Review
Laboratory diagnosis of invasive aspergillosis

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Summary

Invasive aspergillosis occurs in a wide range of clinical scenarios, is protean in its manifestations, and is still associated with an unacceptably high mortality rate. Early diagnosis is critical to a favourable outcome, but is difficult to achieve with current methods. Deep tissue diagnostic specimens are often difficult to obtain from critically ill patients. Newer antifungal agents exhibit differential mould activity, thus increasing the importance of establishing a specific diagnosis of invasive aspergillosis. For these reasons, a range of alternate diagnostic strategies have been investigated. Most investigative efforts have focused on molecular and serological diagnostic techniques. The detection of metabolites produced by Aspergillus spp and a range of aspergillus-specific antibodies represent additional, but relatively underused, diagnostic avenues. The detection of galactomannan has been incorporated into diagnostic criteria for invasive aspergillosis, reflecting an increased understanding of the performance, utility, and limitations of this technique. Measurement of (1,3)-β-D glucan in blood may be useful as a preliminary screening tool for invasive aspergillosis, despite the fact that this antigen can be detected in a number of other fungi. There have been extensive efforts directed toward the detection of Aspergillus spp DNA, but a lack of technical standardisation and relatively poor understanding of DNA release and kinetics continues to hamper the broad applicability of this technique. This review considers the application, utility, and limitations of the currently available and investigational diagnostic modalities for invasive aspergillosis.

Introduction

Aspergillus spp are ubiquitous opportunistic moulds that cause both allergic and invasive syndromes. The genus comprises approximately 180 species, of which 33 have been associated with human disease. Most infections are caused by Aspergillus fumigatus, Aspergillus flavus, Aspergillus terreus, and Aspergillus niger;1 less commonly, Aspergillus nidulans can be implicated as the causative pathogen, especially in the setting of chronic granulomatous disease.2

An accurate diagnosis of invasive aspergillosis is important for clinical reasons; an earlier diagnosis is associated with improved patient survival3 and tests with a high negative predictive value may allow expensive and potentially toxic antifungal drugs to be withheld. New drugs—eg, voriconazole—exhibit differential mould activity; the ability to specifically exploit their anti-aspergillus properties requires a rapid and accurate laboratory diagnosis. The epidemiology of invasive aspergillosis is changing; invasive disease is increasingly observed in the non-neutropenic phase of haematopoietic stem cell transplantation4, 5, 6 and in non-classic settings such as critically ill patients in intensive care units.7 Aspergillus spp other than A fumigatus—some of which demonstrate inherent resistance to antifungal drugs—are increasingly recognised.8, 9, 10 An international collaborative effort recently produced standardised definitions for invasive fungal infections.11 Thus, a review of the diagnostic modalities and their use in establishing a diagnosis of invasive aspergillosis is timely.

Section snippets

Direct techniques

The advantages of direct techniques over culture include superior sensitivity and a relatively rapid turn around time. The principal disadvantage is the inability to definitively distinguish other filamentous fungi (eg, Penicillium spp and Scedosporium spp) or implicate Aspergillus spp as the causative pathogen in circumstances in which there are atypical or non-specific morphological features. This disadvantage may compromise diagnostic accuracy and hence estimates of therapeutic efficacy if

Laboratory isolates

Given the distinct differences in disease manifestations, prognosis, and antifungal susceptibility between different fungal genera and species, a rapid diagnosis will assume increasing importance. The inherent problems with identification using culture methods have been outlined. An increasing number of studies have examined the use of PCR to enable the accurate and rapid detection of laboratory isolates (table 3). The rapid identification of laboratory isolates using microarray technology with

Future challenges

Invasive aspergillosis continues to pose many challenges. From a diagnostic point of view, improving the test accuracy remains a priority for patient care, therapeutic research, and future diagnostic research. The question, of course, is the manner in which these improvements can be achieved. The progressive refinement of existing techniques and development of new diagnostic technologies is clearly a priority. Substantial work remains in areas related to cost-effectiveness and whether patients

Search strategy and selection criteria

PubMed was searched for English-language literature using the following terms: “Aspergillus”, “aspergillosis”, “diagnosis”, “fungus”, “fungal”, “culture”, “histology”, “galactomannan”, “glucan”, “serology”, “antibody”, “PCR”, “molecular”, “metabolite”, “mannitol”, and “gliotoxin”. Further relevant references, not identified by this strategy, were retrieved from the primary publications.

References (133)

  • S Bretagne

    Molecular diagnostics in clinical parasitology and mycology: limits of the current polymerase chain reaction (PCR) assays and interest of the real-time PCR assays

    Clin Microbiol Infect

    (2003)
  • JR Perfect et al.

    The impact of culture isolation of Aspergillus species: a hospital-based survey of aspergillosis

    Clin Infect Dis

    (2001)
  • BH Segal et al.

    Aspergillus nidulans infection in chronic granulomatous disease

    Medicine (Baltimore)

    (1998)
  • M von Eiff et al.

    Pulmonary aspergillosis: early diagnosis improves survival

    Respiration

    (1995)
  • A Wald et al.

    Epidemiology of Aspergillus infections in a large cohort of patients undergoing bone marrow transplantation

    J Infect Dis

    (1997)
  • WB Grow et al.

    Late onset of invasive Aspergillus infection in bone marrow transplant patients at a university hospital

    Bone Marrow Transplant

    (2002)
  • GJ Alangaden et al.

    Aspergillosis: the most common community-acquired pneumonia with gram-negative bacilli as copathogens in stem cell transplant recipients with graft-versus-host disease

    Clin Infect Dis

    (2002)
  • W Meersseman et al.

    Invasive aspergillosis in critically ill patients without malignancy

    Am J Respir Crit Care Med

    (2004)
  • RY Hachem et al.

    Aspergillus terreus: an emerging amphotericin B-resistant opportunistic mold in patients with hematologic malignancies

    Cancer

    (2004)
  • WJ Steinbach et al.

    Infections due to Aspergillus terreus: a multicenter retrospective analysis of 83 cases

    Clin Infect Dis

    (2004)
  • TJ Walsh et al.

    Experimental pulmonary aspergillosis due to Aspergillus terreus: pathogenesis and treatment of an emerging fungal pathogen resistant to amphotericin B

    J Infect Dis

    (2003)
  • S Ascioglu et al.

    Defining opportunistic invasive fungal infections in immunocompromised patients with cancer and hematopoietic stem cell transplants: an international consensus

    Clin Infect Dis

    (2002)
  • WG Merz et al.

    Algorithims for detection and identification of fungi

  • RG Grocott

    A stain for fungi in tissue sections and smears using Gomori's methenamine-silver nitrate technic

    Am J Clin Pathol

    (1955)
  • R Ruchel et al.

    Versatile fluorescent staining of fungi in clinical specimens by using the optical brightener Blankophor

    J Clin Microbiol

    (1999)
  • J Chander et al.

    Evaluation of Calcofluor staining in the diagnosis of fungal corneal ulcer

    Mycoses

    (1993)
  • JK Choi et al.

    Immunohistochemical detection of Aspergillus species in pediatric tissue samples

    Am J Clin Pathol

    (2004)
  • L Kaufman et al.

    Immunohistologic identification of Aspergillus spp. and other hyaline fungi by using polyclonal fluorescent antibodies

    J Clin Microbiol

    (1997)
  • PE Verweij et al.

    Immunoperoxidase staining for identification of Aspergillus species in routinely processed tissue sections

    J Clin Pathol

    (1996)
  • RL Zimmerman et al.

    Ultra fast identification of Aspergillus species in pulmonary cytology specimens by in situ hybridization

    Int J Mol Med

    (2000)
  • RT Hayden et al.

    In situ hybridization for the differentiation of Aspergillus, Fusarium, and Pseudallescheria species in tissue section

    Diagn Mol Pathol

    (2003)
  • DP Kontoyiannis et al.

    Aspergillus nidulans is frequently resistant to amphotericin B

    Mycoses

    (2002)
  • JJ Tarrand et al.

    Diagnosis of invasive septate mold infections

    Am J Clin Pathol

    (2003)
  • DA Sutton

    Specimen collection, transport, and processing: mycology

  • GS de Hoog et al.

    Atlas of clinical fungi

    (2000)
  • MA Klich

    Identification of common Aspergillus species

    (2002)
  • ME Callister et al.

    A fatal case of disseminated aspergillosis caused by a non-sporulating strain of Aspergillus fumigatus

    J Clin Pathol

    (2004)
  • JP Latge et al.

    Chemical and immunological characterization of the extracellular galactomannan of Aspergillus fumigatus

    Infect Immun

    (1994)
  • KA Marr et al.

    Detection of galactomannan antigenemia by enzyme immunoassay for the diagnosis of invasive aspergillosis: variables that affect performance

    J Infect Dis

    (2004)
  • P Francis et al.

    Efficacy of unilamellar liposomal amphotericin B in treatment of pulmonary aspergillosis in persistently granulocytopenic rabbits: the potential role of bronchoalveolar D-mannitol and serum galactomannan as markers of infection

    J Infect Dis

    (1994)
  • F Boutboul et al.

    Invasive aspergillosis in allogeneic stem cell transplant recipients: increasing antigenemia is associated with progressive disease

    Clin Infect Dis

    (2002)
  • MJ Becker et al.

    Galactomannan detection in computerized tomography-based broncho-alveolar lavage fluid and serum in haematological patients at risk for invasive pulmonary aspergillosis

    Br J Haematol

    (2003)
  • RR Klont et al.

    Utility of Aspergillus antigen detection in specimens other than serum specimens

    Clin Infect Dis

    (2004)
  • D Stynen et al.

    A new sensitive sandwich enzyme-linked immunosorbent assay to detect galactofuran in patients with invasive aspergillosis

    J Clin Microbiol

    (1995)
  • PE Verweij et al.

    Sandwich enzyme-linked immunosorbent assay compared with Pastorex latex agglutination test for diagnosing invasive aspergillosis in immunocompromised patients

    J Clin Microbiol

    (1995)
  • F Dalle et al.

    False-positive results caused by cotton swabs in commercial Aspergillus antigen latex agglutination test

    Eur J Clin Microbiol Infect Dis

    (2002)
  • CM Swanink et al.

    Specificity of a sandwich enzyme-linked immunosorbent assay for detecting Aspergillus galactomannan

    J Clin Microbiol

    (1997)
  • R Kappe et al.

    New cause for false-positive results with the Pastorex Aspergillus antigen latex agglutination test

    J Clin Microbiol

    (1993)
  • JE Bennett et al.

    Forum report: issues in the evaluation of diagnostic tests, use of historical controls, and merits of the current multicenter collaborative groups

    Clin Infect Dis

    (2003)
  • R Herbrecht et al.

    Aspergillus galactomannan detection in the diagnosis of invasive aspergillosis in cancer patients

    J Clin Oncol

    (2002)
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