Immunoglobulin kappa light chain (IGK) (IGK)

The Immunoglobulin kappa light chain is a fundamental component of the humoral immune system, serving as one of the two types of light chains that pair with heavy chains to form functional antibodies. Produced by plasma cells, these chains are essential for antigen recognition and the diversity of the B-cell receptor repertoire [1]. Under normal physiological conditions, a small amount of free light chain is secreted into the blood and cleared by the kidneys [2]. In pathological states such as multiple myeloma or AL amyloidosis, a clonal population of plasma cells produces excessive amounts of monoclonal kappa light chains [3]. These proteins can become proteotoxic or aggregate into insoluble amyloid fibrils that deposit in vital organs, most notably the kidneys and heart, causing organ failure [4]. Modern therapeutic approaches involve both the suppression of the underlying plasma cell clone and the development of targeted antibodies, such as CAEL-101, which specifically bind to misfolded light chains to promote their clearance [5]. Monitoring the levels of these chains via the serum free light chain assay is critical for diagnosing and managing plasma cell disorders [6].

Other names

Kappa light chainIg kappaIGKCIGKVImmunoglobulin kappa constantImmunoglobulin kappa variable

Binding to misfolded or aggregated light chains to facilitate their clearance by phagocytic cells and prevent further organ deposition.