Author’s Reply

To the Editor: In her critique of our article, Dr Hoffman states that factor V Leiden and the prothrombin gene mutation were not evaluated in the three patients. They were. The “NP” in the table means “not present” (see key under table).

That factor VIII can be an acute phase reactant seems to be common knowledge. However, I listed 3 references1–3 that specifically examined this in patients with venous thromboembolism (VTE) and concluded that the increase in factor VIII was “persistent and independent of the acute phase response.” O’Donnell et al1 use that specific phrase in their title and find 94% of 35 VTE patients with elevated FVIII to have a persistent increase, independent of CRP and fibrinogen. O’Donnell et al2 found elevated FVIII to be the single most common risk factor in 260 VTE patients and also stated that it did not correlate with CRP or fibrinogen. Kamphuisen et al3 reached the same conclusion. (“Increased levels of FVIII and fibrinogen in patients with VTE are not caused by acute phase reactions.”)

I would have liked to have had CRP and fibrinogen levels on my patients, but this was a retrospective study and none were done.