Evaluation of platelet glycoprotein Ib by fluorescence flow cytometry
B Adelman, AD Michelson, RI Handin and KA Ault
Platelet glycoprotein Ib (GpIb), a receptor for von Willebrand's factor
(vWF), was studied by way of fluorescence flow cytometry. Using a sandwich
staining technique, GpIb was identified by a monoclonal antibody (6D1)
directed against an epitope close to the vWF binding site. Platelets from
normal individuals were symmetrically distributed with respect to GpIb
content. Treatment of washed platelets with plasmin resulted in progressive
loss of GpIb as measured by fluorescence flow cytometry and by loss of
agglutination response when combined with ristocetin in the presence of
vWF. In mixing experiments with GpIb-deficient and normal platelets, it was
possible to detect a subpopulation of deficient cells comprising 2% of the
total population. Streptokinase treatment of platelet-rich plasma caused
loss of the agglutination response to ristocetin and the emergence of a
population of GpIb-deficient platelets. Fluorescence flow cytometry appears
to be an important new technique by which to study platelet surface
receptors.
Volume 66,
Issue 2,
pp. 423-427,
08/01/1985
Copyright © 1985 by The American Society of Hematology
