The purpose of this study was to compare the ability of flesh and cryo
preserved mononuclear cells to generate thrombin, induce fibrin format
ion and finally resolve the fibrin formed, when exposed to plasma. Per
ipheral blood mononuclear cells (PBM) from 4 donors were collected by
gradient centrifugation on Lymfoprep, and cryopreserved in fetal calf
serum and 10% dimethyl sulfoxide. Viability was tested by exclusion of
trypan blue, as well as green/red fluorescence of fluorescein-diaceta
te and ethidium bromide (FDA/EB). Fresh and frozen-thawed cells were s
eeded, stimulated with lipopolysaccharide (LPS), and exposed to a stan
dard heparinized overlay plasma. Plasma was harvested at intervals (0-
7 days). Thrombin generation and fibrin formation were measured by qua
ntification of prothrombin fragment (F1+2) and fibrinopeptide A (FPA)
and the fibrinolytic capacity of the cells as the amount of fibrin(oge
n) degradation products (FbDP and FgDP). Recovery of cells after thawi
ng was about 80%, and the viability of fresh and cryopreserved PBM was
>95%. Compared to fresh, frozen cells fully retained their capability
of Tissue Factor synthesis, leading to prothrombinase activity (F1+2)
and fibrin formation (FPA). In contrast, the fibrinolytic capacity of
frozen-thawed cells were significantly reduced. As expected there wer
e significant variations between the donors in all the parameters meas
ured. We conclude that cryopreservation of human blood mononuclear cel
ls is possible with maintainance of the potential of the cells to medi
ate coagulation in plasma upon LPS stimulation, whereas the fibrin res
olving capacity apparently is reduced by the preservation procedure.