies and patients who are under intense therapy cause of Hematopoietic Stem Cell Transplantation, have risk of Invasive Aspergillozis (IA). Diagnosis may be uncertain or delay in these group of patients because of nonspecific clinic presentation, high resolution computed tomography findings, lack of sensitivity and difficult application techniques of conventional methods. Early diagnosis can provide initial antifungal therapy accordingly reduce long hospitalization periods, high costs of therapy and most of all prevent high mortality. In this study, we investigated the performance of first commercial real-time Aspergillus Polimerase Chain Reaction (PCR) Mycassay of Myconostica and another novel commercial Aspergillus PCR assay of Qiagen with using serum samples for the IA diagnosis of patients with febrile neutropenic episodes. The study was conducted in Akdeniz University Medical Faculty Hospital, Haematology and adult stem cell transplantation units. Between January 2015 and January 2016, 168 serum samples of 41 febrile neutropenic episodes belong to 32 patients with risk of IA were tested. We also collected the demographic data and clinical characteristics which can be a risk for IA. The reference diagnosis of IA was assessed according to revised definitions of European Organization for Research and Treatment of Cancer/Mycoses Study Group (EORTC/MSG) criteria published in 2008. According to the definitions, there was no proven IA patient in our study. 21 patients were probable IA, 7 patients were possible IA and 13 patients were under the risk of IA. Artus Qiagen PCR assay had a sensitivity of 47.6%, specifity of 100%, positive and negative predictive values were 100% and 64.5%, respectively. MycAssay Aspergillus PCR assay had a sensitivity of 61.9%, specifity of 100%, positive and negative predictive values were 100% and 71.4%, respectively. Instead of the use of commercial PCR assays as a single test for IA diagnosis in serum samples from haemathologic patients in routine clinical practice, it is much more suitable as a supporting test for conducting of early diagnosis and pre-emptive therapy. Further well designed investigations with clinician correlation and multicenter comprehensive studies are required to accept PCR tests as a part of microbiological diagnostic tests for IA.