Aspergillus PCR in Bronchoalveolar Lavage Fluid for the Diagnosis and Prognosis of Aspergillosis in Patients With Hematological and Non-hematological Conditions

Objectives: We evaluated the usefulness of an Aspergillus fumigatus quantitative PCR assay performed in bronchoalveolar lavage fluid (BAL) for the diagnosis and prognosis of both invasive and non-invasive aspergillosis. Methods: This four-year retrospective study involved 613 at-risk patients who had either haematological disorders or other immunosuppressive conditions, notably solid organ transplants. Thirty-five patients had proven/probable aspergillosis and thirteen had chronic non-invasive aspergillosis. We compared PCR, galactomannan index and mycological analysis of BAL. Results: For invasive aspergillosis, PCR performed in BAL yielded 88.6% sensitivity and 95.5% specificity. Comparatively, galactomannan index and mycological examination yielded only 56.3% and 63.6% sensitivity and 97.6% and 94.5% specificity, respectively. Considering the 13 chronic aspergillosis cases, PCR, galactomannan index and mycological examination yielded 76.9%, 15.4% and 84.6% sensitivity and 92.2%, 94.9% and 93% specificity, respectively. Fungal load in BAL evaluated by PCR was able to discriminate between aspergillosis and contamination, but not between invasive and non-invasive forms. Finally, fungal load was predictive of 90-day mortality, with 23.1% mortality for patients with less than 500 copies/mL versus 68.4% for patients above that cut-off (p<0.05). Conclusion: Our results indicate that Aspergillus PCR in BAL is of particular interest for both the diagnosis and the prognosis of invasive aspergillosis. It is likewise an interesting tool for the diagnosis of non-invasive forms.