Purpose: To evaluate the efficacy of different diagnostic methods for invasive aspergillosis (IA) in patients with haematologic neoplasms.
Patients: Eight patients were evaluated for this study (5 non-Hodgkin's lymphomas, 2 acute leukaemias, and 1 chronic myelogenous leukaemia in blastic crisis). Depending on the clinical characteristics of each case, one or more diagnostic procedures were used: (a) microscopic observation of fresh samples from sputum, urine sediment, or fine-needle aspirate; (b) culture in Sabouraud agar, glucose-gentamicin medium of the pathologic products; (c) serologic techniques for detecting anti-Aspergillus spp antibodies and circulating antigen; (d) histologic examination of biopsy or necropsy specimens.
Results: The combination of microbiological methods (i.e., direct observation, culture, serology) provided the IA diagnosis in the 8 cases, this being confirmed by histologic observation in 5 instances (3 of them in necropsy studies). The observation of fresh samples allowed us to identify hyphae on different locations, although the culture of such material not always was positive. Seroconversion for Aspergillus spp was seen in 4 patients, whereas the antigen detection was negative in the 5 patients in whom this was attempted.
Conclusions: (1) These findings suggest that different microbiological techniques must be combined for IA diagnosis when suspected in a severely compromised patient. (2) Direct microscopic observation may be of help, as it is a simple method allowing faster results than culture. (3) Serologic techniques, especially circulating antigen detection, are not fully developed.