Related Experiment Videos
Complement activation during tryptophan immunoadsorption treatment
A A Alarabi1, B Nilsson, U Nilsson
1Department of Internal Medicine, University Hospital, Uppsala, Sweden.
Artificial Organs
|September 1, 1993
Summary
This study introduces a new extracorporeal treatment to remove anti-human lymphocyte antigen (HLA) antibodies before kidney transplants. The immunoadsorption column (IM-TR) treatment activates complement, generating C3d fragments that may reduce antibody levels.
Area of Science:
- Nephrology
- Immunology
- Transplantation Science
Background:
- Antibodies against human lymphocyte antigens (HLA) pose a significant challenge in renal transplantation, often necessitating pre-transplant antibody removal.
- Plasmapheresis is a common method for reducing these antibodies, but novel extracorporeal procedures are being explored to improve graft survival.
Purpose of the Study:
- To evaluate a new immunoadsorption column (IM-TR) procedure for removing anti-HLA antibodies in patients awaiting renal transplantation.
- To investigate the mechanisms underlying the reduction of antibody levels during IM-TR treatment.
Main Methods:
- Utilized an immunoadsorption column (IM-TR) with a polyvinyl alcohol (PVA) gel matrix conjugated with tryptophan.
- Treated 7 HLA-immunized patients with 12 IM-TR sessions (3 sessions/week) prior to renal transplantation.
- Monitored immunoglobulin levels and complement activation, specifically the C3d (C3dg) fragment.
Main Results:
- IM-TR treatment showed less direct immunoglobulin depletion compared to plasmapheresis.
- Significant complement activation via the alternative pathway was observed during IM-TR treatment.
- Exceedingly high levels of the complement activation fragment C3d (C3dg) were detected in patient plasma.
Conclusions:
- The reduction in antibody levels during IM-TR treatment may involve mechanisms beyond simple immunoglobulin depletion.
- Extensive generation of C3dg is a key finding, suggesting its potential role in immune response modulation.
- C3dg's known immunoregulatory properties indicate it may contribute to the observed decrease in anti-HLA antibody levels, potentially improving transplant outcomes.