Human immunoglobulin (Ig) E synthesis is regulated by T-cell-derived binding factors which include potentiating factors and suppressor factors (IgE-SFs) and B-cell-derived factors. Seventeen cases of primary glomerulonephritis (GN) with nephrotic syndrome and high serum IgE were studied for their serum IgE-SFs. These include 8 cases of minimal-change disease (MCD), 3 cases of IgM nephropathy, 4 cases of focal segmental glomerulosclerosis, and 2 cases of IgA nephropathy, aged between 20 and 60 years (mean: 37.2). A significantly lower activity of these factors was noted in the patient group as shown by a lower overall inhibition rate on in vitro IgE synthesis (median: 22.9 vs. 53.2%, p < 0.05). Some of them even exhibited an enhancing activity in their serum as shown by a negative inhibition rate. These findings suggest that there is a T cell disorder in some of the primary GNs with high serum IgE, especially in MCD, which causes an abnormal regulation of IgE synthesis.