Background: Antiphospholipid syndrome (APS) is an autoimmune disease characterized by thrombosis and gestational disorders in the presence of antiphospholipid antibodies (aPL). ß2-Glycoprotein l (ß2-GPl) is one of the main antigens recognized by aPL. It is not clear if the basal expression of ß2-GPl is different between different pregnant women, nor if this event could explain the worse clinical outcomes in some patients with alterations such as APS.

Objective: Characterize the expression of ß2-GPl in different clones and cultures passages of human umbilical cord vein endothelial cells (HUVEC) of healthy pregnant women.

Methods: We isolated HUVEC cells by enzymatic and mechanical digestion with type l collagenase and subsequent, we detected CD31 and ß2-GPl expression by flow cytometry and fluorescence microscopy.

Results: ß2-GPl expression varies between HUVEC cells of different clones of healthy pregnant women. For clone one the positivity was 6.25%, while for clones 2 and 3, it was 81.9 and 88.9%, respectively. 

Conclusions: The expression of ß2-GPl in endothelial cells could vary between healthy pregnant women. Therefore, in vitro models for the study of endothelial dysfunction in APS needs to add this cofactor to the culture.