Anti-idiotypic activity against anti-myeloperoxidase antibodies in pooled human immunoglobulin

Clin Exp Immunol. 1994 Feb;95(2):257-62. doi: 10.1111/j.1365-2249.1994.tb06520.x.


We investigated the ability of six different pooled human immunoglobulin (PHIG) preparations to inhibit the binding of anti-myeloperoxidase (MPO) antibodies to MPO. All six PHIG preparations inhibited the binding of anti-MPO antibodies from six sera to MPO in a concentration-dependent manner in the concentration range 0.016-10 mg/ml. There was considerable variation in the ability of each PHIG preparation to inhibit the binding of anti-MPO antibody in a given serum. Further differences were seen in the ability of a given PHIG to inhibit anti-MPO binding in different sera. F(ab')2 fragments from two PHIG preparations also inhibited in a concentration-dependent manner anti-MPO binding to MPO in all six sera in the concentration range 0.002-2.65 mg/ml, with a maximum inhibition of 42%. Little inhibition was seen with F(ab')2 of normal human IgG from individual donors (1.8-12.2% at the maximum concentration of 2 mg/ml). F(ab')2 fragments from three anti-MPO containing sera and two affinity-purified anti-MPO antibodies were eluted by affinity chromatography from Sepharose-bound PHIG F(ab')2 and showed anti-MPO antibody activity. We have shown that PHIG and F(ab')2 fragments of PHIG inhibit anti-MPO binding to MPO, and further that F(ab')2 fragments of PHIG bind to F(ab')2 fragments of anti-MPO antibodies. These observations indicate binding between the variable regions of PHIG and the antigen binding site of anti-MPO antibodies, and are consistent with an anti-idiotypic reaction. The variability seen in the inhibitory effect of the different PHIG preparations in anti-MPO-positive sera implies differences in their anti-idiotype content, while the variability of the inhibitory effect of a particular PHIG preparation between different sera suggests heterogeneity in the idiotypic repertoire of anti-MPO antibodies. Such variations in the inhibitory effect of different PHIG preparations on antibody binding may be an important determinant of their therapeutic effect.

MeSH terms

  • Animals
  • Antibodies, Anti-Idiotypic / analysis*
  • Antibodies, Antineutrophil Cytoplasmic
  • Autoantibodies / immunology
  • Chromatography, Affinity
  • Humans
  • Immunoglobulin Fab Fragments / immunology
  • Immunoglobulin G / immunology
  • Immunoglobulins / immunology*
  • Mice
  • Peroxidase / immunology*


  • Antibodies, Anti-Idiotypic
  • Antibodies, Antineutrophil Cytoplasmic
  • Autoantibodies
  • Immunoglobulin Fab Fragments
  • Immunoglobulin G
  • Immunoglobulins
  • Peroxidase