No abstract

Background-Experiments under controlled flow conditions indicate that the binding of von Willebrand factor (vWF) to platelet glycoprotein (GP) Ib␣ and integrin ␣ IIb ␤ 3 (GP IIb/IIIa complex) is crucial for aggregation at elevated shear rates. We have tested how the plasma of patients with acute myocardial infarction affects this process. Methods and Results-Citrated plasma was obtained from 18 patients with acute myocardial infarction within 6 hours from the onset of symptoms and from 26 control subjects with chest pain syndrome without evidence of ischemia. Aggregation of normal platelets at high shear rates was significantly greater in the presence of patient than control plasma and was inhibited by both anti-GP Ib␣ and anti-␣ IIb ␤ 3 monoclonal antibodies. The observed values (meanϮSD) were 47.6Ϯ17.8% versus 30.1Ϯ9.9% at 10 800 s Ϫ1 (PϽ0.01) and 32.9Ϯ14.1% versus 17.5Ϯ9.5% at 7200 s Ϫ1 (PϽ0.01), respectively, and were positively correlated with plasma vWF antigen levels and ristocetin cofactor activities. In contrast, at the lower shear rate of 1200 s Ϫ1 , aggregation was similar in the presence of control or patient plasma and was not inhibited by the anti-GP Ib␣ antibody. Both vWF antigen and platelet aggregation decreased 2 weeks after the onset of myocardial infarction. Conclusions-Shear-induced platelet aggregation is enhanced in plasma in the presence of acute myocardial infarction, apparently as a result of increased vWF concentration. This may contribute to the onset of acute coronary artery thrombosis and early reocclusion after reperfusion treatment. (Circulation. 1999;99:608-613.)

IgG4-related hypophysitis may have different clinical characteristics between genders. This survey may lack some information because the Japanese abstracts did not contain certain details.