Getting controls under control: the time is now for immunohistochemistry

Area of Science:

• Biomedical diagnostics
• Laboratory medicine
• Histopathology

Background:

• Diagnostic immunohistochemistry (dIHC) has historically been viewed as an art, lacking rigorous scientific test performance characterization.
• Key test performance characteristics for dIHC have not been clearly defined, hindering its recognition as a standardized laboratory test.
• The absence of standardized controls and reference standards has contributed to variability and a lack of reproducibility in dIHC.

Purpose of the Study:

• To highlight the critical role of standardization in diagnostic immunohistochemistry (dIHC).
• To discuss the necessity of defining and evaluating relevant test performance characteristics for dIHC.
• To emphasize the importance of standardized external controls and reference standards for dIHC.

Main Methods:

• Literature review and conceptual discussion on the standardization of immunohistochemistry.
• Analysis of the impact of undefined test performance characteristics on dIHC.
• Exploration of the role of external controls and reference standards in IHC standardization.

Main Results:

• Diagnostic IHC has lacked clear definitions for test performance characteristics.
• There is a significant need for standardized controls and reference standards in dIHC.
• Standardization efforts are crucial for establishing dIHC as a reliable laboratory test.

Conclusions:

• Standardizing external controls is essential for defining dIHC test performance characteristics.
• Standardized controls and reference standards are fundamental for the overall standardization of IHC.
• Implementing standardization will enhance the reliability and reproducibility of diagnostic IHC.