[Significance of MUC5B antibody in differential diagnosis between Aspergillus species and Mucorales of fungal sinusitis].
OBJECTIVE
To differentiate between Aspergillus species and Mucorales of fungal sinusitis by immunohistochemistry.


METHODS
Formalin-fixed paraffin-embedded tissue blocks of 66 cases of fungal sinusitis were retrieved from the archival files of Department of Pathology of Beijing Tongren Hospital during the period from 2001 to 2006. The samples included 29 cases of fungal balls, 12 cases of allergic fungal sinusitis, 24 cases of chronic invasive fungal sinusitis and 1 case of acute invasive fungal sinusitis. The types of fungi were 44 Aspergillus species (31 cases of A. fumigatus, 7 cases of A. flavus and 6 cases of A. terreus) and 22 Mucorales (14 cases of Mucor species and 8 cases of Rhizopus species). Immunohistochemistry was performed with MUC2, MUC5AC and MUC5B antibodies. The results were compared with histochemical study for periodic acid-Schiff (PAS) and Grocott methenamine silver (GMS) stains.


RESULTS
Immunohistochemical study for MUC5B showed that the positive rate of Aspergillus species was 90.9%, in contrast to 4.5% in Mucorales (P < 0.001). The expression of MUC2 and MUC5AC was completely negative, whereas PAS and GMS stains were positive in all cases.


CONCLUSIONS
MUC5B antibody appears to be a useful immunohistochemical marker for identifying fungal types in tissue sections, especially in distinguishing between Aspergillus species and Mucorales in fungal sinusitis.
Department of Pathology, Affiliated Beijing Tongren Hospital, Capital Medical University, Begiing, China.
Ying-shi
YS
Piao
Hong-gang
HG
Liu
Xian-jun
XJ
Liu
D000908:Antibodies, Fungal / Q000276:immunology; D000918:Antibody Specificity / Q000276:immunology; D001228:Aspergillosis / Q000175:diagnosis* / Q000276:immunology; D001231:Aspergillus flavus / Q000276:immunology*; D001232:Aspergillus fumigatus / Q000276:immunology*; D003937:Diagnosis, Differential; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods*; D055257:Mucin-5B / Q000235:genetics / Q000276:immunology*; D009089:Mucor / Q000276:immunology; D009181:Mycoses / Q000175:diagnosis / Q000276:immunology / Q000382:microbiology; D012852:Sinusitis / Q000175:diagnosis* / Q000382:microbiology
D000908:Antibodies, Fungal; C524578:MUC5B protein, human; D055257:Mucin-5B