Comparison of 125I-fibrinogen kinetics and fibrinopeptide A in patients
with disseminated neoplasias
G Mombelli, A Roux, A Haeberli and PW Straub
To provide more information on the pathways of fibrinogen catabolism in
generalized cancer, the effect of heparin on fibrinopeptide A (fpA) and on
125I-fibrinogen kinetics was studied in 15 patients with disseminated
neoplasia. Three patients had evidence of venous thrombosis and in 2
additional patients a low fibrinogen level together with increased amounts
of FDP/fdp and a positive ethanol test indicated disseminated intravascular
coagulation (DIC). The plasma levels of fpA were grossly elevated (4.6--20,
mean 11.4 ng/ml, normal values 1.01 +/- 0.45 ng/ml) in patients with
thrombosis or DIC, and normal to grossly elevated (0.4--10.4, mean 6.1
ng/ml) in the other patients. Intravenous heparin bolus lowered the fpA
level in 11/11 patients, and continuous heparin treatment led to an
impressive suppression or complete normalization of the plasma fpA in 5/6
patients. This finding is thought to reflect heparin suppression of
thrombin activity on fibrinogen. In some cases, the fpA fall after heparin
bolus was slow and/or incomplete, suggesting fpA generation at sites not
easily accessible to heparin or insufficient heparin dosage. The 125I-
fibrinogen kinetics were characterized by a significantly shorter half-
life (t1/2: 2.5 days), increased catabolic rate constant (j: 0.44 days- 1),
and increased absolute turnover (68.9 mg fibrinogen/kg/day) as compared to
4 normal subjects (t1/2: 4.2 days; j: 0.26 days-1; turnover 21.7 mg
fibrinogen/kg/day). As estimated from the fpA generation rates,
intravascular thrombin action on fibrinogen contributed only in minor part
to increase the turnover of 125I-fibrinogen. In particular, the turnover
was greatly accelerated in heparin-treated patients despite impressive
suppression or normalization of the fpA levels in 5/6 cases.
Volume 60,
Issue 2,
pp. 381-388,
08/01/1982
Copyright © 1982 by The American Society of Hematology
