title: Diagnosis of filamentous fungi on tissue sections by immunohistochemistry using anti-aspergillus antibody.
abstract: Identification based on histology alone has limitations as Aspergillus species share morphology with other filamentous fungi. Differentiation of Aspergillus species from hyalohyphomycetes and dematiaceous fungi is important as the antifungal susceptibility varies among different species and genera. Given these problems, ancillary techniques are needed to increase specificity. Our aim was to study the utility of immunohistochemistry (IHC) with anti-Aspergillus antibody in the identification of Aspergillus species and to differentiate them from other filamentous fungi. Fifty formalin fixed, paraffin embedded tissue sections including 47 from cases of culture proven filamentous fungi, 3 from colonies of cultures of hyalohyphomycetes, and 11 smears from cultures were subjected to IHC studies using polyclonal rabbit anti-Aspergillus antibody (Abcam, UK) after antigen retrieval. The IHC on tissue sections was positive in 88% cases involving culture proven Aspergillus species. There was no cross reactivity with Mucorales species, Candida species, dematiaceous fungi and hyalohyphomycetes. Hence immunohistochemistry can be used as an ancillary technique for the diagnosis of Aspergillus species.
authors.affiliation: Department of Pathology, Nizam's Institute of Medical Sciences, Andhra Pradesh, India challa_sundaram@yahoo.com.
authors.forename: Sundaram
authors.initials: S
authors.lastname: Challa
authors.affiliation: Department of Pathology, Nizam's Institute of Medical Sciences, Andhra Pradesh, India.
authors.forename: Shantveer G
authors.initials: SG
authors.lastname: Uppin
authors.affiliation: Department of Pathology, Nizam's Institute of Medical Sciences, Andhra Pradesh, India.
authors.forename: Megha S
authors.initials: MS
authors.lastname: Uppin
authors.affiliation: Department of Microbiology, Nizam's Institute of Medical Sciences, Andhra Pradesh, India.
authors.forename: Umabala
authors.initials: U
authors.lastname: Pamidimukkala
authors.affiliation: Department of Microbiology, Nizam's Institute of Medical Sciences, Andhra Pradesh, India.
authors.forename: Lakshmi
authors.initials: L
authors.lastname: Vemu
mesh_terms: D000908:Antibodies, Fungal / Q000276:immunology*; D001228:Aspergillosis / Q000175:diagnosis*; D001230:Aspergillus / Q000276:immunology*; D003429:Cross Reactions; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods*; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D006113:United Kingdom
chemical_list: D000908:Antibodies, Fungal
keywords: Aspergillus; IHC; ancillary techniques; filamentous fungi; morphology