Fig. 4.

Proliferation of human mesangial cells stimulated with fractions of serum from three patients with IgAN. Native-serum samples from three IgAN patients (filled circles in panels a, b, and c) were fractionated on a calibrated Superose 6 column; the fractions were filter-sterilized and added to serum-starved human mesangial cells. Cellular proliferation was measured after 20-h incubation. IgA-depleted serum sample from one IgAN patient (empty circles in panel a) served as a negative control.