Effects of red blood cells on hemostasis.
BACKGROUND
Currently there is no sensitive laboratory test to establish the influence of red blood cells (RBCs) on hemostasis. As thromboelastography (TEG) measures hemostasis in whole blood, taking into account the interactions of all cellular elements, we used this instrument to investigate the role that RBCs play in hemostasis.


METHODS
In 29 patients with chemotherapy-induced anemia we studied the effect of progressive anemia on the coagulation profile. In 24 patients with chronic anemia we studied the effect of transfusion of RBCs on coagulation. Finally, in 18 patients we evaluated whether storage time of RBCs has additional effects on hemostasis.


RESULTS
We observed a significant negative correlation between hemoglobin and TEG variables related to both clot strength and elasticity (p < 0.05). Moreover, anemia was associated with a delay in the initiation of the coagulation cascade. Correction of anemia by RBC transfusion resulted in significant shortening of this initiation phase with now the opposite effect on clot strength and elasticity. The negative effects on clot quality were significantly worse when fresh RBCs were transfused compared to longer-stored RBCs. Furthermore, in contrast to the longer-stored RBCs, fresh RBCs did not enhance initial fibrin formation.


CONCLUSIONS
In this study we found that anemia was associated with a delay in the initiation of the coagulation cascade with a finally formed clot with superior strength and viscoelastic properties. Transfusion of RBCs was associated with impaired clot quality, with even worse effects on the initial fibrin build-up and clot quality by fresh RBCs.
Roeloffzen
Wilfried W H
WW
Department of Hematology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands.
Kluin-Nelemans
Hanneke C
HC
Bosman
Lotte
L
de Wolf
Joost Th M
JT
D000328:Adult; D000368:Aged; D000740:Anemia / Q000097:blood; D001792:Blood Platelets / Q000502:physiology; D017707:Erythrocyte Transfusion; D004912:Erythrocytes / Q000502:physiology*; D005260:Female; D006454:Hemoglobins / Q000032:analysis; D006487:Hemostasis; D006801:Humans; D008297:Male; D008875:Middle Aged; D013916:Thrombelastography
D006454:Hemoglobins