Table 3.

Adhesion of Platelets to Collagen Type I in the Absence (None) and in the Presence of Affinity-Purified IgG From Normal Human Serum, Anti-Sita, or Murine MoAb Gi9 Specific for GPIa/IIa

Platelets Phenotypes IgGCollagen Type I (OD410)
50 μg/mL1 μg/mL
Sita (−)  None  0.79 ± 0.11 0.68 ± 0.11  
 Normal serum  1.15 ± 0.20 0.86 ± 0.20  
 Anti-Sita 1.25 ± 0.15 1.01 ± 0.08  
 MoAb Gi9  0.29 ± 0.04 0.20 ± 0.03  
Sita (+)  None 0.85 ± 0.25  0.62 ± 0.18  
 Normal serum 1.20 ± 0.15  0.94 ± 0.13  
 Anti-Sita 1.32 ± 0.12  1.01 ± 0.08  
 MoAb Gi9 0.28 ± 0.12  0.21 ± 0.05 
Platelets Phenotypes IgGCollagen Type I (OD410)
50 μg/mL1 μg/mL
Sita (−)  None  0.79 ± 0.11 0.68 ± 0.11  
 Normal serum  1.15 ± 0.20 0.86 ± 0.20  
 Anti-Sita 1.25 ± 0.15 1.01 ± 0.08  
 MoAb Gi9  0.29 ± 0.04 0.20 ± 0.03  
Sita (+)  None 0.85 ± 0.25  0.62 ± 0.18  
 Normal serum 1.20 ± 0.15  0.94 ± 0.13  
 Anti-Sita 1.32 ± 0.12  1.01 ± 0.08  
 MoAb Gi9 0.28 ± 0.12  0.21 ± 0.05 

Biotinylated platelets from Sita (−) individuals or Sita (+) individuals (B.III.2 and 3 in Fig 2) were allowed to adhere to microtiter wells coated with either BSA (10 mg/mL) or collagen type I (50 and 1 μg/mL). Results are represented as the means of optical density (OD410) ± SD for triplicate samples. The OD410 of platelet adhesion to wells coated with BSA was less than 0.16 ± 0.07. The number of donors tested was 2.