Intraperitoneal fibrin-formation and its inhibition in CAPD.

Area of Science:

• Biochemistry
• Nephrology
• Hematology

Background:

• Fibrin formation is a concern in continuous ambulatory peritoneal dialysis (CAPD).
• Heparin is used to inhibit fibrin formation during CAPD.
• The mechanism of heparin's action in the peritoneal cavity requires further investigation.

Purpose of the Study:

• To investigate intraperitoneal fibrin formation and its inhibition by heparin in CAPD patients.
• To determine the concentration and behavior of heparin and antithrombin III in the peritoneal dialysate.
• To assess the role of antithrombin III in heparin-mediated fibrin inhibition.

Main Methods:

• Six CAPD patients were studied.
• Intraperitoneal heparin (5000 U) was administered.
• Concentrations of heparin, antithrombin III, and fibrinopeptide A were measured in plasma and dialysate over a 4-hour dwell time.
• In vitro experiments assessed fibrin formation inhibition by heparin without antithrombin III.

Main Results:

• Intraperitoneal heparin concentration decreased over 4 hours.
• Antithrombin III concentration in dialysate increased and was sufficient for its function.
• Fibrinopeptide A levels were significantly elevated in dialysate during regular CAPD but decreased after heparin administration.
• Heparin showed minimal fibrin inhibition in vitro without antithrombin III.

Conclusions:

• Fibrin formation, indicated by elevated fibrinopeptide A, occurs intraperitoneally in CAPD patients.
• Antithrombin III present in the dialysate is sufficient to potentiate heparin's anticoagulant effect.
• Intraperitoneal heparin effectively inhibits fibrin formation in CAPD by accelerating the action of antithrombin III.