Fig. 6.

Amelioration of thrombocytopenia with intravenous immunoglobulin (IVIG) preparations. IVIG was administered intraperitoneally to groups of five mice. After 24 h, 2 µg of anti-CD41 monoclonal antibody (mAb) was administered intraperitoneally. Blood samples were obtained 2 h before and 3, 6 and 24 h after administration of anti-CD41 mAb. Platelets were counted by an electronic cell counter. The means ± standard deviation (s.d.) are indicated by symbols with bars. (a) Thrombocytopenia amelioration with GG, polymer + dimer fraction and monomer fraction separated from gammaglobulin (GG). Polymer + dimer fraction (open squares), monomer fraction (open diamonds) or the parental GG (open triangles) was administered intraperitoneally at a dose of 0·2 g/kg. Phosphate-buffered saline (PBS) was used as the control (closed circles). (b) Amelioration of thrombocytopenia with GG at the dose of 2 g/kg (open squares), 1 g/kg (open triangles) or 0·5 g/kg (open diamonds). The control was PBS (closed circles). (c) Amelioration of thrombocytopenia with S-sulfonated gammaglobulin (SGG). The doses are the same as those in (b). In an additional experiment, 6 h before anti-CD41 mAb, 2 g/kg of SGG was administered intraperitoneally and the platelets were counted (closed squares). (d) Amelioration of thrombocytopenia with S-alkylated gammaglobulin (AGG). The doses are the same as those in (b). An asterisk and double asterisk indicate significant differences (P < 0·01 and P < 0·001, respectively) between the platelet counts with S-alkylated gammaglobulin (AGG) and GG. The platelet counts of the five mice in each group were expressed as the mean ± s.d.