Enhanced platelet adhesion to collagen in scleroderma. Effect of scleroderma plasma and scleroderma platelets

The effect of plasma on platelet adhesion to collagen coated microtiter wells was investigated in 22 patients with scleroderma and 26 control subjects. In the control subjects, platelet adhesion was 38 +/- 13% (mean +/- SD) of adhesion with buffer alone; in scleroderma patients adhesion was 64 +/- 20% (p less than 0.001). No correlation was seen between the effect of plasma on platelet adhesion to collagen and the plasma levels of either FVIII/von Willebrand factor antigen or fibronectin in either scleroderma or control subjects. Furthermore, scleroderma platelets demonstrated enhanced adhesion compared to control platelets when tested in the presence of either control or scleroderma plasma.