| Research Shows Progress toward Understanding New Mechanisms of Rejection in Heart and Lung ... |
| Written by Alex Hildred |
| Wednesday, 22 April 2009 13:53 |
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Tomorrow's ISHLT morning plenary session will focus on developments related to mechanisms underlying chronic rejection, including the new role of C4d Th17 cells and antibodies. The session will feature an invited lecture by Mohamed H. Sayegh, MD, Professor of Medicine and Pediatrics,Harvard Medical School, who will discuss the role of a special lineage of T helper cells called Th17 cells that promote inflammation causing cardiac allograft rejection and vasculopathy. (April 23, 9:00 am local time, Main Theatre, Palais des Congres). "The newly identified function of Th17 cells in chronic rejection and vasculopathy provides the rationale for the development of new therapeutic targets to combat this process," explained Dr. Sayegh. "There are promising targets that are currently being tested in pre-clinical experimental animal models." A second invited lecture by Elaine F. Reed, PhD, Professor of Pathology, University of California, Los Angeles, will highlight the role of antibodies in influencing functional changes in the cells of the graft that can promote either allograft survival or transplant vasculopathy. AMR and Vasculopathy in Heart and Lung Transplants: AMR has been shown to be associated with significantly lower survival rates and to predispose patients to transplant vasculopathy. AMR can present early or late after transplantation, and is usually associated with a concomitant rise in donor-specific antibodies. Sensitization is the process by which antibodies are formed and patients with antibodies before transplant (pre-sensitized) hold the highest risk of rejection and reduced survival. In detecting AMR, researchers look for markers using a process which stains for complement deposition (C4d and C3d). The presence of donor-specific HLA antibodies can also indicate AMR. Typically a cardiac biopsy is performed when a patient is suspected of having antibody-mediated rejection. A featured abstract to be presented during the session by Carmela Tan, MD, Cleveland Clinic, will describe the importance of complement deposition in heart biopsies to diagnose AMR and the clinical significance. Researchers will highlight the importance of defining clinically meaningful tools to diagnose AMR in heart and lung transplant recipients. The production of post transplant antibodies to the mismatched donor HLA is also linked to failure of transplanted organs. Heart transplant patients develop coronary artery disease also referred to as chronic rejection. A featured abstract presented by Dr. Allison Gareau, Dalhousie University, Halifax, NS, Canada, will highlight the significance of alloantibodies in the process of chronic rejection. In lung transplant recipients, AMR or bronchiolitis obliterans is a chronic rejection process that is immune mediated. Two featured abstracts will discuss exciting new research to diagnose and prevent bronchiolitis obliterans in lung transplant patients. Vibha N. Lama, MD, University of Michigan, will report on the mesenchymal stem cells in the transplanted lung as a predictor of bronchiolitis obliterans. Aric Gregson, MD, University of California Los Angeles, will describe the importance of T regulatory cells in preventing bronchiolitis obliterans in lung transplant patients. The mechanisms underlying transplant vasculopathy are not well understood; however, new research studies indicate an important role for C4d Th17 T-helper cells in promoting this process in heart and lung transplants. Th17 cells produce a cytokine called IL-17, which promotes secretion of inflammatory cytokines and vascular inflammation setting the stage for the progression of transplant vasculopathy. IL-17 producing C4d Th17 cells may serve as novel targets for prevention of heart and lung transplant rejection. About ISHLT: ### Media Contact: Add this page to your favorite Social Bookmarking websites |
