Fig. 3.

The effects of IVIg on the secretion of primary and secondary allo-human leucocyte antigen (HLA) class II immunoglobulin (Ig)G antibodies by activated B lymphocytes obtained from the alloimmunized woman. GamaSTAN S/D IVIg was used at 1:100 dilution; 1·5 mg protein/ml. At the time when IVIg was added, cytokine combo and anti-CD40 antibody were not added. In all panels, the mean fluorescent intensity (MFI) of alloantibody secretion is compared between medium control and treatment with IVIg. (a) Effects of IVIg on the secretion of the primary alloantibody directed against DRB1*0101. (b–f) Effects of IVIg on the secretion of the secondary alloantibodies (b). DRB1*0102; (c) DRB1*0404; (d) DRB1*0405; (e) DRB1*1402; (f) DRB1*0401). IVIg inhibited the secretion of the primary alloantibody (P² < 0·04) but no such inhibition is evident with other alloantibodies. Indeed, IVIg increased the secretion of several alloantibodies (DRB1*0405, DRB1*1402, DRB1*0401) (see arrows) at significant levels.