Putting PCR for Aspergillus through its paces (#98)
Aspergillus PCR has been around since the mid 1980’s but the techniques was left out of the EORTC/MSG definitions in 2002 and again in 2008 as the technique was neither standardized nor validated. This galvanized a group a group of scientists to convene a working group of the International Society of Human and Animal Mycology (ISHAM) “The European Aspergillus PCR Initiative” at its congress of 2006 in Paris to remedy this (www.eapcri.eu). The group comprised many of those who had developed their own PCR and had published results on its use. A steering committee was established together with a laboratory and clinical working party and the EAPCRI soon had 86 participants from 69 centres of 24 countries, including Australia. The goal was to develop a standard for Aspergillus PCR methodology and to validate this in clinical trials so that PCR could be incorporated into future consensus definitions for diagnosing IFD. The EAPCRI has achieved its aim of developing standards for Aspergillus PCR and published protocols for whole blood and serum and work on plasma is in progress. The group has also identified the critical stages Aspergillus DNA extraction and published a protocol to ensure optimal performance. There is also a specific collaboration with The University of Texas Health Science Center at San Antonio and the Invasive Aspergillosis Animal Models (IAAM) to evaluate the proposed standard in rodents infection models. A calibrator is also being developed that will aid in an External Quality Control programme to enable all laboratories to evaluate performance in using PCR to detect Aspergillus. To this end EAPCRI is working closely with Quality Control for Molecular Diagnostics (QCMD) through an External Quality Assessment (EQA), Proficiency Testing (PT) and other quality initiatives (www.qcmd.org). The EAPCRI is also repeating a systematic review of Aspergillus PCR within the Cochrane Collaboration to assess the impact of the standardized Aspergillus PCR protocols on diagnostic utility. Diagnostic validity is being explored in two ongoing clinical trials, one of the European Organization for Research and Treatment of Cancer (www.EORTC.org), the other the AmBiguard prophylactic study undertaken by Gilead Sciences. The achievements and activities if successful should lead to a standard for Aspergillus PCR methodology and allow it to be incorporated into future EORTC/MSG consensus definitions for diagnosing IFD.