• Childhood Kidney Diseases
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• 제12권1호
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• pp.23-29
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• 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
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• 제64권2호
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• pp.49-59
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• 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.

• 한국임상수의학회지
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• 제22권4호
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• pp.439-443
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• 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.

• 대한이식학회지
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• 제28권3호
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• pp.113-120
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• 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
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• 제11권2호
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• pp.152-160
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• 2007

목 적 : 이식신 생검은 이식신 기능 이상의 원인, 거부반응의 정도, 예후 등을 확인하는데 도움이 된다. 그러나 이식신의 조직학적 변화가 신피질에 고르게 분포하지 않는 경우를 흔히 보게 된다. 따라서 본 연구는 이러한 이식신 생검에서의 잠재적인 표본추출의 오류를 평가하기 위하여 시행되었다. 방법 : 569개의 이식신 생검 표본 중에서 Banff criteria에 준하는 급성 거부반응을 보이고 있으며, 신피막부터 수질까지의 전 층을 포함하고 있는 신생검 표본 26개를 조사하였다. Banff criteria를 변형하여 조직의 변화를 간질성 염증(0-3+), 부종(0-3+), 요세관간질염(0-3+)으로 구분하여 급성거부반응의 등급을 표면 피질, 깊은 피질과 피질에 근접한 수질층 각각을 비교하여 조직학적 분석을 시행하였다. 결과 : 간질성 염증(P=0.019), 부종(P=0.023), 요세관 거부등급(P=0.019)에서 깊은 피질에서 표면 피질에 비해 급성 거부반응의 정도가 심하였다. 결론 : 이식신의 급성 거부반응을 진단하기 위하여 신생검을 실시 할 경우 깊은 피질이 포함되지 않으면 급성 거부반응을 과소 평가 할 수 있으므로 주의해야 할 것으로 사료된다.

• Biomolecules & Therapeutics
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• 제13권2호
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• pp.65-77
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• 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
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• 제55권4호
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• pp.338-356
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• 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
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• 제16권4호
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• pp.219-232
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• 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.

• Journal of Chest Surgery
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• 제42권2호
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• pp.135-140
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• 2009

배경: 동종이형의 심장이식 후에 나타나는 만성 거부반응은 수술 후 약 6개월이 지나 나타나며, 이로 인해 이식된 심장의 관상동맥의 동맥 경화 소견과 심장의 손상을 일으키는 혈관병증이 나타나는 바, 대혈관인 대동맥에서도 이러한 소견을 보이는 지를 확인하고자 하였다. 대상 및 방법: $200{\sim}300gm$의 백서(Spraque-Dawley Rat)에서 이소성의 동종이형의 심장이식(heterotopic heart alto-transplantation)을 Ono-Lindsey method로 시행한 후 사이클로스포린(cyclosporin A 10mg/kg/day, 종근당 제공)을 투여하여 3개월 이상 생존한 군에서 동물을 희생시킨 후 자가 상행 대동맥과 이식된 심장의 대동맥에서 각각 조직 절편을 얻어 조직 검사를 시행하여 비교하였다. 자가 상행 대동맥의 조직 검사(N=9, native ascending aorta)와 동종 이형의 이식된 심장의 대동맥(N=13, alto-transplanted aorta)의 조직 검사를 동종이형의 심장이식 후의 만성 거부 반응의 특징적인 조직 검사 소견인 1) 내막 비후(intimal thickening), 2) 중층 비후(medial hyperplasia), 3) 중층 석회화(medial calcification), 4) 중층 염증(medial inflammation), 5) 연골 화생(chondroid metaplasia)에 대하여 한 명의 병리의에 의해 대조군과 이식군에서 각각 심한 정도를 통계처리(Mann-Whitney Test, SPSS version 12.0 Windows)하여 비교하였다. 결과: 중층 비후 외(p=0.36)에 내막 비후(p<0.0001), 중층 석회화(p=0.045), 중층 염증(p<0.0001), 연골 화생(p=0.045)에 있어 이식된 심장의 대동맥에서 의미 있는 변화를 보였다. 결론: 동종 이형의 심장 이식 후에 만성 거부 반응에 의한 혈관병증(cardiac allograft vasculopathy)은 관상 동맥을 침범하여 심근의 손상을 가져오며, 이와 같은 만성 거부 반응에 의한 혈관 병증의 변화는 대혈관인 이식된 대동맥에서도 상기의 결과와 같이 나타나 대동맥에서도 만성적인 거부 반응이 진행되고 있음을 확인할 수 있었다.

• Clinics in Shoulder and Elbow
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• 제19권2호
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• pp.84-89
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• 2016

Background: The purpose of this study was to assess the results of arthroscopic bridging repair using a human dermis allograft in the treatment of massive irreparable rotator cuff tears. Methods: From November 2009 to April 2011, 12 patients underwent arthroscopic bridging repair using a human dermis allograft in the treatment of massive irreparable rotator cuff tears. Patients were followed for an average of 33.9 months. Clinical outcome was evaluated preoperatively and postoperatively using the mean University of California, Los Angeles (UCLA) score and the Korean Shoulder Scoring System (KSS). Magnetic resonance imaging (MRI) was performed postoperatively at an average of 6.5 months. Results: At a mean follow-up of 33.9 months (range, 25 to 42 months), 11 out of 12 patients were satisfied with their procedure. Patients showed significant improvement in their mean modified UCLA score from 15.9 preoperatively to 29.4 postoperatively (p=0.001). The mean KSS score improved from 45.6 preoperatively to 80.5 postoperatively (p=0.002). In MRI studies, 9 out of 12 patients had full incorporation of the graft into the native rotator cuff remnant. To date, there has been no intraoperative or postoperative complication from the graft procedure, such as infection or allograft rejection, in any patient. Conclusions: Arthroscopic bridging repair using a human dermis allograft can be considered as an option in treatment of select cases of massive irreparable rotator cuff tears, resulting in high patient satisfaction.