Complement terminal pathway inhibition reduces peritoneal injuries in a rat peritonitis model

Area of Science:

• Nephrology
• Immunology
• Pathology

Background:

• Peritoneal dialysis (PD) is limited by peritonitis and peritoneal injuries in end-stage kidney disease patients.
• Previous research linked complement system activation to PD-associated peritoneal injury, focusing on early pathways.
• The complement terminal pathway's role in PD-associated peritoneal injury requires further investigation.

Purpose of the Study:

• To investigate the role of the complement terminal pathway and membrane attack complex (MAC) formation in PD-associated peritoneal injury.
• To evaluate the efficacy of a novel mAb 2H2 that blocks MAC assembly in a rat peritonitis model.

Main Methods:

• A fungal rat peritonitis model (Zy/MGO) was established using zymosan and methylglyoxal.
• Rats were treated with mAb 2H2 targeting C5b-7 (2.5 or 5 mg/rat) or isotype control.
• Peritoneal injury was assessed macroscopically and microscopically, including peritoneal thickness, inflammatory cell accumulation, and deposition of fibrinogen, C3, and MAC.

Main Results:

• mAb 2H2 treatment dose-dependently and frequency-dependently reduced peritoneal thickness and inflammatory cell accumulation.
• These reductions were associated with decreased deposition of C3, MAC, and fibrinogen in the peritoneum.
• Isotype control antibody did not show these protective effects.

Conclusions:

• Complement terminal pathway activation and MAC formation significantly contribute to peritoneal injury development in the rat Zy/MGO model.
• Targeting MAC formation with therapies like mAb 2H2 may be a promising strategy for preventing peritoneal injuries in PD patients.
• Further research into MAC-targeted therapies could improve long-term outcomes for patients undergoing peritoneal dialysis.