Polymerase chain reaction on blood for the diagnosis of invasive pulmonary aspergillosis in cancer patients

Abstract

Aspergillus PCR on whole blood samples is highly sensitive for the detection of IPA and is predictive for IPA. The sensitivity appears to be correlated with the certainty of diagnosis as proven by tissue invasion.

Polymerase chain reaction in the diagnosis of invasive aspergillosis

“…6 Retrieving the microorganism from BAL by either culture methods or PCR is often associated with false positive results caused by colonizing presence of aspergilli in the respiratory tract. 4 Aspergillus culture and microscopy in BAL provide a sensitivity of 43% and a specificity of 100% in cases of IPA. 6 PCR in BAL has an estimated sensitivity of 67-100% and a specificity between 55 and 95%.…”

“…Polymerase chain reaction (PCR) technique has also been suggested as a mode of detecting the infection; but the diagnostic value of the PCR remains to be established in prospective studies. 4,5 In this report, an immuncompromised patient with IPA diagnosed and monitored by PCR is presented. The PCR protocol for the isolation of the DNA from the blood samples is also described.…”

Challenges and progress in setting a standard for PCR for invasive aspergillosis

“…To illustrate this, the LR of a positive test (LR+) and corresponding LR of a negative test (LR-) for a single PCR test result are shown in Figure 1. Clearly, there is a high LR+ only for the study of Raad et al [18]. The studies of Halliday et al [12•], Hebart et al [13,14], and Scotter et al [19] all yielded a high LR-but very low LR+.…”

“…This begs the question of what gave rise to these differences. Perhaps it was the patient cohort studied, as that of Raad et al [18] included patients with pulmonary infi ltrates, whereas the patient cohorts of Halliday et al Table 2 shows that there were indeed major methodologic differences, with no two studies employing the same PCR technique.…”

“…In preparing a systematic review with Carlo Mengoli of the Department of Histology, Microbiology, and Medical Biotechnology, University of Padua, Padua, Italy and Mario Cruciani from the Centre of Preventive Medicine, HIV Outpatient Clinic, Verona, Italy based on the review of Boudewijns et al [5], we identifi ed 16 prospective cohort studies of consecutive patients at high risk for invasive aspergillosis akin to phase 2 drug studies [3,6-8,9•,10,11,12•, [13][14][15][16][17][18][19][20]. All compared the results of PCR with the diagnosis made following the original defi nitions for invasive fungal disease proposed by the EORTC/MSG or, for studies reported before the publication of these criteria in 2002, comparable criteria as a reference standard [1].…”