IVIGs reduce B-lymphocyte expansion in CD40-CD154 system.

Purified human B lymphocytes were cultured with irradiated L4.5 cells in complete medium containing IL-4 without (diamond, plain line) or with (dashed lines) 10 mg/mL IVIGs (triangle) or 15 mg/mL IVIGs (circle) for 14 days. Cell expansion was based on seeding cell number and viable cell count evaluated in triplicate at the indicated day by trypan blue exclusion. (A) Culture controls were done with stabilizers sucrose (S) and human serum albumin (HSA) (open symbols, filled line), and stabilizers plus bovine serum albumin (BSA) (filled symbols, plain line) in concentrations corresponding to 10 mg/mL IVIGs (triangle) and 15 mg/mL IVIGs (circle) as indicated. (B) Culture controls were done as described above with 5.3 mM and 8 mM glycine (G) and BSA (filled symbols, filled plain line), and with BSA only (open symbols, plain line) in both cases BSA was in concentrations corresponding to 10 mg/mL dialyzed IVIGs (triangle) and 15 mg/mL dialyzed IVIGs (circle) as indicated. A and B were done with the B lymphocytes from 2 donors. Error bars, showing standard deviation for triplicates, might be smaller than symbols. These results are representative of 3 independent experiments.