Studies on prothrombin complex concentrates contact factors, complement components and proteinase inhibitors

Area of Science:

• Biochemistry
• Hematology
• Immunology

Background:

• Prothrombin complex concentrates (PCC) are crucial for treating coagulation factor deficiencies.
• Understanding the behavior of contact factors, complement components, and antiproteases during PCC preparation is vital for safety and efficacy.
• DEAE-Sephadex adsorption is a common method for purifying clotting factors.

Purpose of the Study:

• To investigate the behavior of contact factors, complement components, and antiproteases during PCC preparation using DEAE-Sephadex adsorption.
• To assess the impact of pre-elution salt concentration on the removal and enrichment of these components.
• To evaluate potential molecular alterations and undesirable proteolytic events during the process.

Main Methods:

• Prothrombin complex concentrates were prepared by adsorbing clotting components onto DEAE-Sephadex.
• Contact factors (factors XII, XI, prekallikrein) were removed by pre-elution based on salt concentration.
• Levels of high molecular weight kininogen, complement components (C1s, C3, C4), antiproteases (antithrombin III, alpha 2M, alpha 2 antiplasmin), C1-inactivator, and inter-alpha-trypsin inhibitor were quantified.
• Non-Activated Partial Thromboplastin Time (NAPTT) ratios were assessed to evaluate thrombogenic potential.

Main Results:

• Contact factors (factors XII, XI, prekallikrein) were effectively removed by pre-elution.
• High molecular weight kininogen and complement C4 were significantly enriched in PCC preparations.
• C1s levels increased 4-5 fold, while C3 levels decreased to 30% of plasma concentration.
• Antithrombin III, alpha 2M, and alpha 2 antiplasmin were absent; C1-inactivator and inter-alpha-trypsin inhibitor showed significant increases (3-fold and 15-fold, respectively).
• Molecular alterations of high molecular weight kininogen and C4 were observed.
• Complex formation between C1-inactivator and proteases indicated undesirable proteolytic events.

Conclusions:

• DEAE-Sephadex adsorption is effective in removing contact factors but leads to enrichment of high molecular weight kininogen and complement C4 in PCC.
• The preparation process results in altered levels of complement components and antiproteases, with potential for undesirable proteolytic activity.
• A minimal pre-elution molarity of 0.20 M NaCl is necessary to ensure NAPTT ratios below thrombogenic values.