Pré-eclâmpsia: avaliação de fator VIII, fator de Von Willebrand e Adamts-13 e do grupo sanguíneo ABO

Abstract

Pre-eclampsia (PE) pure is characterized by hypertension and proteinuria in normotensive pregnant women after the 20ª week of gestation. The etiology of the PE is not yet known. Its incidence is approximately 10% in primigravidae and this is responsible for high fetal morbidity. The physiological hypercoagulable state in normal pregnancy is even higher in PE. It is known that the ABO blood group is related to the occurrence of thrombotic events, since "non O" (A, B and AB) individuals have increased F VIII and vWF levels comparing to O. ADAMTS-13 is the enzyme responsible for regulating the vWF plasma levels. The aim of this study was to evaluate the activity of F VIII, vWF and ADAMTS-13 plasma levels and ABO blood group with the occurrence of severe PE. It was evaluated 160 women; group I: 60 severe preeclamptic women group II: 50 normotensive pregnant women and group III: 50 non-pregnant women. Pregnancies in groups I and II were divided into two subgroups, with gestational age (GA)29 weeks and GA<29 weeks for hemostatic parameters evaluation. It was evaluated the activity of F VIII, vWF and ADAMTS-13 plasma levels and the frequency of ABO blood group. For pregnant women with gestational age29 weeks, F VIII and vWF were significantly increased in group I compared to II (P=0.01 and P=0.05, respectively). ADAMTS-13 was significantly lower in group I than in group II (P=0.02). The comparison of groups I and III showed an increase in F VIII and vWF in group I (P=0.00 in both cases) and a decrease of ADAMTS-13 (P=0.00). Comparing groups II and III, were observed an increase in F VIII and vWF in group II (P=0.00 in both cases) and a decrease of ADAMTS-13 (P=0.00). The frequency of blood groups among pregnant women with severe PE and normotensive, showed no difference (P=0.69, P=1.00, P=0.78 and P=0.73 for the groups O, A, B and AB, respectively). The activity of F VIII and plasma levels of vWF showed a decreased in women of blood group O compared to those of the group "non O" (P=0.01 and P=0.00, respectively). Plasma levels of ADAMTS-13 were not different comparing the blood group O and "non O" (P=0.13). No difference was found comparing the blood phenotypes O and "non O" for F VIII, vWF and ADAMTS-13 in groups I and II (GA29 weeks and GA<29 weeks). For group III there was a significant increase of F VIII and vWF among "non-O" women comparing to those O. No difference was obtained for ADAMTS-13.To verify the association of clinical, haemostatic and ABO system with the development of the PE, a multivariate regression analysis was made, considering the presence and absence of PE as the dependent variable. The results for haemostatic parameters were: F VIII (OR= 4.02 CI= 1.53-10.55 P= 0.01), vWF (OR= 3.88 CI= 1.45-10.39 P= 0.01) and ADAMTS-13 (OR= 8.77 CI= 2.40-32.06 P= 0.00). These results suggest that a hypercoagulability state is present in PE and it may be resulting from the increased levels of vWF and F VIII activity. ADAMTS-13 levels are reduced in this disease and ABO blood group is not related to its occurrence.