Effect of blocking antibodies, fibrinogen, and shear rate on erythrocyte adhesion to platelets.

(A) Comparison of percent adhesion (γ_w = 50 s⁻¹, 5 minutes) with the control demonstrated reduction in erythrocyte adhesion to collagen-adherent platelets in the presence of anti-CD36, anti-GPIb, or soluble fibrinogen. RBC adhesion on collagen-adherent platelets was 4-fold greater than on fibrinogen-adherent platelets. The average platelet density (number of platelets on surface/unit area) for both collagen-adherent platelets and fibrinogen-adherent platelets was 11.6 (± 1.5) × 10³ platelets/mm². (B) Erythrocyte adhesion at 5 minutes to collagen-adherent platelets was found to be inversely correlated to shear rate (n = 3). Data are expressed as means ± SD of n replicated experiments.