Modulation of platelet surface adhesion receptors during cardiopulmonary bypass.
Alterations in platelet receptors critical to adhesion may play a role in the pathogenesis of the qualitative platelet defect associated with cardiopulmonary bypass. Using flow cytometry, we measured changes in the following platelet surface adhesive proteins: the von Willebrand factor receptor, glycoprotein Ib; the fibrinogen receptor, glycoprotein IIb/IIIa; the thrombospondin receptor, glycoprotein IV; the adhesive glycoprotein granule membrane protein 140, whose expression also reflects platelet activation and alpha-granule release; and, as a control, the nonreceptor protein HLA, A,B,C. Glycoprotein Ib decreased during cardiopulmonary bypass (P less than 0.05) and reached a nadir at 72% (P less than 0.05) of its baseline value at 2-4 h after bypass. This decrease correlated (r = 0.76) with the magnitude of platelet activation (alpha-granule release) in any given patient, but even platelets that were not activated demonstrated a decrease in glycoprotein Ib expression. Glycoprotein IIb/IIIa also decreased in both the activated (47% of baseline, P less than 0.01) and unactivated (63% of baseline, P less than 0.01) subsets of platelets at the end of cardiopulmonary bypass. Glycoprotein IV and HLA A,B,C did not decrease, but instead increased 2-4 h after cardiopulmonary bypass (P less than 0.05). We conclude that cardiopulmonary bypass produces selective decreases in surface glycoproteins Ib and IIb/IIIa as well as in platelet activation; that these two alterations are temporally but not necessarily mechanistically linked; and that these changes have the potential to adversely affect platelet function.
Rinder
C S
CS
Department of Anesthesiology, Yale University School of Medicine, New Haven, Connecticut 06510.
Mathew
J P
JP
Rinder
H M
HM
Bonan
J
J
Ault
K A
KA
Smith
B R
BR
D018955:CD36 Antigens; D002315:Cardiopulmonary Bypass; D005434:Flow Cytometry; D006801:Humans; D019007:P-Selectin; D015539:Platelet Activation / Q000502:physiology; D010973:Platelet Adhesiveness / Q000502:physiology*; D010980:Platelet Membrane Glycoproteins / Q000502:physiology*; D011956:Receptors, Cell Surface / Q000502:physiology*; D016024:Receptors, Cytoadhesin / Q000502:physiology
D018955:CD36 Antigens; D019007:P-Selectin; D010980:Platelet Membrane Glycoproteins; D011956:Receptors, Cell Surface; D016024:Receptors, Cytoadhesin; C028254:von Willebrand factor receptor