Flow cytometry, Western blotting analysis, and enzyme immunoassays were performed as described in Materials and Methods. In the flow cytometry analysis, GPIIb, GPIIIa, and GPIb were determined by using the M3, P95.2, and anti-GPIb/IX MoAbs, respectively. The values are means ± SD of the mean fluorescence channel of the number of observations indicated in parentheses. In Western blotting and enzyme immunoassay analysis, the GPIIb and GPIIIa content in the detergent solubilized particulate fraction of sonicated platelets was detected using the M3 and P95.2 MoAbs, respectively. Western blotting data were quantitated by computerized image analysis. The mean values ± SD in control platelets were as follows: for GPIIb, 58 ± 7 (n = 6); for GPIIIa, 40 ± 7 (n = 6), expressed in arbitrary units per microgram of protein. The values for the proband and her relatives are the mean ± SE of six different analyses of the same platelet preparation run in duplicates and are expressed as the percentage of the control values. The mean ± SD values for the enzyme immunoassay of GPIIb/IIIa in control platelet were as follows: for GPIIb, 3.7 ± 0.7 (wt/wt; n = 18); for GPIIIa, 2.4 ± 0.7 (wt/wt; n = 17), expressed as the percentage of the total protein content.

Abbreviation: ND, not detectable.