Oxidized Phospholipids Are Present on Plasminogen, Affect Fibrinolysis and Increase Following Acute Myocardial Infarction

This study identified oxidized phospholipids (OxPL) covalently bound to plasminogen — making plasminogen a second major plasma carrier of OxPL distinct from lipoprotein(a) — and demonstrated that these OxPL functionally impair clot lysis.

Enzymatic removal of OxPL from plasminogen prolonged clot lysis time by 36 percent, indicating that OxPL-laden plasminogen is less fibrinolytic than native plasminogen. In AMI patients, OxPL/plasminogen levels rose acutely in the first 24 hours and remained elevated for days — a dynamic, reactive response absent from the more stable OxPL/Lp(a) signal.

The clinical implication is mechanistically important. Plasminogen and apo(a) — the protein component of Lp(a) — are structurally homologous, both containing kringle sequences that compete at sites of fibrin formation. The finding that OxPL impair plasminogen-mediated fibrinolysis in AMI provides a distinct mechanism for impaired natural thrombolysis in the acute setting, potentially explaining why some clots resist lysis more effectively than others.

We rate the evidence strong. Rigorous translational biochemistry revealing an OxPL-plasminogen axis with direct relevance to thrombosis and fibrinolysis in acute coronary syndromes — extending the OxPL biology beyond Lp(a) to the broader clot resolution system.