Protein adsorption during LDL-apheresis: proteomic analysis

Area of Science:

• Biochemistry
• Proteomics
• Medical Technology

Background:

• Low-density lipoprotein apheresis (LDL-A) is used to remove LDL cholesterol.
• The impact of different LDL-A methods on functional protein clearance is not fully understood.
• Proteomic analysis offers a comprehensive approach to study protein interactions.

Purpose of the Study:

• To investigate the clearance of functional proteins by various LDL-A methods.
• To compare protein loss across different LDL-A techniques using proteomic and laboratory analyses.

Main Methods:

• Proteins eluted from LDL-A columns were analyzed using 2D electrophoresis and mass spectrometry.
• Plasma protein loss was quantified in patients undergoing double-filtration plasmapheresis (DFPP), direct adsorption of lipoproteins (DALI), and heparin-induced extracorporeal LDL precipitation (HELP).
• Routine laboratory methods and western blots were employed for quantification.

Main Results:

• Proteomic analysis showed column-type dependent protein loss, with DALI exhibiting the highest (1001 +/- 36 spots), followed by HELP (881 +/- 25 spots) and DFPP (535 +/- 20 spots).
• Over 70 functional proteins were identified, including those involved in coagulation, adhesion, rheology, and immunity.
• Western blot analysis confirmed significant depletion of these proteins post-treatment, indicating systemic lowering.

Conclusions:

• LDL-A methods result in significant interaction and clearance of functional serum proteins.
• The removal of proteins with adhesive, rheological, and inflammatory properties may benefit microcirculation and reduce inflammation.
• Potential side effects include an increased risk of bleeding due to the depletion of certain functional proteins.