Detection ofAspergillusSpecies in Blood and Bronchoalveolar Lavage Samples from Immunocompromised Patients by Means of 2‐Step Polymerase Chain Reaction: Clinical Results

Abstract

Bronchoalveolar lavage (BAL) samples from 67 patients who were at high risk for invasive aspergillosis were examined using a recently developed 2-step polymerase chain reaction (PCR) that detects </=10 fg of Aspergillus DNA in blood and BAL samples in vitro. Thirteen of these patients had PCR and diagnostic results positive for Aspergillus infection. Four patients with possible invasive aspergillosis also had positive PCR results, and the remaining 50 had negative PCR results. In addition, 907 blood samples from 218 high-risk patients were screened. Thirty-three patients with positive PCR results had invasive aspergillosis; 148 patients had PCR and diagnostic results that were negative, and 34 patients with positive PCR results had nonconclusive clinical data. Both blood and BAL testing were performed for 45 patients. All 8 patients with proven invasive aspergillosis showed concordance of positive PCR results. Our data suggest that this PCR method has possible clinical value for confirming and improving the diagnosis of invasive aspergillosis in high-risk patients.

Diagnosis of invasive fungal infections by a real-time panfungal PCR assay in immunocompromised pediatric patients

“…18,19,[26][27][28] The reported sensitivity and the NPV were moderate to high. The specificity was generally lower, but could be significantly improved by establishing the requirement of two consecutive positive PCR results as a diagnostic criterion.…”

Galactomannan testing andAspergillusPCR in same-day bronchoalveolar lavage and blood samples for diagnosis of invasive aspergillosis

“…The nested Aspergillus specific PCR assay used in this study is well established and has proven its functionality in various studies including a comparative interlaboratory study among centers from Germany and Austria. 9,38 Concerning test results from BALF it has to be kept in mind that bronchoscopy and BALF can be biased by the examiner (e.g., volume of lavage fluid). Some physicians tend to avoid or delay bronchoscopy because of the risk of bleeding in the setting of thrombocytopenia or because they consider the invasive procedure to be too strenuous for patients with wasting diseases.…”

Impact of PCR-based diagnosis of invasive pulmonary aspergillosis on clinical outcome

“…Detection of ASP DNA in BAL fluid theoretically enables early diagnosis and early guided optimal therapy that is expected eventually to improve the outcome of IPA in high-risk patients. [6][7][8][9][10][11] In our hands, the turnaround time for PCR-based detection of aspergillus DNA from BAL sampling until delivery of the results is approximately 1-2 working days, with the molecular diagnostic procedure lasting for about 6 h. This study evaluated the contribution of ASP DNA detection to the diagnostic workup of immune-compromised patients with IPA by comparing the mortality rates during two different time periods, with and without the addition of ASP PCR testing. In-hospital mortality was chosen as the outcome variable, despite the fact that nowadays the disease, especially in allogeneic BMT recipients, can present in the community long after transplantation, because in our hospital the standard of care was to admit patients suspected of having IPA, and treat them in hospital for this diagnosis, even a long time after the BMT.…”

“…1,2 Early diagnosis of IPA and administration of antifungal treatment is expected to improve outcome, but this goal is difficult to achieve as cultivation of the causative agent Aspergillus species (ASP) from respiratory secretions has poor sensitivity. [3][4][5][6][7] Deep tissue biopsy specimens are difficult to obtain in this setup because many affected patients have poor respiratory status in addition to coagulation defects. PCR-based ASP DNA detection in bronchoalveolar lavage (BAL) fluid theoretically enables earlier and more frequent diagnosis of IPA.…”