Effects of enoxaparin on myeloperoxidase release during hemodialysis

Area of Science:

• Biochemistry
• Nephrology
• Pharmacology

Background:

• Myeloperoxidase (MPO) is a prooxidant enzyme associated with the vascular wall.
• Heparin-binding proteins, like MPO, may be affected by heparin administration.
• Hemodialysis (HD) often requires anticoagulation to prevent clotting.

Purpose of the Study:

• To investigate if enoxaparin, a low-molecular-weight heparin used for HD anticoagulation, causes systemic MPO activation.
• To determine the relationship between enoxaparin dosage and MPO levels.
• To compare MPO activation during enoxaparin-anticoagulated HD versus heparin-free HD.

Main Methods:

• Plasma MPO levels were measured in patients undergoing maintenance HD.
• Patients received an intravenous bolus of enoxaparin for anticoagulation.
• MPO levels were retested during HD using heparin-grafted dialyzers without systemic enoxaparin.

Main Results:

• Plasma MPO levels increased significantly during enoxaparin-anticoagulated HD (8.6-fold at 10 min, 3.3-fold at 120 min).
• MPO increases were dose-dependent on enoxaparin and inversely related to baseline MPO levels.
• MPO increase was less pronounced during systemic heparin-free HD.

Conclusions:

• Enoxaparin administration during HD induces a marked, dose-dependent increase in plasma MPO.
• This MPO increase is likely due to its liberation from the vascular wall.
• The findings suggest a potential mechanism for MPO activation related to heparin use in hemodialysis.