Kappa (κ) light chain
Measurement of the various amounts of the different types of light chains aids in the diagnosis of multiple myeloma, lymphocytic neoplasms, Waldenström's macroglobulinemia, and connective tissue diseases such as rheumatoid arthritis or systemic lupus erythematosus.
Every plasma cell clone normally produces a uniform immunoglobulin molecule of the kappa or lambda light chain type. The kappa:lambda ratio in serum is normally around 2:1.
Pathological increases of a cell clone lead to elevated formation of monoclonal immunoglobulins or immunoglobulin fragments (free light chains), which bring about a change in the kappa:lambda ratio. A kappa:lambda ratio outside the normal range is indicative of monoclonal gammopathy.
This test encompasses both bound and free immunoglobulins of the light chain type.
It is known that the so-called paraproteins secreted in monoclonal gammopathies (monoclonal immunoglobulinemia) may differ from the respective immunoglobulins of polyclonal origin in amino acid composition and size. This may impair the binding to antibody and consequently cause antigen excess below the limits determined with immunoglobulins of polyclonal origin. Antigen excess may be detected after appropriate dilution of such samples.
Furthermore, the occurrence of two monoclonal gammopathies producing differing light chain types could theoretically lead to kappa:lambda ratios in the normal range
SI units Conversion Calculator. Convert Kappa (κ) light chain level to g/L, mg/dL, mg/100mL, mg%, mg/mL . Clinical laboratory units online conversion from conventional or traditional units to Si units. Table of conversion factors for Kappa (κ) light chain unit conversion to g/L, mg/dL, mg/100mL, mg%, mg/mL .