THE ELIMINATION OF CIRCULATING COMPLEXES CONTAINING POLYMERIC IGA BY EXCRETION IN THE BILE

  • 1 January 1981
    • journal article
    • research article
    • Vol. 42  (1) , 83-89
Abstract
Radiolabeled human dimeric IgA injected i.v. into rats behaved like oligomeric rat IgA in that 40% of the injected dose was recovered in the bile within 6 h. Monomeric IgA was not transported into bile. In addition, dimeric IgA was able to carry with it macromolecular material in the form of a complex that also included rat secretory component. This was demonstrated in rats which had received an i.v. injection of specifically purified radiolabeled rabbit antibody to a human IgA myeloma idiotype: when a later injection of unlabeled IgA dimer with the corresponding idiotype was given, up to 18% of the rabbit antibody was carried through into the bile; this did not occur when the monomeric form of the same IgA was injected. This mechanism for clearing complexes containing polymeric IgA is mediated by hepatocytes and distinct from the phagocyte-mediated mechanisms which clear conventional complexes.