Flow cytometric analysis of the binding of an anti–HPA-4a antibody to the Duv^a+ allelic form of the GP IIb-IIIa complex.

Cos cells expressing the Duv^a− (white bar) or the Duv^a+(gray bar) forms of the GP IIb-IIIa or nontransfected (black bar) were incubated with an AB serum as control and a serum containing an anti–HPA-4a antibody. Human bound IgGs were detected by flow cytometry as described in the legend to Figure 3. The anti–HPA-4a antibody reacted with both types of cells independently of the allelic forms of the GP IIb-IIIa. The serum AB did not show any significant reactivity whatever the cell type tested. Results correspond to a mean of 3 experiments ± SD.