Validation of Linear Range HER2/Estrogen Receptor/Progesterone Receptor IHControls for Daily Quality Assurance

Area of Science:

• Biomedical diagnostics
• Immunohistochemistry
• Quality control

Background:

• Immunohistochemistry (IHC) is crucial for cancer diagnostics, relying on accurate controls.
• Traditional tissue controls can have variability and limitations.
• A new FDA-cleared control, IHControls, utilizes peptide epitopes on microspheres.

Purpose of the Study:

• To evaluate the performance of IHControls for HER2, estrogen receptor (ER), and progesterone receptor (PR).
• To compare IHControls against conventional tissue controls in clinical IHC laboratories.
• To assess the sensitivity, reproducibility, and specificity of IHControls.

Main Methods:

• Side-by-side comparison of IHControls and tissue/cell line controls across 5 clinical labs.
• Simulated IHC assay failure experiments using primary antibody dilution.
• Evaluation of lot-to-lot manufacturing reproducibility and specificity against irrelevant stains.

Main Results:

• Achieved 99.6% concordance between IHControls and tissue controls across 766 evaluations.
• Both control types demonstrated similar sensitivity in detecting IHC assay errors.
• IHControls showed <10% variability in manufacturing reproducibility and no cross-reactivity.

Conclusions:

• IHControls are the first FDA-cleared IHC controls.
• They offer sensitive and accurate detection of IHC assay problems.
• Performance is comparable to traditional tissue controls.