Thromb Haemost 1999; 81(05): 680-683
DOI: 10.1055/s-0037-1614553
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Increased Levels of Factor VIII and Fibrinogen in Patients with Venous Thrombosis Are not Caused by Acute Phase Reactions

Pieter W. Kamphuisen
1   From the Hemostasis and Thrombosis Research Center
,
Jeroen C. J Eikenboom
1   From the Hemostasis and Thrombosis Research Center
,
Hans L. Vos
1   From the Hemostasis and Thrombosis Research Center
,
Renee Pablo
3   Department of Clinical Chemistry, Leiden University Medical Center, Leiden, The Netherlands
,
Auguste Sturk
3   Department of Clinical Chemistry, Leiden University Medical Center, Leiden, The Netherlands
,
Rogier M. Bertina
1   From the Hemostasis and Thrombosis Research Center
,
Frits R. Rosendaal
1   From the Hemostasis and Thrombosis Research Center
2   Department of Clinical Epidemiology, Leiden University Medical Center, Leiden, The Netherlands
› Author Affiliations

This study was supported by a grant (No 950-10-629) from the Netherlands Organisation for Scientific Research (NWO).
Further Information

Publication History

Received 14 December 1998

Accepted 25 January 1999

Publication Date:
09 December 2017 (online)

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Summary

Factor VIII activity (factor VIII:C) levels ≥150 IU/dl are associated with a 5- to 6-fold increased risk of venous thrombosis compared to levels <100 IU/dl, and fibrinogen levels ≥5.0 g/l increase the thrombosis risk 4-fold. These high levels are present in 25% resp. 3% of the patients with a first episode of venous thrombosis. These findings were based on measurements after the thrombotic event, so the factor VIII and fibrinogen levels in thrombosis patients may have been influenced by acute phase reactions or ongoing inflammatory responses. In the present study we measured plasma C-reactive protein (CRP) as a sensitive marker of an acute phase reaction in 474 thrombosis patients and 474 age- and sex-matched healthy controls, that were part of the Leiden Thrombophilia Study (LETS). Mean and median CRP levels were higher in thrombosis patients than in the controls, suggesting inflammation in some patients. CRP affected both factor VIII and fibrinogen levels, in patients and controls alike. After adjustment for the effect of CRP, high factor VIII:C levels still increased the thrombosis risk 6-fold and high fibrinogen levels 4-fold, which is for both very similar to the risk before correction for CRP levels. These results show that although systemic inflammation may be present in some of the patients, elevated levels of factor VIII:C and fibrinogen were in general not caused by acute phase reactions. This further supports a causal relationship between both high factor VIII:C and fibrinogen levels and venous thrombosis.