Abstract
Fibrinopeptide A (FPA) was measured in human plasma by a radioimmunoassay kit (IMCO). In 14 normal individuals this assay revealed a mean FPA level of 1.5ng/ml. 121 patients were divided into 6 groups by the levels of fibrinogen and FDP as follows.
A. Patients with elevated fibrinogen levels and elevated FDP levels (n=16)
B. Patients with elevated fibrinogen levels and normal FDP levels (n=13)
C. Patients with normal fibrinogen levels and elevated FDP levels (n=17)
D. Patients with normal fibrinogen levels and normal FDP levels (n=44)
E. Patients with reduced fibrinogen levels and elevated FDP levels (n=7)
F. Patients with reduced fibrinogen levels and normal FDP levels (n=24)
The mean FPA levels were, 9.4ng/ml in group A, 3.7ng/ml in group B, 3.9ng/ml in group C, 5.3ng/ml in group D, 4.1ng/ml in group E, and 4.8ng/ml in group F, respectively. These results indicated that elevated FPA levels were found in the patients with normal fibrinogen levels and normal FDP levels. Considering FPA levels from clinical disorders, elevated FPA levels were found in patients suffering from Dis-seminated intravascular coagulation, leukemia, malignant neoplasma, pulmonary embolism and other thrombotic disorders. After injection of heparin in the patients with these disorders, FPA level was reduced rapidly into the normal range.
These results suggest that FPA is most sensitive indicator of thrombin action, and provides direct information concerning the effectiveness of therapy in preventing fibrin formation.
