F8 and venous thromboembolism: To minimalize the confounding influence of any postthrombotic acute phase response FVIII levels should be measured 3–6 months following the acute venous thromboembolism.9 Current data suggest that the high FVIII levels do not simply reflect a postthrombotic acute phase response, which can contribute to the elevation of fibrinogen, CRP, and FVIII.