Immunoglobulin kappa constant region (IGKC) (IGKC)

The Immunoglobulin kappa constant region (IGKC) is the invariant portion of the kappa light chain in antibodies and B-cell receptors (UniProt: P01834). In humans, B-cells express either a kappa or a lambda light chain, a phenomenon known as allelic exclusion (PubMed: 26239086). This makes IGKC an attractive therapeutic target for B-cell malignancies, such as multiple myeloma and non-Hodgkin lymphoma, where the tumor is often restricted to a single light chain type (PubMed: 31515258). By targeting IGKC, therapies like CAR-T cells can selectively eliminate the malignant kappa-positive B-cell population while sparing lambda-positive B-cells, thereby preserving a degree of humoral immunity (ClinicalTrials.gov: NCT04440631). This approach aims to reduce the profound immunosuppression typically seen with pan-B-cell targets like CD19 or CD20. Additionally, IGKC is a critical biomarker in the diagnosis and monitoring of plasma cell dyscrasias through the measurement of free light chain ratios (PubMed: 19300231).

Other names

IGKCIg kappa chain C regionImmunoglobulin kappa constantHCAK1Km antigen

Targeted depletion of B-lineage cells expressing the kappa light chain, preserving lambda-expressing B-cells to maintain partial humoral immunity (PubMed: 31515258).