title: Evaluation of HER2 Protein Expression Using 2 New Monoclonal Antibodies.
abstract: This study describes the performance of 2 new mouse anti-HER2 monoclonal antibodies (Abs), clones 33F and 410G, in evaluating HER2 overexpression in a series of 123 invasive breast carcinoma cases. In-house immunohistochemistry (IHC) was performed and the results were compared with those for the SP3 and A0485 anti-HER2 Abs. Chromogenic in situ hybridization was used to detect ERBB2 amplification and its concordance with IHC was analyzed. Comparison of IHC results for 33F with SP3 and A0485 yielded concordance rates (K) of 0.81 and 0.75, respectively; the same concordance rates were found when comparing results for 410G with SP3 and A0485. Compared with SP3 and A0485, 33F and 410G specificities were 98.6% and 98.6%, and 100% and 100%, respectively, whereas the sensitivities were 80% and 74.1%, and 78% and 72.2%, respectively. The K values between 33F and 410G HER2+ expression and chromogenic in situ hybridization-positive amplification were 1 and 0.96, respectively. These concordance rates were reproduced in another production batch (K=0.96 and K=0.96). Together, these results show that the tested monoclonal Abs would be well suited for detecting HER2 protein overexpression by IHC.
authors.affiliation: *Postgraduation Program in Pathology, Pathology Research Laboratory, Universidade Federal de Ciências da Saúde de Porto Alegre (UFCSPA), Porto Alegre †Postgraduation Program in Biotechnology, Technology Development Center, Universidade Federal de Pelotas (UFPEL), Pelotas, Rio Grande do Sul, Brazil.
authors.forename: Pedro B
authors.initials: PB
authors.lastname: Aleixo
authors.forename: Rosalva T
authors.initials: RT
authors.lastname: Meurer
authors.forename: Flávia A
authors.initials: FA
authors.lastname: Vasconcellos
authors.forename: Fabricio R
authors.initials: FR
authors.lastname: Conceição
authors.forename: José A G
authors.initials: JA
authors.lastname: Aleixo
authors.forename: Antonio A
authors.initials: AA
authors.lastname: Hartmann
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D000911:Antibodies, Monoclonal / Q000737:chemistry* / Q000302:isolation & purification; D014408:Biomarkers, Tumor / Q000235:genetics*; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology; D018270:Carcinoma, Ductal, Breast / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology; D005260:Female; D015870:Gene Expression; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D051379:Mice; D008875:Middle Aged; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000235:genetics*; D012680:Sensitivity and Specificity
chemical_list: D000911:Antibodies, Monoclonal; D014408:Biomarkers, Tumor; D018719:Erb-b2 Receptor Tyrosine Kinases; C508053:ERBB2 protein, human