Diagnosing and monitoring of invasive aspergillosis during antifungal therapy by polymerase chain reaction: an experimental study in mice

This study evaluated the value of polymerase chain reaction (PCR) for diagnosing and monitoring of invasive aspergillosis during amphotericin B therapy. PCR, microscopy and culture of tissues samples (n = 126) and blood samples (n = 78) of experimentally infected mice (n = 42) were performed. The PCR results of treated were compared to those of untreated animals; Aspergillus fumigatus and A. terreus were used in this study. In the amphotericin B treated group the sensitivities of PCR, microscopic examination and culture of the various tissues were 69, 58, and 53%, respectively; the specificities of all examinations were 100%. In the untreated group the sensitivities of PCR, microscopic examination, and culture were 72, 64, and 57%, respectively; the specificities of all examinations were 100%. The 78 blood samples taken from mice under therapy were tested by PCR over a period of 8 days following Aspergillus infection. The test sensitivity was 77%, the specificity 46%, the positive predictive value 59%, and the negative predictive value 67%. In the untreated group the sensitivity was 92%, the specificity 46%, the positive predictive value 63%, and the negative predictive value 86%. The results suggest that this PCR method has possible clinical value for improving the diagnosis of invasive Aspergillus infection. Monitoring of blood under antifungal therapy is not recommended. (C) 2003 Elsevier Inc. All rights reserved.