Validazione della reattività immunoistochimica di un pannello anticorpale in diverse specie ittiche mediante l’impiego di “Tissue Array”

SUMMARY - Immunohistochemistry (IHC) is a valuable technique for both diagnosis and research of infectious and neoplastic diseases in a variety of animals. When dealing with fish tissues these challenges are far more arduous, because of compelling differences between mammal and fish tissues, since cross-reactivity has not been extensively tested in these animals. The aim of this research was to test a standardized panel of commercial antibodies used in our histopathology laboratory, to verify their cross-reactivity, if any, when compared with mammal tissues. Twelve commercial species were sampled. Various tissues were formalin-fixed and paraffinembedded. A tissue array was constructed for each fish; replicate sections were cut at 3 μm and underwent to a IHC protocol. The antibodies employed were directed against epithelial (AE1/AE3 cytokeratins, CK5/6, CK14, CK19, E-cadherin), mesenchymal (vimentin, desmin, α-actin, factor VIII-RA), haemopoietic (CD3, CD18 canine and CD18 feline, CD45-RA, CD79α, CD117, MAC 387), endocrine (chromogranin A, synaptophysin), cell cycle antigens (Ki67 and hTERT) and S100 protein. Seven out of 21 antibodies tested (CKAE1/AE3, CK5/6, Ecadherin, vimentin, CD117, synaptophysin, hTERT) were immunoreactive, and immunopositivity had the expected location. Our findings allow, when cross-reactivity is validated, to extend IHC application on fish species, in order to identify tissue and cell components.