This goal of this project is to qualify the first system of reference standards and measurement traceability in immunohistochemistry (IHC) testing as a Medical Device Development Tool (MDDT), topic 442. In all other types of laboratory testing, such as clinical chemistry, these metrologic tools are a standard of laboratory practice. FDA requires test manufacturers to identify methods of assay calibration. IHC is the exception. Instead, there are poorly standardized, improvised systems of calibration based on immunoreactivity with various tissues. This deficiency has led to IHC error rates that are ten times those in other laboratory testing disciplines. Boston Cell Standards developed tools to solve this problem and validated them in 3 large clinical trials. Our proposed MDDT, a system of IHC assay calibration traceable to NIST SRM 1934, is applicable to any manufacturers IHC assay. This Phase I proposal addresses 4 improvements that were identified during clinical testing: (1) commutability of reference materials, (2) calculating the difference between ERF and molar concentrations, (3) improving traceability to NIST SRM 1934, and (4) developing a better method for calibrator value assignment. These small steps will make a large impact in the field of surgical pathology and IHC.
