Estrogen Receptors in Immunohistochemically Stained Slides: Comparing Subjective and Computerized Evaluation Methods

Abstract

SUMMARY:Immunohistochemistry is a specific and sensitive staining method for detection of several proteins. One important function of this method is to help us on the diagnosis of the presence of specific receptors as the estrogen receptors. The aim of this study was to compare two different methods to evaluate immunohistochemical staining intensity to detect the presence of ER in the nasal mucosa tissue: one using a digital system and the other through conventional direct microscopy observation. Sixty two stained samples were observed and analyzed under optic microscopy by three specialized professionals, who have graded intensity from: absent, mild, moderate and intense staining. Afterwards, an objective measurement was obtained by a relative optical density (ROD) reading, through the MCID 7.0 system of densitometric digital analysis (Inter Focus Imaging LTDA, Linton, England). Subjective and objective classifications were compared under statistical analysis (Kolmogorov-Smirnov and Spearman Correlation Test, p<0.05). We found a positive correlation between the subjective findings of observers and digital analysis in all the categories of beta receptor. For the alpha receptor, there was a correlation only in extreme categories. The subjective evaluations by observers and digital method by measuring the relative optical density show statistically significant correlations in quantifying the estrogen receptors by immunohistochemistry staining. This indicates that both methods show accuracy for the proposed study.