Reproducibility studies for experimental epitope detection in macrophages (EDIM)

J Immunol Methods. 2014 May:407:40-7. doi: 10.1016/j.jim.2014.03.018. Epub 2014 Mar 28.


Introduction: We have recently described epitope detection in macrophages (EDIM) by flow cytometry. This is a promising tool for the diagnosis and follow-up of malignancies. However, biological and technical validation is warranted before clinical applicability can be explored.

Methods: The pre-analytic and analytic phases were investigated. Five different aspects were assessed: blood sample stability, intra-individual variability in healthy persons, intra-assay variation, inter-assay variation and assay transferability. The post-analytic phase was already partly standardized and described in an earlier study.

Results: The outcomes in the pre-analytic phase showed that samples are stable for 24h after venipuncture. Biological variation over time was similar to that of serum tumor marker assays; each patient has a baseline value. Intra-assay variation showed good reproducibility, while inter-assay variation showed reproducibility similar to that of to established serum tumor marker assays. Furthermore, the assay showed excellent transferability between analyzers.

Conclusion: Under optimal analytic conditions the EDIM method is technically stable, reproducible and transferable. Biological variation over time needs further assessment in future work.

Keywords: Analytic; Colorectal Cancer; Epitope detection in macrophages; Flowcytometry; Pre-analytic; Reproducibility.

Publication types

  • Validation Study

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Biomarkers, Tumor / analysis*
  • Cell Separation
  • Colorectal Neoplasms / diagnosis*
  • Colorectal Neoplasms / immunology
  • Epinephrine / analysis*
  • Female
  • Flow Cytometry
  • Humans
  • Macrophages / immunology*
  • Male
  • Middle Aged
  • Reproducibility of Results
  • Sensitivity and Specificity


  • Biomarkers, Tumor
  • Epinephrine