Analysis of Platelet Membrane Glycoprotein Iib-IIIa Complex in Whole Blood of Glanzmann's Thrombasthenia by Flow Cytometry

ABSTRACT

Glanzmann's thrombasthenia is a rare autosomal recessive hemorrhagic disorder characterized by prolonged bleeding time, ad deficient or absent clot retraction in the presence of normal platelet count. The major underlying abnormality in this disease is grossly defective first-phase aggregation of platelet, which are unresponsive to ADP or other platelet agonists such as epinephrine, collagen, thrombin in any concentration. This disability is caused by a decrease or absence of the platelet membrans glycoprotein IIb-IIIa complex, a member of the integrin family of adhesive receptors involved in cell-cell and cell-matrix fibronectin, and vitronectin On the development of surface labeling technique, a variety of biochemical techniques such as radioimmunoassay, crossed immunoelectrophoresis and SDS-PAGE have been used to study the structure and the function of platelet membrane glycoproteins, and to detect the platelet functional defect. But all of these techniques demand a relatively large amount of homogeneous paletelet population that requires manipulation through isolation and washing procedures before analysis. In order to eliminaste such an intricate procedure, we have applied method for analyzing platelet surface components in whole blood using monoclonal antibody and flow cytometry to recognize the absence of severe reduction of platelet membrane glycoprotien llb-llla complex. Platelet analysis by flow cytometry is a successful alternative rapid diagnostic technique for Glanzmann's thrombasthenia patients as well as well as for carriers of this disease. Fow cytometry technique provides a sensitive tool for investigating platelet functional defects caused by altered expression or deficiency of platelet surface proteins.