The procoagulant activity of red blood cells from patients with severe preeclampsia.
OBJECTIVE
Our purpose was to determine whether red blood cells from patients with severe preeclampsia may exhibit increased membrane exposure of procoagulant phospholipids (i.e., phosphatidylserine), which may initiate intravascular clotting and platelet activation.


METHODS
The study group comprised 28 women: 9 with severe preeclampsia in the third trimester of pregnancy, 10 normotensive with uncomplicated pregnancies, and 9 age-matched, nonpregnant, healthy women. The exposure of phosphatidylserine on the outer membrane phospholipid layer was analyzed with use of isolated, washed red blood cells that were added as a source of phospholipids to a "prothrombinase" coagulation complex.


RESULTS
The resultant thrombin formed was measured by an amidolytic assay. Thrombin generation significantly increased on the addition of red blood cells from women with preeclampsia (741 +/- 132 mU/ml/min) compared with red blood cells from normotensive pregnant (422 +/- 228 mU/ml/min) and nonpregnant women (316 +/- 268 mU/ml/min, p = 0.0008).


CONCLUSIONS
This study indicates that in patients with preeclampsia the red blood cells exhibit a significant procoagulant surface that may trigger thrombin formation, thereby playing a role in the hypercoagulable state.
Grisaru
D
D
Department of Obstetrics and Gynecology A, Serlin Maternity Hospital, Tel Aviv, Israel.
Zwang
E
E
Peyser
M R
MR
Lessing
J B
JB
Eldor
A
A
D000328:Adult; D000818:Animals; D001777:Blood Coagulation / Q000502:physiology*; D002417:Cattle / Q000097:blood; D004912:Erythrocytes / Q000378:metabolism / Q000502:physiology*; D005260:Female; D006801:Humans; D011225:Pre-Eclampsia / Q000097:blood*; D011247:Pregnancy; D011516:Prothrombin / Q000096:biosynthesis; D012016:Reference Values; D013917:Thrombin / Q000096:biosynthesis
D011516:Prothrombin; D013917:Thrombin