• Childhood Kidney Diseases
• /
• v.12 no.1
• /
• pp.23-29
• /
• 2008

Kidney allograft transplantation is the most effective method of renal replacement for end stage renal disease patients. Still, it is another kind of 'disease', requiring immunosuppression to keep the allograft from rejection(allograft immune reaction). Immune system of the allograft recipient recognizes the graft as a 'pathogen (foreign or danger)', and the allograft-recognizing commanderin-chief of adaptive immune system, T cell, recruits all the components of immune system for attacking the graft. Proper activation and proliferation of T cell require signals from recognizing proper epitope(processed antigen by antigen presenting cell) via T cell receptor, costimulatory stimuli, and cytokines(IL-2). Thus, most of the immunosuppressive agents suppress the process of T cell activation and proliferation.

• Clinical and Experimental Pediatrics
• /
• v.64 no.2
• /
• pp.49-59
• /
• 2021

Since the initial International Society of Heart Lung Transplantation registry was published in 1982, the number of pediatric heart transplantations has increased markedly, reaching a steady state of 500-550 transplantation annually and occupying up to 10% of total heart transplantations. Heart transplantation is considered an established therapeutic option for patients with end-stage heart disease. The long-term outcomes of pediatric heart transplantations were comparable to those of adults. Issues affecting long-term outcomes include acute cellular rejection, antibody-mediated rejection, cardiac allograft vasculopathy, infection, prolonged renal dysfunction, and malignancies such as posttransplant lymphoproliferative disorder. This article focuses on medical issues before pediatric heart transplantation, according to the Korean Network of Organ Sharing registry and as well as major problems such as graft rejection and cardiac allograft vasculopathy. To reduce graft failure rate and improve long-term outcomes, meticulous monitoring for rejection and medication compliance are also important, especially in adolescents.

• Journal of Veterinary Clinics
• /
• v.22 no.4
• /
• pp.439-443
• /
• 2005

Rejection is one of the life-threatening complications after organ transplantation. An eight-month-old, intact male, mixed breed dog was presented with acute rejection after renal allograft. The heterotopic renal transplantation with bilateral nephrectomy was performed in the dog. The triple drug protocol for immunosuppression was applied for prevention of the acute rejection. Postoperative care was done according to the transplantation protocol of VMTH, Kangwon National University. The dog was euthanized when the serum creatinine concentration exceeded 5 mg/dL followed by tile signs of illness. The transplanted kidney was enlarged. The renal cortex lesions were characterized by necrosis of the renal tubules and the glomeruli. Interstitial lesions were characterized by hemorrhage and severe infiltration of lymphoid cells. Intrarenal arteries showed necrosis of the walls and infiltration of perivascular lymphoid cells. In immunohistochemical (IHC) findings, infiltration of the CD4 and the CD8 positive T lymphocytes was examined. In this case, acute rejection was shown by humoral and cellular immunity on the basis of histopathologic and IHC evaluation.

• Korean Journal of Transplantation
• /
• v.28 no.3
• /
• pp.113-120
• /
• 2014

Two-signal models are useful in explaining various types of immune responses. In particular, secondary, so-called costimulatory, signals are critically required for the process of T-cell activation, survival, differentiation, and memory formation. Early studies in rodent models showed that targeting T-cell costimulatory pathways elicits immunological tolerance, providing a basis for development of costimulatory therapeutics in allograft rejection. However, as the classic definition of T-cell costimulation continues to evolve, simple blockade of costimulatory pathways has limitations in prevention of allograft rejection. Furthermore, functions of costimulatory molecules are much more diverse than initially anticipated and beyond T cells. In this mini-review, we will discuss CD137-CD137L bidirectional signals as examples showing that two-signals can be applicable to multiple phases of immune responses.

• Childhood Kidney Diseases
• /
• v.11 no.2
• /
• pp.152-160
• /
• 2007

Twenty-six renal allograft biopsies which showed acute rejection and had renal capsule and medulla in the same specimen were selected in order to compare the severity of acute rejection between superficial cortex, deep cortex and medulla. Disregarding the mid cortical region, the superficial cortex was considered as being one-third of the distance from the renal capsule to the medulla and the deep cortex as being that one-third of the cortex which was adjacent to the medulla. Using semiquantitative histologic analysis the following parameters were compared in superficial cortex, deep cortex, and medulla: interstitial inflammation, edema, tubulitis, and acute tubulointerstitial rejection grade. Also, the presence of lymphocyte activation and polymorphonuclear leukocytes was evaluated. Significantly greater histologic changes of acute rejection were found in the deep cortex vs. supeficial cortex for the following parameters: interstitial inflammation(P=0.013), edema (P=0.023) and tubulointerstitial rejection grade(P=0.016). These findings support the view that biopsies in which deep cortex is not included may result in underestimation of the severity of renal allograft rejection.

• Biomolecules & Therapeutics
• /
• v.13 no.2
• /
• pp.65-77
• /
• 2005

Present article reviews about clinical pharmacology of mycophenolic acid (MPA), the active form of mycophenolate mofetil (MMF), as widely used component of immunosuppressive regimens in the organ transplantation field. MMF, used alone or concomitantly with cyclosporine or tacrolimus, has approved in reducing the incidence of acute rejection and has gained widespread use in solid organ such as kidney, heart and liver transplantation. The application of MPA and development of MMF has shown a considerable impact on immunosuppressive therapy for organ transplantation as a new immunosuppressive agent with different mechanism of action from other drugs after early 1990s. In particular aspect, use of MMF, a morpholinoethyl ester of MPA, represented a significant advance in the prevention of organ allograft rejection as well as allograft and patient survival. In considering MMF clinical data, it is important to note that there is a strong correlation between high MPA area under curve(AUC) values and a low probability of acute allograft rejection. Individual trials have shown that MMF is generally well tolerated and revealed that MMF decreased the relative risk of developing chronic allograft rejection compared with azathioprine. Recent clinical investigations suggested that improved effectiveness and tolerability will results from the incorporation of MPA therapeutic drug monitoring into routine clinical practice, providing effective MMF dose individualization in renal and heart transplant patients. Therefore, MMF has a selective immunosuppressive effect with minimal toxicity and has shown to be more effective that other agents as next step of immunosuppressive agents and regimens that deliver effective graft protection and immunosuppression along with a more favorable side effect.

• Journal of Chest Surgery
• /
• v.55 no.4
• /
• pp.338-356
• /
• 2022

Lung transplantation (LT) is now considered as an effective treatment option for end-stage lung diseases that improves the short and long-term survival rates and quality of life. As increasingly many LT procedures are being performed, the medical complications of LT are also increasing in frequency and emerging as a very important issue for transplant clinicians. Although chronic lung allograft dysfunction and infection are major causes of death after LT, many medical complications, several of which result from immunosuppressive treatment, contribute to increased mortality and morbidity. This article reviews the most frequent and important medical complications of LT, accompanied by a review of the literature and studies from South Korea, including lung allograft rejection, infection, and non-allograft organ systemic complications.

• IMMUNE NETWORK
• /
• v.16 no.4
• /
• pp.219-232
• /
• 2016

Production of high affinity antibodies for antigens is a critical component for the immune system to fight off infectious pathogens. However, it could be detrimental to our body when the antigens that B cells recognize are of self-origin. Follicular helper T, or Tfh, cells are required for the generation of germinal center reactions, where high affinity antibody-producing B cells and memory B cells predominantly develop. As such, Tfh cells are considered as targets to prevent B cells from producing high affinity antibodies against self-antigens, when high affinity autoantibodies are responsible for immunopathologies in autoimmune disorders. This review article provides an overview of current understanding of Tfh cells and discusses it in the context of animal models of autoimmune diseases and allograft rejections for generation of novel therapeutic interventions.

• Korean Journal of Radiology
• /
• v.21 no.8
• /
• pp.1024-1025
• /
• 2020

• Journal of Chest Surgery
• /
• v.42 no.2
• /
• pp.135-140
• /
• 2009

Background: Chronic rejection after a cardiac allograft usually occurs about six months after the operation. Vasculopathy due to chronic rejection causes atherosclerosis in the coronary artery of the transplanted heart and then this causes myocardial injury. We intended to discover and document those findings that occur in a transplanted ascending aorta. Material and Method: In rats weighting $200{\sim}300gm$ (Spraque-Dawley rat), we carried out heterotopic heart allo-transplantation with the modified Ono-Lindsey method and then the rats were administrated cyclosporine (10mg/kg/day). After three months survival, we acquired biopsy materials from the native ascending aorta and the allo-transplanted ascending aorta and we compared them. We classified each severity of 1) intimal thickening, 2) medial hyperplasia, 3) medial calcification, 4) medial inflammation and 5) chondroid metaplasia, which are specific biopsy findings for chronic rejection after a cardiac allograft. Each severity was classified, according to the opinion of one pathologist, in the native ascending aorta biopsies (n=9) and the allo-transplanted ascending aorta biopsies (n=13). The data of the control group and the study group were statistically analyzed with using the Mann-Whitney test (SPSS version 12.0 window). Result: The important changes of the allo-transplanted aorta were intimal thickening (p<0.0001), medial calcification (p=0.045), medial inflammation (p<0.0001) and chondroid metaplasia (p=0.045), but not medial hyperplasia (p=0.36). Conclusion: Cardiac allograft vasculopathy was seen in the transplanted ascending aorta, the same as was seen in the coronary artery, after allograft cardiac transplantation. We have reached the conclusion that chronic rejection also progresses in the aorta.