Immunocytochemical Reactivity Comparison between Formalin-Fixed and Liquid-Based Cytology-Fixed Specimens

Nanako Sakabe1, Sayumi Maruyama2, Chihiro Ito2

  • 1Pathophysiology Sciences, Department of Integrated Health Sciences, Nagoya University Graduate School of Medicine, Nagoya, Japan, nanako@met.nagoya-u.ac.jp.

Acta Cytologica
|October 13, 2022
PubMed

Insights

Liquid-based cytology (LBC) fixing solutions can impact immunocytochemistry (ICC) results. Careful selection of LBC methods and antibodies is crucial for accurate ICC detection in cell block specimens.

Area of Science:

  • Cytopathology
  • Immunohistochemistry
  • Biomedical research

Background:

  • Liquid-based cytology (LBC) offers advantages for preparing multiple specimens and performing immunocytochemistry (ICC).
  • However, LBC fixing solutions can alter antigenicity and affect ICC results.
  • This study investigates the impact of different LBC fixing solutions on ICC immunoreactivity.

Purpose of the Study:

  • To evaluate the effect of various LBC fixing solutions on the immunoreactivity of different antigens.
  • To compare ICC results from LBC-fixed samples with those from traditional 10% neutral buffered formalin (NBF)-fixed samples.

Main Methods:

  • Cell line samples were prepared using four LBC fixing solutions (PreservCyt®, CytoRich™ Red, CytoRich™ Blue, TACAS™ Ruby) and NBF fixation.
  • Specimens were post-fixed with NBF for ICC analysis.
  • Immunocytochemical staining was performed using 24 different antibodies, and the percentage of positive cells was quantified.

Main Results:

  • Immunoreactivity varied based on antigen type and fixing solution.
  • Nuclear antigens showed optimal results with NBF or TACAS™ Ruby, while cytoplasmic antigens performed well or better in LBC-fixed samples.
  • Significant reductions in positive cell percentages were observed for CEA, Ber-EP4, CD10, and D2-40 in specific LBC formulations compared to NBF.

Conclusions:

  • ICC on NBF-post-fixed LBC cell block specimens can yield comparable immunoreactivity to NBF-fixed samples.
  • The choice of LBC fixing solution influences antigen detection rates, depending on the antibody and antigen abundance.
  • Careful consideration of LBC methods and antibody selection is recommended for reliable ICC results.
Abstract