Purpose of review: Immunohistochemistry is an integral technique for tissue-based diagnostics and biomarker detection with broad worldwide adoption. Advances in core chemistries, antibody design, and automation have ushered unprecedented sensitivity, specificity, and reproducibility in immunohistochemistry assays. As a result, clinical immunohistochemistry assays that utilize dual-color approaches and mutation-specific antibodies provide novel tools in clinical diagnostics that until recently were in the realm of investigational research. This review provides an overview of innovations in clinical immunohistochemistry assays with emphasis on those used for patients with hematopoietic neoplasms.
Recent findings: Advances in clinical-grade immunohistochemistry techniques have allowed labs to develop and validate multiplex assays that improve diagnostic utility-such as CD5/PAX5 and TCF4/CD123 dual-color stains-and have the potential to enhance the specificity of biomarker detection. In addition, the increased availability of immunohistochemistry assays that detect mutant proteins (e.g., BRAF V600E and IDH1 R132H) provides a helpful replacement and/or adjunct for molecular testing. These techniques are highly reproducible, entail reasonable technical and interpretation complexity, and are relatively cost-effective, making them valuable novel tools in modern cancer care. Multiplex and mutation-specific immunohistochemistry assays represent important innovations that provide improved utility in the context of personalized medicine and targeted therapy.
Keywords: BRAF V600E; CD123; Dual immunohistochemistry; IDH1; LEF1; Multiplex immunohistochemistry; Mutation-specific antibody; PAX5; TCF4.