IVIGs induce high IgG reactivities against dsDNA, F(ab′)2 and tetanus toxin.
(A) Supernatants from B lymphocytes cultured for 14 days with 4 mM glycine and 10 mg/mL BSA (■) or with 10 mg/mL dialyzed IVIGs (▪) and commercial IVIGs (░) were adjusted to 100 ng/mL IgG. Reactivities for human IgG F(ab′)2 and Fc fragments, and tetanus toxin (TT) were determined by ELISA as described in “Materials and methods.” Background reactivities of ELISA are shown for each Ag (▤) as are reactivities of each sample in the absence of coated Ag (none). (B) Dilutions of IVIG-induced IgG (triangle) and commercial IVIGs (diamond) were used in titration ELISA to quantify IgG reactivities for dsDNA (filled symbols) and human IgG F(ab′)2 fragments (open symbols) as described in “Materials and methods.” Both antigens were adsorbed at 10 μg/mL. Background reactivities in these ELISAs for dsDNA and F(ab′)2 fragments were 0.05 OD and 0.06 OD, respectively, at 490 nm. Error bars, showing standard deviation for triplicates, can be smaller than symbols.
