CytoLyt~R Fixation and Decalcification Pretreatments Alter Antigenicity in Normal Tissues Compared With Standard Formalin Fixation

摘要

Immunohistochemistry is used on cell blocks constructed from cytopathology samples fixed in methanol-based fixatives, such as CytoLyt~R (Cytyc Corp), and on surgical pathology tissues exposed to decalcifying agents, often without technical validation. We evaluated a panel of commonly utilized antibodies in normal tissues exposed to differing preanalytic conditions as follows: CytoLyt~R fixation, formalin fixation followed by exposure to decalcifying agents (Leica Decalcifier 1-10% formic acid or Leica Decalcifier 11-5% hydrochloric acid), or standard formalin fixation. Altered expression was observed with several antibodies compared with standard formalin fixation. Specifically, there was absent or near absent expression of thyroid transcription factor 1 (TTF-1), D2-40, and CD20 in CytoLyt-fixed tissues, whereas reduced expression was observed for p63, estrogen receptor, S100 protein, CD3, calre-tinin, chromogranin, and synaptophysin.