title: Immunohistochemistry quantification by a digital computer-assisted method compared to semiquantitative analysis.
abstract: OBJECTIVE
  To compare immunostaining quantification obtained by a digital computer-assisted method with the well-established semiquantitative analysis.
  
  
  METHODS
  Cytoplasmic staining of galectin-3 was obtained by standard immunohistochemical reactions in 25 cases of well-differentiated thyroid carcinoma. The expression index that associates the conventional area fraction of labeled cells with the immunostaining intensity score based on visual qualitative observation was used as the semiquantitative analysis. A digital computer-assisted method is described based on the use of an image processing program (ImageLab). Three parameters were obtained: (1) percentage of labeled cells; (2) digital immunostaining intensity, and (3) digital expression index. The proposed method allows numerical analysis of the immunostaining intensity.
  
  
  RESULTS
  There was a strong correlation between the immunostaining intensity obtained by the two methods (Pearson correlation coefficient, r = 0.71, P = 0.0001). The same was observed between expression indexes (Pearson correlation coefficient, r = 0.66, P = 0.0001).
  
  
  CONCLUSIONS
  Results obtained with our proposed digital computer-assisted method for immunoexpression analysis were concordant with the semiquantitative analysis. In addition, digital values can also resolve disagreement among different observers about the quality of staining intensity because the digital method does not classify the results into groups, but rather provides a numerical value for each individual case; thus, it increases the diagnostic and, more importantly, the prognostic sensitivity of the immunohistochemical analysis.
authors.affiliation: Biochemistry Department, Molecular Biology Laboratory, Faculty of Medicine, ABC Foundation, São Paulo, SP, Brazil. lmatos@amcham.com.br
authors.forename: Leandro Luongo de
authors.initials: LL
authors.lastname: Matos
authors.forename: Elaine
authors.initials: E
authors.lastname: Stabenow
authors.forename: Marcos Roberto
authors.initials: MR
authors.lastname: Tavares
authors.forename: Alberto Rosseti
authors.initials: AR
authors.lastname: Ferraz
authors.forename: Vera Luiza
authors.initials: VL
authors.lastname: Capelozzi
authors.forename: Maria Aparecida da Silva
authors.initials: MA
authors.lastname: Pinhal
mesh_terms: D000704:Analysis of Variance; D014408:Biomarkers, Tumor / Q000032:analysis*; D002277:Carcinoma / Q000175:diagnosis / Q000648:ultrastructure; D002454:Cell Differentiation; D037502:Galectin 3 / Q000032:analysis; D006801:Humans; D019044:Image Cytometry / Q000379:methods*; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D007150:Immunohistochemistry / Q000379:methods*; D013194:Staining and Labeling / Q000706:statistics & numerical data*; D013964:Thyroid Neoplasms / Q000175:diagnosis / Q000648:ultrastructure
chemical_list: D014408:Biomarkers, Tumor; D037502:Galectin 3