The amplitude of coagulation curves from thrombin time tests allows dysfibrinogenemia caused by the common mutation FGG-Arg301 to be distinguished from hypofibrinogenemia.
BACKGROUND
Thrombin time (TT) tests are useful for diagnosing coagulation disorders involving abnormal fibrinogen but do not allow us to distinguish between qualitative and quantitative defects. However, with the widening availability of optical coagulation automates, more information about the coagulation process is becoming increasingly accessible.


METHODS
In this study, we compared the coagulation curves of TT tests carried out with plasma from healthy donors with those from patients with acquired low Clauss fibrinogen levels or with dysfibrinogenemia caused by a heterozygous point mutation in the fibrinogen γ-chain that results in a p.Arg301(275)Cys substitution. The functional fibrinogen levels of these three groups of samples were also measured with the Clauss method, and their fibrinogen protein levels were determined by ELISA.


RESULTS
Our data indicate that the amplitude and maximal velocity of coagulation curves from plasma samples from FGG p.Arg301(275)Cys dysfibrinogenemic patients were comparable to those from plasma samples with fibrinogen in the normal range, whereas the amplitude of coagulation curves from patients with acquired low fibrinogen levels was lower.


CONCLUSIONS
Examination of the amplitude of coagulation curves generated during TT tests may provide additional information to enable the differential diagnoses of diseases following a low fibrinogen measurement by the Clauss method.
Center for Molecular and Vascular Biology, University of Leuven, Leuven, Belgium.|Laboratorium Geneeskunde, UZ Leuven, Leuven, Belgium.
M
M
Jacquemin
Laboratorium Geneeskunde, UZ Leuven, Leuven, Belgium.
I
I
Vanlinthout
Laboratorium Geneeskunde, UZ Leuven, Leuven, Belgium.
I
I
Van Horenbeeck
Laboratorium Geneeskunde, UZ Leuven, Leuven, Belgium.
M
M
Debasse
Laboratorium Geneeskunde, UZ Leuven, Leuven, Belgium.
J
J
Toelen
Laboratorium Geneeskunde, UZ Leuven, Leuven, Belgium.
J
J
Schoeters
Center for Molecular and Vascular Biology, University of Leuven, Leuven, Belgium.
R
R
Lavend'homme
Center for Molecular and Vascular Biology, University of Leuven, Leuven, Belgium.
K
K
Freson
Center for Molecular and Vascular Biology, University of Leuven, Leuven, Belgium.|Vascular Medicine and Haemostasis, UZ Leuven, Leuven, Belgium.
K
K
Peerlinck
D000347:Afibrinogenemia / Q000097:blood* / Q000235:genetics*; D019943:Amino Acid Substitution; D005260:Female; D015241:Fibrinogens, Abnormal / Q000235:genetics* / Q000378:metabolism*; D006801:Humans; D008297:Male; D020125:Mutation, Missense; D013918:Thrombin Time / Q000379:methods
D015241:Fibrinogens, Abnormal; C527521:fibrinogen gamma'
Coagulation; fibrinogen