Complement (C5)-derived chemotactic activity in serum from patients with pancreatitis

Area of Science:

• Immunology
• Biochemistry

Background:

• Acute pancreatitis can lead to severe complications, including acute lung injury.
• The complement system plays a role in inflammatory processes.
• Chemotactic factors are crucial in mediating inflammatory cell recruitment.

Purpose of the Study:

• To investigate the presence and characteristics of complement-derived chemotactic activity in acute pancreatitis.
• To explore the potential role of this activity in the pathogenesis of lung injury associated with pancreatitis.

Main Methods:

• Analysis of serum and plasma samples from acute pancreatitis patients.
• Assay for polymorphonuclear neutrophil (PMN) chemotactic activity.
• Measurement of complement component C5 degradation products using radioimmunoelectrophoresis.
• Characterization of chemotactic activity by heat stability, antibody inhibition, and molecular weight determination (Sephadex G-75 chromatography).

Main Results:

• Significant chemotactic activity for human PMN was detected in samples from 5 out of 8 patients.
• This activity correlated with reduced CH50 levels and the presence of C5 degradation products.
• The chemotactic activity was heat-stable, inhibited by anti-C5 antibodies, and had a molecular weight of approximately 16,000 Da, consistent with C5a and/or C5a des Arg.

Conclusions:

• Circulating C5-derived chemotactic peptides are present during acute pancreatitis.
• These peptides may contribute to the pathogenesis of lung injury observed in some pancreatitis patients.
• Further research is warranted to elucidate the precise mechanisms involved.