THE V KAPPA-IIIB LIGHT CHAIN SUB-SUBGROUP .2. ISOTYPE EXPRESSION IN ACQUIRED HYPOGAMMAGLOBULINEMIA AND AS A FUNCTION OF AGE

Google Scholar
  • 1 February 1986
    • journal article
    • research article
    • Vol. 57  (2) , 325-328
Abstract
The V.kappa. IIIb sub-subgroup of the human immunoglobulin V.kappa.III light chain subgroup has at least two unique properties. First, some IgM monoclonal autoantibodies, in particular cryoprecipitable anti-IgG (Kunkel et al., 1974; Ledford et al., 1983), anti-low density lipoprotein (Ledford et al., 1983) and certain cold agglutinin (Feizi et al., 1976) antibodies predominantly contain V.kappa.IIIb light chains. Second, in normal adult human serum, V.kappa.IIIb comprises approximately 25% of the IgM but less than 0.4% of the IgG or IgA kappa-chain pools (Moynihan, Looney and Abraham, 1985). Studies have suggested an altered regulation of IgM, IgG, and IgA-V.kappa.IIIb in some patients with acquired hypogammaglobulinaemia, a heterogeneous group of immunodeficiencies with low serum levels of Ig. An increase in the serum levels of V.kappa.IIIb light chains has been noted in some of these patients (Solomon and Mclaughli, 1969) which is apparently due to elevated levels of light chains of the V.kappa.IIIb sub-subgroup (Greenstein and Abraham, 1984). However, the isotype association of V.kappa.IIIb in these patients has not been determined. In order the clarify whether the noted increase in V.kappa.IIIb levels is due to its selective expression with IgM or to an abnormality of immunoregulation, the heavy chain isotypes associated with V.kappa.IIIb light chains have been determined in a previously studied group of adults with acquired hypogammaglobulinaemia (Greenstein and Ambraham, 1984). Further, the isotype distribution of V.kappa.IIIb light chains in another group of functional, albeit transient, hypogammaglobulinaemics (i.e. normal neonates) has been studied by measuring IgM-V.kappa.IIIb levels in cord blood, and compared to the VkIIIb serum levels found in aged adults (mean age 75 years).