Imunorreatividade em material histol��gico arquivado durante um, quatro e sete anos

Quando aplicada no ��mbito da Anatomia Patol��gica, a imuno-histoqu��mica tem constitu��do um poderoso meio de identifica����o/caracteriza����o de v��rias estruturas histol��gicas, permitindo delinear progn��stico e terap��utica para v��rias patologias. Tendo em conta que as amostras histol��gicas analisadas podem ser conservadas ao longo de v��rios anos, interessa avaliar a manuten����o da antigenicidade ao longo do tempo, de forma a garantir a qualidade final da t��cnica quando aplicada em material de arquivo. Assim, o principal objetivo deste trabalho foi comparar a imunorreatividade do material histol��gico arquivado durante um, quatro e sete anos. Foi utilizado material histol��gico de pr��stata, pulm��o e mama, no qual se procedeu �� imunomarca����o de citoqueratinas (Clones AE1/AE3), CD34 e prote��na p63, por m��todo de mult��mero/HRP no sistema Ventana BenchMark Ultra��. Foi realizado um ensaio com recupera����o antig��nica por alta temperatura (RAAT) e outro sem esta etapa. As imunomarca����es (n=162) foram classificadas por tr��s avaliadores independentes num escore quantitativo final (escala 0-100). O par m��dia/desvio-padr��o do escore final para os casos com sete anos foi de 69,06/19,05, para os casos com quatro anos foi de 66,47/20,73 e para os casos com um ano foi de 69,08/19,35, n��o se tendo encontrado diferen��as estatisticamente significativas. Os casos sem RAAT obtiveram um par m��dia/desvio-padr��o de 54,90/17,00, enquanto os casos com RAAT obtiveram 81,50/11,60, o que revelou diferen��as estatisticamente significativas (p=0,000). Para os casos em estudo conclui-se que o fator ���tempo de arquivo��� n��o est�� associado a altera����es da imunorreatividade. A import��ncia da RAAT na obten����o de imunomarca����o de qualidade sai fortemente real��ada. ABSTRACT - When applied within the framework of Pathology, immunohistochemistry has been a powerful means of identification/characterization of various histological structures, allowing to outline prognosis and therapy for various diseases. Given that the analyzed histological samples can be preserved for several years, it is interesting to assess the retention of antigenicity over time in order to ensure the quality of the final technique, when applied to stored material. Thus, the main objective of this study was to compare the immunoreactivity of the histological material archived for one, four and seven years. It was used histological material from prostate, lung and breast, in which it was performed the immunostaining of cytokeratins (clones AE1/AE3), CD34 and p63 protein by the method of multimer/HRP system on a Ventana BenchMark Ultra��. It was conducted a test with heat induced epitope retrieval (HIER) and another one without this step. The stained slides (n=162) were classified by three independent assessors using a quantitative score (scale 0-100). The pair mean/standard deviation of the score for cases with seven years was 69,06/19,05, for cases with four years was 66,47/20,73 and for cases with one year was 69,08/19,35, which did not revealed any statistically significant differences. The cases without HIER had a couple mean/standard deviation of 54.90/17.00 while the cases with HIER obtained 81.50/11.60, which revealed statistically significant differences (p=0.000). For this case study it was concluded that the factor archive period is not associated with changes in immunoreactivity. The importance of HIER in obtaining high quality immunostaining comes out strongly highlighted.