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Comparison of three staining methods to identify eosinophils in formalin‐fixed canine skin
Author(s) -
Gomes Paulo,
Torres Sheila M. F.,
Plager Douglas A.,
Jessen Carl R.,
Lee James J.
Publication year - 2013
Publication title -
veterinary dermatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.744
H-Index - 60
eISSN - 1365-3164
pISSN - 0959-4493
DOI - 10.1111/vde.12029
Subject(s) - staining , eosinophil , stain , eosin , pathology , haematoxylin , h&e stain , medicine , immunology , asthma
Background Studies comparing the ability of staining methods to detect eosinophils in formalin‐fixed canine skin are lacking. Hypothesis/Objectives The aim of this study was to compare the effectiveness of eosinophil peroxidase monoclonal antibody ( EPX mAb), L una and haematoxylin and eosin ( H&E ) to detect eosinophils in fixed canine skin by assessing the following parameters: (i) specificity of eosinophil staining; (ii) extracellular eosinophil granule staining; (iii) tissue background staining; (iv) contrast between eosinophil and surrounding tissue staining; and (v) differences in the number of eosinophils detected by each stain. Methods Three serial sections of formalin‐fixed, paraffin‐embedded tissues of predominantly eosinophilic skin diseases ( n = 8), noneosinophilic skin diseases ( n = 7) and normal canine skin ( n = 1) were stained with the three stains. Each parameter was independently assessed and scored by two investigators. Results Luna and EPX m A b were specific in detecting eosinophils. The EPX m A b was significantly more effective than Luna ( P < 0.001) and H&E ( P < 0.001) in its ability to detect extracellular eosinophil granules (i.e. to detect intact and released eosinophil granules). The EPX m A b showed significantly less background staining compared with Luna ( P = 0.0005). Moreover, significantly more stain contrast was noted with EPX m A b compared with L una ( P = 0.003) and H&E ( P < 0.001). There was no significant difference between the mean eosinophil counts among the three stains. Conclusion and clinical importance The three stains were shown to be useful to detect and quantify eosinophils in fixed canine skin. The EPX m A b‐based immunohistochemical stain proved to be a novel tool to detect eosinophils in canine skin.