[Invasive pulmonary aspergillosis in immunocompromized children: diagnosis and classification].

Invasive aspergillosis is an opportunistic infection, with frequent lung involvement. High-risk children are allogenic bone marrow recipients, and those with hematological malignancies, aplastic anemia or chronic granulomatous disease. Profound and prolonged neutropenia, and corticosteroid therapy are the most important predisposing factors. Building and demolition works represent the major environmental risk factor. The diagnosis of invasive aspergillosis remains difficult to establish. Clinical manifestations are non-specific. Early thoracic computed tomographic scan shows halo sign in most cases. Subsequently appears the air crescent sign. Galactomannan research by sandwich ELISA can be useful in serum and in bronchoalveolar lavage fluid. Aspergillus DNA detection by PCR is still not standardized. Culture of the organism allows species identification. Aspergillus hyphae can be found at cytological examination, but a biopsy specimen is usually required to affirm tissue damage. A new classification of invasive fungal infections in immunocompromised patients was recently proposed by experts from the European Organization for Research and Treatment of Cancer and from the Mycoses Study Group of the National Institute of Allergy and Infectious Diseases. On the basis of host linked criteria, microbiological, clinical and radiological features, invasive aspergillosis is classified as proven, probable or possible. These definitions should not be used to guide clinical practice in therapy, but they will improve the quality of epidemiological data, and help the comparison of clinical trial results.