Detection of polymeric IgA in sera from patients with IgA nephropathy determined by thin-layer gel filtration.

Polymeric IgA in sera was determined by thin-layer gel filtration in patients with IgA nephropathy, other glomerular diseases, IgA myeloma and healthy adults to determine whether serum IgA is composed of a monomeric and/or larger polymers in these patients. The levels of IgA in sera were also quantitated by laser nephelometer in these patients. Eleven patients with IgA nephropathy (Berger's disease), six patients with other glomerular diseases, three patients with IgA myeloma and four healthy adults were examined. It was shown that the polymerized IgA in sera from patients with IgA nephropathy was significantly higher than that in sera from patients with other glomerular diseases and healthy adults. Levels of IgA in sera from patients with IgA nephropathy are significantly higher than that in sera from patients with other glomerular diseases and healthy adults. These findings suggest that an increase in serum IgA from patients with IgA nephropathy may be mainly due to an increase in polymers rather than the monomer of IgA.