Opsonic dysfunction secondary to plasma fibronectin depletion after aortic surgery

Area of Science:

• Biochemistry
• Immunology
• Surgical Research

Background:

• Fibronectin (FN) is a crucial plasma opsonin involved in immune response.
• Major injury or surgery can lead to a significant decrease in plasma FN levels.
• Understanding FN dynamics post-surgery is vital for assessing patient outcomes.

Purpose of the Study:

• To investigate the impact of major aortic surgery on plasma fibronectin levels in patients and a porcine model.
• To determine the relationship between FN depletion, circulating debris, and mortality.
• To highlight the clinical significance of assessing bound vs. free fibronectin.

Main Methods:

• Plasma FN levels were measured pre- and post-aortic surgery in human patients and pigs.
• A porcine model was used to induce surgical shock and study FN consumption.
• Circulating FN complexes and collagenous debris were analyzed using kDa measurements.

Main Results:

• Aortic surgery caused a significant drop in plasma FN in both patients (363 to 179 mg/l) and pigs (331 to 43 mg/l).
• Herniorrhaphy did not result in significant FN depletion.
• Low FN levels (<190 mg/l) correlated with FN consumption in 1000 kDa complexes containing debris.
• Severe FN depletion was linked to higher debris concentrations and increased mortality in pigs.

Conclusions:

• Major surgery, particularly aortic procedures, leads to substantial plasma fibronectin depletion.
• This depletion can result in clinically significant opsonic dysfunction.
• Accurate assessment of fibronectin's clinical relevance requires measuring both free and complex-bound forms.