Expression of platelet membrane glycoprotein Ib/IX/V complex, a receptor of thrombin, in patients with hemorrhagic thrombopathy.

To investigate the role of platelet membrane glycoprotein (GP) Ib/IX/V complex and its subunit GP Ibalpha in patients with hemorrhagic thrombopathy (HT), the expressions of GP Ib/IX/V complex and GP Ibalpha, defined as mean fluorescence intensity (MFI), were assessed by flow cytometry. The maximum aggregation of platelet was determined by turbidity method. These indicators were compared among 68 HT patients with the presenting complaint of hemorrhage, 33 well-controlled HT patients and 32 normal healthy subjects. The results showed that the MFI of GP Ib/IX/V complex and GP Ibalpha was markedly lower in HT patients with current hemorrhage than that in the healthy subjects, with difference being statistically significant (P<0.05). There was no significant difference in the expressions of GP Ib/IX/V complex and GP Ibalpha between well-controlled HT patients and normal healthy subjects (P>0.05). It was concluded that the expression of GP Ib/IX/V complex, the receptor of thrombin and von Willebrand factor, was down-regulated in HT patients with current hemorrhage, which might result in the dysfunction of platelet aggregation and recurrence of HT.