Circulating levels of the anti-angiogenic thrombospondin 2 are elevated in pre-eclampsia

An imbalance of maternal circulating pro- and anti-angiogenic factors may play a role in the pathogenesis of pre-eclampsia. Thrombospondin 2 (TSP-2) is a protein expressed mainly by activated endothelial cells, which acts as a potent anti-angiogenic agent. Our aim was to determine whether serum TSP-2 levels are altered in pre-eclampsia. We enrolled 35 pre-eclamptic patients and 35 healthy pregnant women in the study. Thrombospondin 2 levels were determined by enzyme-linked immunosorbent assay, while soluble fms-like tyrosine kinase-1 (sFlt-1) and placental growth factor (PlGF) concentrations were determined by electrochemiluminescence immunoassay. In patients with PE, we demonstrated 1.7-fold higher TSP-2 [13.2 (9.4-18.1) vs. 7.9 (7.2-11.2) ng/ml, p<0.001], 3.8-fold higher sFlt-1 and 4.3-fold lower PlGF levels compared with the control group. There were no associations between TSP-2 and sFlt-1 or PlGF concentrations. We suggest that circulating TSP-2 levels may contribute to the pathogenesis of PE via its anti-angiogenic properties, but in a distinct way from sFlt-1 and PlGF.