Cytopathic Effects of Antigens in Patients with IgA Nephropathy

The cytopathic effects of extracts of pharyngeal cells from patients with IgA nephropathy on fibroblasts were determined. Autoradiographical analysis of antigens in the fibroblasts was also described. Freeze and thawed extracts of pharyngeal cells obtained from patients with IgA nephropathy, other glomerular diseases and healthy adults were cultured with fibroblasts such as Vero or Hel cells at 37°C for 1 or 2 weeks. The cytopathic effects of fibroblasts were examined with a light microscope. In addition, the eluate obtained from renal tissues of IgA nephropathy was labeled with iodine-125 by the chloramine-T method. These cultured fibroblasts were incubated with iodine-125-labeled eluate from the same or other patients with IgA nephropathy. The degree of cytopathic effects of extracts of pharyngeal cells from patients with IgA nephropathy on Vero or Hel cells was significantly increased compared with that from patients with other glomerular diseases or healthy adults without glomerular diseases. The cytopathic effects of such fibroblasts were not inhibited by filtration of extracts of pharyngeal cells obtained from patients with IgA nephropathy. It was shown that the antibodies eluted from renal tissues of patients with IgA nephropathy specifically bound with the nuclear regions of such fibroblasts. It was suggested that some antigenic substances might exist in the epithelial cells of the upper respiratory tracts of some patients with IgA nephropathy, and that such antigens were able to be transferred to cultured fibroblasts.