Increased plasma von Willebrand factor antigen levels but normal von Willebrand factor cleaving protease (ADAMTS13) activity in preeclampsia
Attila Molvarec1; János Rigó Jr.1; Tamás Bõze1; Zoltán Derzsy1; László Cervenak2; Veronika Makó3; Tímea Gombos3; Miklós László Udvardy4; Jolán Hársfalvi4; Zoltán Prohászka2,3
11st Department of Obstetrics and Gynecology, Semmelweis University, Budapest, Hungary; 2Research Group of Inflammation Biology and Immunogenomics, Hungarian Academy of Sciences, Budapest, Hungary; 33rd Department of Internal Medicine and Szentágothai Knowledge Center, Semmelweis University, Budapest, Hungary; 4Clinical Research Center, University of Debrecen, Debrecen, Hungary
The activity of ADAMTS13, the von Willebrand factor (VWF) cleaving protease is low in several conditions, including HELLP (haemolysis, elevated liver enzymes, and low platelet count) syndrome. As HELLP syndrome develops in most cases on the basis of preeclampsia, our aim was to determine whether plasma ADAMTS13 activity is decreased in preeclampsia. Sixty-seven preeclamptic patients, 70 healthy pregnant women and 59 healthy non-pregnant women were involved in this case-control study. Plasma ADAMTS13 activity was determined with the FRETS-VWF73 assay, while VWF antigen (VWF:Ag) levels with an enzyme-linked immunosorbent assay. The multimeric pattern of VWF was analyzed by SDS-agarose gel electrophoresis. There was no significant difference in plasma ADAMTS13 activity between the preeclamptic and the healthy pregnant and nonpregnant groups (median [25–75 percentile]: 98.8 [76.5–112.8] %, 96.3 [85.6–116.2] % and 91.6 [78.5–104.4] %, respectively; p>0.05). However, plasma VWF:Ag levels were significantly higher in preeclamptic patients than in healthy pregnant and non-pregnant women (187.1 [145.6–243.1] % versus 129.3 [105.1–182.8] % and 70.0 [60.2–87.3] %, respectively; p<0.001). The multimeric pattern of VWF was normal in each group. Primiparas had lower plasma ADAMTS13 activity than multiparas (92.6 [75.8–110.6] % versus 104.2 [92.1–120.8] %; p=0.011). No other relationship was found between clinical characteristics, laboratory parameters and plasma ADAMTS13 activity in either study group. In conclusion, plasma ADAMTS13 activity is normal in preeclampsia despite the increased VWF:Ag levels. However, further studies are needed to determine whether a decrease in plasma ADAMTS13 activity could predispose preeclamptic patients to develop HELLP syndrome.
pregnancy, von Willebrand factor, ADAMTS13, preeclampsia, HELLP syndrome