Flow cytometric analysis of platelet surface glycoproteins in the diagnosis of thirty-two Turkish patients with Glanzmann thrombasthenia: a multicenter experience

Background/aim

Glanzmann thrombasthenia (GT) is a rare autosomal recessively inherited bleeding disorder characterized by the quantitative (type 1 and type 2) or qualitative (type 3) deficiency in platelet membrane glycoprotein (GP) IIb/IIIa (CD41a/CD61) fibrinogen receptors. In type 1, 2, and 3, CD41a/CD61 expression is 5%, 5%–20% and above 20%, respectively. In this study, diagnosis of GT was confirmed and subgroups were identified in 32 Turkish patients by flow cytometry analysis.

Materials and methods

CD41a/CD61 expression levels in platelet-rich plasma (PRP) obtained from peripheral venous EDTA blood samples were analyzed with a BD FACSCanto II flow cytometer (Becton Dickinson, Franklin Lakes, NJ, USA). GT subgroup analysis was performed by counting 50,000 events in the BD FACSDiva Software v6.1.3 program of the instrument.

Results

In the present study, in blood samples of 32 patients from 23 families with GT and 22 healthy controls, co-expression levels of CD41a and CD61 in PRP was analyzed. 12 out of 23 families were consistent with type 1 GT (52.2%), 4 were consistent with type 2 GT (17.4%), and 7 were consistent with type 3 GT (30.4%).

Conclusion

Especially due to consanguineous marriages, GT with various glycoprotein levels may be detected. As a result of the flow cytometry analysis of the present study with the highest GT patient population in Turkey, type 1 GT patients were the most common subgroup. In the determination of the GT subgroups; especially in the detection of type 3 GT, flow cytometry is the most sensitive glycoprotein analysis method. In addition to light transmission aggregometry, CD41a/CD61 study by flow cytometer confirms diagnosis when mutation analysis cannot be performed.