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

The mortality rate of 60-90% in invasive pulmonary aspergillosis (IPA) is partly explained by diagnostic delay due to the limitation of current diagnostic tests. We assessed the influence of Aspergillus species (ASP) DNA detection by PCR from bronchoalveolar lavage (BAL) fluid, a new tool for diagnosing IPA, on the outcome of this disease in immune-compromised patients. The study population comprised 107 consecutive patients with hematological malignancies from a single medical center with IPA diagnosed between 1998 and 2005. Clinical variables and mortality rates were compared between two groups diagnosed according to traditional criteria without and with PCR-based ASP DNA detection in BAL fluid. The overall mortality rate during the study period was 38.3%. The addition of PCR to the diagnostic criteria shifted 31 patients from possible to probable IPA. Patients diagnosed with probable IPA according to traditional microbiological methods had significantly higher mortality rates compared to their counterparts who had in addition a PCR-based diagnosis (80 vs 35.6%, P=0.003). This study demonstrates that PCR-based ASP DNA detection for a diagnosis of IPA from BAL fluid has a significant effect on the outcome of patients with IPA, probably related to earlier diagnosis.