Transplant immunology
-
Induction of tolerance, which obviates the need for maintenance immunosuppression following organ transplantation remains elusive. In cardiac transplantation, ongoing immunosuppressive therapy is essential to ensure long-term graft survival. Although drug regimens have substantially improved in recent years, their adverse effects continue to cause significant morbidity and affect quality of life. ⋯ In addition to the conventional clinical parameters which include therapeutic drug monitoring, endomyocardial biopsy and echocardiography, newer techniques for monitoring hold future promise. These include detection of circulating alloantibodies and quantitative measurement of the net state of immunosuppression (Cylex). However, the efficacy of these modalities requires further investigation.
-
Transplant immunology · Apr 2008
ReviewNatural killer cells and lung transplantation, roles in rejection, infection, and tolerance.
Despite improvements in surgical technique, organ preservation, immunosuppression, and management of infection, the long term survival following lung transplantation remains low, mainly due to immune mediated complications such as acute and chronic rejection. Almost all immunosuppressive agents used in the prophylaxis and treatment of rejection following lung transplantation are targets of T cell maturation, function or proliferation, which in theory should cause sufficient disruption of the adaptive immune system to prevent graft rejection. ⋯ More recent evidence suggests that NK cells may play a significant role in immune processes following lung transplantation. This article reviews the literature on the potential function of NK cells in rejection, infection, malignancy and tolerance following lung transplantation.
-
Transplant immunology · Apr 2007
Comparative StudyBacterial superantigen TSST-1 attenuates suppressive efficacy of glucocorticoids and calcineurin inhibitors against blastogenesis of peripheral blood mononuclear cells from patients with chronic renal failure on hemodialysis treatment.
Many cases of patients with chronic renal failure (CRF) on hemodialysis are known to be infected with Staphylococcus aureus (S. aureus) from the sites of blood vessel puncture for hemodialysis and the custody of the vascular access catheter. S. aureus produces superantigens, such as toxic shock syndrome toxin-1 (TSST-1), which may influence the sensitivity of peripheral-blood mononuclear cells (PBMCs) to immunosuppressive drugs after they are received postrenal transplantation. ⋯ These observations raise the possibility that TSST-1 induced by S. aureus infection attenuates the clinical efficacy of glucocorticoids and calcineurin inhibitors in CRF patients after renal transplantation. Furthermore, INF-gamma and IL-4 related pathways appear not to play major roles in the TSST-1-induced attenuation of the drug sensitivities.
-
Transplant immunology · Jan 2003
Genetic modification of cold-preserved renal grafts using HSP70 or bcl-2 HVJ-liposome method.
We tested the hypothesis that the best time for genetic modification is while the cell viability of the graft is reduced for long-term preservation. The hemagglutinating virus of Japan (HVJ)-liposome method, a nonviral gene transfer technique, was used with a luciferase gene to test the efficacy of protein induction under the critical preservation time. Furthermore, we tested this genetic modification with heat shock protein (HSP) 70 or bcl-2 genes to prevent primary nonfunction (PNF) after long-term preservation. ⋯ The HVJ-liposome method effectively induced the foreign gene for kidney grafts even in the cold-preservation solution. Induction of bcl-2 or the HSP70 gene reduced the occurrence of PNF in the rat renal graft. The results suggest that gene transfer not only maintains graft viability, but also graft activation.
-
Almost all identified acute and/or severe immunological reactions towards blood transfusions, reported by surveillance systems such as SHOT (Severe Hazards of Transfusion) in the UK are mediated by allo-antibodies. In contrast, the clinical effects of transfusion-induced cellular immunity are virtually unknown. Although alterations in lymphocyte responses and natural killer cell functions after blood transfusion has been reported in many publications, the relevance of these in vitro assays for in vivo immunity are lacking. ⋯ Since the UK and France introduced a transfusion vigilance system, severe immunological side-effects such as haemolytic reactions, TRALI (acute lung injury), PTP (post-transfusion purpura) and graft vs. host disease are registrated in these countries and their incidence can be estimated based on the national number of transfusions. However, every blood transfusion interferes with the immune system of the recipient. The available evidence of harm from immune responses not leading to severe transfusion reactions will be discussed.