Invasive Myceliophthora thermophila infection mimicking invasive aspergillosis in a neutropenic patient: a new cause of cross-reactivity with the Aspergillus galactomannan serum antigen assay
Trichosporon species), dimorphic fungi and to a lesser extent moulds [3 -8] According to a recent report, crossreaction could also occur in cases of zygomycosis but this warrants further investigations as the results are not supported by previous fi ndings for zygomycetes in the literature [8,9] We described the case of a neutropenic patient presenting with an acute myeloid leukaemia (AML) who was thought to have developed probable IA due to positive results in the GM assay in accord with the
... RTC/MSG criteria. However, the etiologic agent was subsequently identifi ed as the rare thermophilic mould Myceliophthora thermophila which was found experimentally to cross react in the Aspergillus galactomannan assay. The patient was successfully treated with voriconazole. Case report A 52-year-old man was admitted to the haematology department for treatment of AML FAB2, with an unfavourable prognosis due to multilineage dysplasia, hyperleukocytosis and abnomal karyotype (t(1;11) and 17p deletion). The Myceliophthora thermophila is a thermophilic mould widely found in the environment but rarely responsible for human infections. We describe a case of invasive Myceliophthora thermophila infection mimicking invasive aspergillosis in a neutropenic patient with haematological malignancy. Cross-reactivity with Aspergillus galactomannan assay (GM) was demonstrated by repeated positive results and confi rmed by cross-reaction between the fungal isolate and the GM assay. The patient was successfully treated with voriconazole. Potential GM cross-reactivity must be considered in future studies including patients categorized as having probable invasive aspergillosis using the GM as the only mycological criterion.