Assessment of annexin A5 and annexin A2 levels as biomarkers for pre-eclampsia: A pilot study

Deficient anticoagulant activity of annexin A5 and deficient profibrinolytic activity of annexin A2 have been linked to increased risk of thrombotic events. Placental dysfunction due to fibrin deposition/microthrombi has been implicated in the pathogenesis of pre-eclampsia (PE). In this study, we aimed to assess serum levels of annexin A5 and annexin A2 in a cohort of PE patients and investigate their role as biomarkers for the development of the disease. We examined 80 women in total; 40 healthy pregnant women and 40 pregnant women with PE after 20 weeks of pregnancy. Women were subjected to full clinical assessment, ultrasonography, and laboratory testing including complete blood picture, liver and kidney function tests and assessment of serum and urine proteins. Annexin A5 and annexin A2 were analyzed using enzyme-linked immunosorbent assay. The study showed serum annexin A2 but not annexin A5 was significantly reduced (P = 0.029) in women with PE (total and severe cases) compared to those with normal pregnancy. The ROC analysis of annexin A2 level for the prediction of development of PE showed an area under the curve of 0.64 (P = 0.029), and the best cut-off value was 0.89 ng/ml with a sensitivity of 70.0% and a specificity of 70.0%. Univariate analysis showed annexin A2 of <0.89 ng/ml, proteinuria, lower platelet count and higher BP were associated with significantly higher risk to develop PE. Based on this pilot study, serum annexin A2 levels may be a useful biomarker for pre-eclampsia. However, a larger study is required before a final conclusion is made.