A whole blood flow cytometric determination of platelet activation by unfractionated and low molecular weight heparin in vitro.
The influence of unfractionated (Heparin-Natrium) and low-molecular heparin (Fragmin(R)) on platelet activation in whole blood was investigated by FACS analysis in vitro using antibodies against glycoprotein (gp) IIb/IIIa (CD 41), GMP 140 (CD 62P), gp 53 (CD 63) and fibrinogen. Samples were also labeled with anti-gp Ib (CD 42b). Neither unfractionated heparin (UFH) nor low molecular weight heparin (LMWH) led to significant (i.e., p<0.05) changes in fluorescence intensities of platelets labeled with anti-gp IIb/IIIa or anti-gp 53. Significant platelet activation due to unfractionated heparin could be observed by labeling with anti-GMP 140 (UFH: p=0.009; LMWH: p=0.16). The proportion of platelets with surface-bound fibrinogen was significantly increased (UFH: p=0.00006; LMWH: p=0.008). After incubation with heparins, activation ability of platelets by adenosine diphosphate (ADP) was significantly increased. The potentiating action of unfractionated heparin was larger. Therefore, flow cytometric results of platelet activation in patients receiving heparin should be interpreted carefully.
Klein
Bernd
B
Department of Gynecology and Obstetrics, University Hospital of the University of Technology (RWTH), Pauwelsstrasse 30, 52074, Aachen, Germany. bernd.klein@post.rwth-aachen.de
Faridi
Andreé
A
von Tempelhoff
G F
GF
Heilmann
Lothar
L
Mittermayer
Christian
C
Rath
Werner
W
D000244:Adenosine Diphosphate / Q000494:pharmacology; D000328:Adult; D001769:Blood; D005340:Fibrinogen / Q000032:analysis / Q000187:drug effects; D005434:Flow Cytometry; D006493:Heparin / Q000494:pharmacology*; D006495:Heparin, Low-Molecular-Weight / Q000494:pharmacology; D006801:Humans; D019007:P-Selectin / Q000032:analysis / Q000187:drug effects; D015539:Platelet Activation / Q000187:drug effects*
D006495:Heparin, Low-Molecular-Weight; D019007:P-Selectin; D000244:Adenosine Diphosphate; D005340:Fibrinogen; D006493:Heparin