Molecular size of IgG in patients with focal glomerulosclerosis.

Nineteen patients with focal glomerulosclerosis and with anomalously high clearance of IgG into the urine have been investigated by G.200 column chromatography. The findings are compared with normal sera, with 14 patients with minimal change disease and with 12 patients with proliferative glomerulonephritis. No significant reduction in the molecular size of IgG was found as compared with normal sera and the other diseases in 18 of the patients. In patients with minimal change disease and focal glomerulosclerosis an increased proportion of the IgG eluted in the void volume