SPECIAL REPORT ECIL-3 classical diagnostic procedures for the diagnosis of invasive fungal diseases in patients with leukaemia MC Arendrup 1 , J Bille 2 , E Dannaoui 3 , M Ruhnke 4 , C-P Heussel 5 and C Kibbler 6 1 Unit of Mycology and Parasitology, Microbiological Surveillance and Research, Statens Serum Institut, Copenhagen, Denmark; 2 Department of Laboratory Medicine, Institute of Medical Microbiology, University Hospital, Lausanne, Switzerland; 3 Universite´ Paris Descartes, Faculte´de Me´decine, AP-HP, Hoˆpital Europe´en Georges Pompidou, Unite´de Parasitologie—Mycologie, Paris, France; 4 Division Oncology/Haematology, Department of Medicine, Charite´Universita¨tsmedizin, Berlin, Germany; 5 Diagnostic and Interventional Radiology with Nuclear Medicine, Chest Clinic at University Hospital Heidelberg, Heidelberg, Germany and 6 Centre for Clinical Microbiology, University College London and Department of Medical Microbiology, Royal Free Hospital NHS Trust, London, UK Invasive fungal diseases (IFDs) continue to cause considerable morbidity and mortality in patients with haematological malignancy. Diagnosis of IFD is difficult, with the sensitivity of the gold standard tests (culture and histopathology) often reported to be low, which may at least in part be due to sub- optimal sampling or subsequent handling in the routine microbiological laboratory. Therefore, a working group of the European Conference in Infections in Leukaemia was convened in 2009 with the task of reviewing the classical diagnostic procedures and providing recommendations for their optimal use. The recommendations were presented and approved at the ECIL-3 conference in September 2009. Although new serological and molecular tests are examined in separate papers, this review focuses on sample types, microscopy and culture procedures, antifungal susceptibility testing and imaging. The performance and limitations of these procedures are discussed and recommendations are provided on when and how to use them and how to interpret the results. Bone Marrow Transplantation (2012) 47, 1030–1045; doi:10.1038/bmt.2011.246; published online 9 January 2012 Keywords: invasive fungal disease; diagnostics; imaging; susceptibility; microscopy; culture Introduction Invasive fungal diseases (IFDs) continue to cause considerable morbidity and mortality in patients with haematological malignancy. 1–5 Diagnosis of IFD is difficult, with the sensitivity of the gold standard tests (culture and histopathology) often reported to be low. 6 Therefore, physicians frequently rely on a constellation of clinical signs, imaging, culture, histopathology and adjunctive tests to establish a diagnosis. 7,8 Many of the classical diagnostic procedures found in the modern mycology laboratory are based on methods in use since the early days of the specialty, refined through experience rather than through controlled comparative studies. However, given the difficulty of diagnosing IFD and the increasing relevance of knowing the species and antifungal susceptibility of the causative organisms, it is important to optimize their isolation and microscopic identification in relevant samples. Insufficiency of the conventional diagnostic tests may at least in part be due to sub-optimal sampling, processing of samples or inter- pretation of the results. 9,10 Although the various serological tests, that is, Aspergillus galactomannan Ag, Cryptococcus Ag, b-glucan and Candida mannan Ag and antimannan Ab have or will be dealt with in detail in separate papers, 11 the aim of this review is to provide an overview of the classical diagnostic options including imaging, microscopy, culture and susceptibility testing and their optimal use. A summary of these recommendations is provided in Tables 1 and 2. The recommendations were derived from published data generated in a number of different populations and were adapted to patients with haematological cancer when appropriate in the context of clinical relevance. However, the majority of these recommendations can be extrapolated to other patient categories as well. Direct examination Direct microscopic examination of samples is important for two reasons: 12 (i) it provides rapid information about the presence of fungi and other pathogens and may allow sufficient identification to guide management and (ii) it is more sensitive than culture for a number of samples. 13,14 Nevertheless, the result is only as good as the quality of the sample allows and thus obtaining optimal patient specimens is mandatory. Sample types Respiratory samples. The confirmation of many fungal infections is based on respiratory samples. Increasing the Received 10 February 2011; revised and accepted 12 October 2011; published online 9 January 2012 Correspondence: Dr MC Arendrup, Unit of Mycology and Parasitology, Statens Serum Institut, Ørestads Boulevard 5, DK-2300 Copenhagen, Denmark. E-mail: maca@ssi.dk Bone Marrow Transplantation (2012) 47, 1030–1045 & 2012 Macmillan Publishers Limited All rights reserved 0268-3369/12 www.nature.com/bmt