Maintenance of IVIGs increases its negative effect on expansion.

Purified human B lymphocytes were cultured as previously described with IL-4 and irradiated L4.5 cells. Cells were cultured with 10 mg/mL BSA and 5.3 mM glycine (♦) or with 10 mg/mL dialyzed IVIGs from day 0 to day 5 (▴) or from day 0 to day 19 (●). Total cell expansion on days 0, 5, 9, 14, and 19 has been evaluated in triplicate as indicated in Figure 1. Error bars, showing standard deviation for triplicates, might be smaller than symbols. Both IVIG preparations showed similar effect.