Effect of liquid-based cytology fixing solution on immunocytochemistry: Efficacy of antigen retrieval in cytologic

Nanako Sakabe1, Sayumi Maruyama1, Chihiro Ito1

  • 1Pathophysiology Sciences, Department of Integrated Health Sciences, Nagoya University Graduate School of Medicine, Nagoya, Japan.

PubMed

Insights

Immunocytochemistry (ICC) on liquid-based cytology (LBC) specimens shows improved results with antigen retrieval (AR). However, optimal staining for ICC depends on the specific antigen, cell type, and LBC fixing solution used.

Area of Science:

  • Cytopathology
  • Immunohistochemistry
  • Diagnostic Pathology

Background:

  • Immunocytochemistry (ICC) enhances diagnostic accuracy in cytology.
  • Liquid-based cytology (LBC) is a common method for specimen preparation.
  • Appropriate fixation is crucial for successful ICC on LBC specimens.

Purpose of the Study:

  • To investigate the impact of LBC fixing solutions on ICC.
  • To evaluate the efficacy of antigen retrieval (AR) in LBC specimens for ICC.

Main Methods:

  • Utilized five types of LBC-fixed samples (SurePath™) with cell lines.
  • Performed ICC using 13 antibodies.
  • Analyzed results by quantifying positive cells in stained specimens.

Main Results:

  • Heat-induced AR (HIAR) significantly improved ICC reactivity for nuclear antigens.
  • Reactivity varied based on LBC fixing solutions (CytoRich™ Blue, CytoRich™ Red, TACAS™ Ruby) and specific antigens (e.g., Ki-67, estrogen receptor, p63, cytokeratin 5/6).
  • Cytoplasmic and cell membrane antigens showed reduced reactivity without HIAR and with certain LBC fixatives.

Conclusions:

  • ICC on LBC specimens is a valuable diagnostic tool.
  • Staining conditions, including the choice of LBC fixing solution and the need for AR, must be optimized for each antigen.
  • The interplay between antigen, cell type, and fixative impacts ICC immunoreactivity.
Abstract