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Haemostatic factors in human peripheral afferent lymph
G J Miller1, D J Howarth, J C Attfield
1Medical Research Council Epidemiology and Medical Care Unit, London, UK. g.miller@mds.qmw.ac.uk
Thrombosis and Haemostasis
|April 1, 2000
Summary
Vitamin K-dependent factors show altered activity in lymph compared to plasma. Elevated activated factor VII and D-dimer levels in lymph suggest local fibrinolysis in interstitial fluid.
Area of Science:
- Hemostasis and Thrombosis
- Vascular Biology
- Biochemistry
Background:
- Understanding the hemostatic balance in interstitial fluid is crucial for diagnosing bleeding and thrombotic disorders.
- Vitamin K-dependent factors play a key role in the coagulation cascade.
- Previous studies have limited data on the composition of human peripheral lymph regarding coagulation factors.
Purpose of the Study:
- To investigate the concentrations and activities of vitamin K-dependent coagulation factors in human peripheral afferent lymph.
- To compare lymph and plasma levels of specific coagulation factors and their activation markers.
- To explore potential local procoagulant or fibrinolytic activity within the interstitial space.
Main Methods:
- Peripheral afferent lymph was collected from 17 healthy male volunteers via cannulation of a collecting lymphatic vessel.
- Lymph and plasma samples were analyzed for the activity and antigen levels of vitamin K-dependent factors (e.g., Factor VII, Factor IX).
- Concentrations of activated Factor VII (FVIIa), TFPI-Xa complex, fibrinogen (Clauss activity and antigen), and D-dimer were measured using specific assays (e.g., ELISA).
Main Results:
- Lymph/plasma ratios for vitamin K-dependent factors were lower than predicted by molecular weight, indicating selective transfer.
- Activity/antigen ratios for Factor VII, Factor IX, and TFPI were higher in lymph than plasma, suggesting local activation.
- Elevated FVIIa and TFPI-Xa complex concentrations were found in lymph. D-dimer levels were significantly higher in lymph than plasma, often exceeding five-fold.
Conclusions:
- Human peripheral lymph contains significantly altered levels of coagulation factors and activation markers compared to plasma.
- The elevated FVIIa and high D-dimer levels in lymph suggest local activation of the coagulation cascade and ongoing fibrinolysis within the interstitial fluid.
- These findings highlight potential local hemostatic processes occurring beyond the vascular compartment.