Evidence of the escape of antithrombin from the blood into the interstitial space in pregnant women

Abstract

antithrombin escapes from the blood into the interstitial space in pregnant women. This phenomenon partially explains the gradual decline in antithrombin activity observed in these six pregnant women with generalized edema and large volumes of ascites.

Association of Antithrombin Activity with Plasma Aldosterone Concentration and Plasma Renin Activity in Pregnant Women

“…A modest decrease in the plasma volume is usually difficult to anticipate in clinical practice in the absence of hypertension. This study, as well as the results of previous studies [7,20], suggests that the AT activity reflects the degree of the plasma volume contraction during pregnancy.…”

“…However, the circulating blood volume is markedly reduced in women with preeclampsia [10] and is lowest among women progressing to eclampsia [19]. Although the precise mechanisms leading to the contraction of the circulating plasma volume are not well understood, an increased blood vessel permeability in response to vascular endothelial cell dysfunction allowing the leakage of the plasma into the extravascular space may be one of the possible explanations [20].…”

“…As the determination of AT activity is part of the routine work-up for patients who are admitted to the intensive care unit [22], the determination of AT activity may be easier to perform than the determination of the PRA in most clinical laboratories. The AT molecule moves from the blood into extravascular spaces in the presence of an increased blood vessel permeability, implying that the AT activity in the blood reflects the degree of blood vessel permeability [20]. A modest decrease in the plasma volume is usually difficult to anticipate in clinical practice in the absence of hypertension.…”

Risk Factors of Eclampsia Other Than Hypertension: Pregnancy-Induced Antithrombin Deficiency and Extraordinary Weight Gain

“…Liver dysfunction with transient thrombocytopenia and a transient elevation in serum LDH, namely HELLP syndrome, is considered to be a severe condition irrespective of the degree of hypertension [18]. Patients with edema and/or PIATD may be at an increased risk of developing eclampsia irrespective of the degree of hypertension based on the following reasons: (i) edema can result from enhanced vascular permeability [6]; (ii) cerebral edema is a characteristic finding on magnetic resonance imaging (MRI) in patients with eclampsia [4,10,23]; (iii) vascular permeability is thought to be enhanced in patients with PIATD [8,17]; (iv) a lower antithrombin activity possibly reflects an enhanced vascular permeability [8,16,17]; and (v) patients with either PIATD or eclampsia are likely to develop HELLP syndrome [13,20]. Accordingly, we conducted this retrospective study to determine whether women with eclampsia are likely to exhibit PIATD and/or abnormal weight gain prior to an eclamptic fit.…”

Association of antenatal antithrombin activity with perinatal liver dysfunction: A prospective multicenter study

“…Decreased circulating plasma volume can cause inadequate blood perfusion to the liver leading to liver dysfunction, as seen in women with HELLP syndrome . AT also escapes from the blood into the interstitial space in the presence of enhanced vascular permeability . In an animal model, a protective role of AT against liver dysfunction due to its anticoagulant and anti‐inflammatory action is suggested .…”