[Soluble P-selectin - a marker of platelet activation and vessel wall injury: increase of soluble P-selectin in plasma of patients with myocardial infarction, massive atherosclerosis and primary pulmonary hypertension].

Aim: A comparative analysis of the content of the soluble form of cell adhesion protein P-selectin in the blood plasma of patients with acute myocardial infarction (AMI), massive atherosclerosis (MA) and primary pulmonary hypertension (PPH), investigation of the relationship between plasma content of P-selectin and known markers of platelets and endothelial cells activation, preliminary assessment of the prognostic value of P-selectin determination.

Materials And Methods: This study included 16 patients with AMI, 20 patients with MA, 21 patients with PPH and 18 healthy donors. The follow-up was 1-5 years. End-points in the group of patients with AMI were recurrent acute coronary syndrome and coronary artery by-pass operation, in the group with MA--thrombotic complications (acute coronary syndrome, ischemic stroke) and in the group with PPH--death. P-selectin was measured by ELISA and platelet factor 4 (PF4), thromboxane B2 (TXB2), endothelin-I and stable prostacyclin metabolite 6-keto-prostaglandin F1 alpha (6-keto-PGF1 alpha) by means of commercial ELISA kits.

Results: Mean level of P-selectin in blood plasma of patients with AMI (1 day) (361 +/- 18 ng/ml), MA (410 +/- 31 ng/ml) and PPH (627 +/- 83 ng/ml) was increased in comparison with the group of healthy donors (269 +/- 12 ng/ml) (everywhere p < 0.001). In AMI, P-selectin was increased on day 1 only, on days 2, 3 and 10-14 of the disease the level of P-selectin was significantly lower than on day 1 and did not differ from the control level in the group of donors. In patients with MA a significant correlation was detected between plasma content of P-selectin and platelet activation marker PF4 (r = 0.606, P = 0.007) and in patients with PPH between the content of P-selectin and another platelet activation marker TXB2 (r = 0.622, p = 0.013). However, no correlation was found in PPH patients between the content of P-selectin and markers of endothelial activation and/or damage (endothelin-1 and 6-keto-PGF1 alpha). Difference in the concentration of P-selectin in patients with or without end-points during the follow-up period was detected in patients with AMI (353 +/- 14 ng/ml and 451 +/- 24 ng/ml, p = 0.009) and PPH (477 +/- 58 ng/ml and 927 +/- 184 ng/ml, p = 0.017) but not with MA (426 +/- 37 ng/ml and 361 +/- 24 ng/ml, p = 0.295).

Conclusion: The level of P-selectin in plasma was increased in patients with acute thrombosis (AMI, 1 day) as well as in patients without clinical signs of thrombosis but with a massive injury of the vasculature (MA and PPH). The increase of P-selectin was, presumably, caused by its secretion from activated platelets since its concentration in plasma correlated with platelet concentration but not endothelial activation markers. Preliminary data indicate that blood plasma soluble P-selectin may be considered as a potential prognostic marker in AMI and PPH.