Administration of monoclonal antibodies with specificity for erythrocytes can inhibit immune thrombocytopenia in SCID mice.

The indicated dose of monoclonal antibody or 50 mg IVIG (■) was administered to SCID mice followed by anti-α_IIb antibody at 24 hours. After a further 24 hours, platelet counts were performed. (A) Anti–TER-119; (B) anti-CD24 (IgG_2b); (C) anti-CD24 (IgG_2c). Normal, the dotted line indicates the mean platelet count of unmanipulated mice; ITP, the hatched rectangle indicates the range of the mean platelet count (± 1 SEM) of mice treated with antiplatelet antibody only. The x-axis denotes the treatments given to mice (50 mg IVIG or the indicated dose of monoclonal antibody); the y-axis denotes the platelet count; n = 9 for each data point. *P < .05; ***P < .001 as compared with ITP mice. Error bars indicate SEM.