Affiliations: Laboratório de Imunopatologia Keizo Asami
(LIKA), Universidade Federal de Pernambuco (UFPE), Recife, Brazil | Departamento de Bioquímica – Centro de
Ciências Biológicas, Universidade Federal de Pernambuco (UFPE),
Recife, Brazil
Note: [] orresponding author: Eduardo Beltrão, Laboratório
de Imunopatologia Keizo Asami-LIKA, Universidade Federal de Pernambuco –
UFPE, Av. Prof. Morais Rêgo s/n, Campus Universitário, 50670-910
PE, Brazil. Tel.: +55 81 2101 2504; Fax: +55 81 2126 8485; E-mail:
ebeltrao@hotmail.com
Abstract: Her-2 status evaluation in breast cancer has prognostic and
treatment response value but its interobserver variation among pathologists is
a problem since it is not quantitatively assayed. This study presents an
immunohistochemiluminescence method to quantify Her-2 in breast cancer.
Anti-Her-2 antibody was conjugated to acridinium ester (AE) and used to
evaluate/quantify Her-2 status in breast Invasive Ductal Carcinoma (IDC, n=50)
comparing with traditional immunohistochemistry. Anti-HER-2-AE results were
expressed in Relative Lights Units (RLU) and showed to be able to distinguish
and quantify the differences between the three groups of Her-2 status. 3+ Her-2
status presented the highest RLU (246,982 × 10^{3}
± 2.061 × 10^{3}) compared to 2+ (76,146
× 10^{3} ± 0.290 ×
10^{3}), negative (27,415 × 10^{3}
± 1.445 × 10^{3}) and normal tissues (27,064
× 10^{3} ± 2.060). Status differences were
significant between 3+ and 2+ (p=0.0025); 2+ and negative (p=0.0003), and +3
and +1 (p=0.0001) beside this, normal breast control RLU was 27,064 ×
10^{3} ± 2,060 × 10^{3},
similar to negative cases. Results showed that anti-HER-2-AE conjugate was
effective in breast tumors Her-2 status evaluation, allowing its quantitative
establishment to consequently decrease the subjectivity in prognostic and
predictive information intrinsic to this test.
