移植技術と研究

Renal transplants have been performed in US since 1954. Survival rates have improved with new techniques and immunosuppressants. The 5 year survival rate of cadaveric and living related is 66% and 78% respectively. Renal transplant offers a cost effective and better quality of life. Since 2001 the number of live kidney donors has surpassed cadaveric donors in United States. As a society we need to encourage organ donation via education and outreach programs.

Interstitial fibrosis/tubular atrophy (IF/TA) is, like its predecessor of Chronic Allograft Nephropathy (CAN), a purely descriptive designation depicting the morphological appearances of Chronic Sclerosing lesions observed on renal allograft biopsies in a variety of clinical settings. The term was introduced by the Banff classification in its 2005 meeting as a replacement for the then popular and often misunderstood category 5 of the Banff classification, i.e., the CAN. The aim was to encourage the transplant pathologists to look for and identify the specific causes of late allograft dysfunction on renal allograft biopsies and not just simply dump all the chronic transplant lesions into the paper wastebasket category of CAN. This editorial explores the rationale behind this change and whether the objectives stipulated have been achieved in real practice. We are of the view that the time has arrived to revisit this change of category and its impact on clinical practice in a systematic manner perhaps by one of the Banff working groups.

As a clinical practice, transplantation is a strategy for overcoming disease that could not be readily curable by any existing therapies. The scarcity of the organ number for transplantation in the continuously growing population makes the overall picture critical for meeting the requirement. The prevention of organ rejection, which is caused by the destruction of transplanted tissue by the tissue recipient’s (host) immune system, is mainly focused in routine application. The immunosuppressive drugs provide some benefits against organ rejection, but the immune system with its factors is still a major obstacle in successful transplantation.

It has been long time before a new medicine introduced to the forefront of immunosuppressant therapies. It has come after long extended studies, enrolling hundreds of patients, from different countries, in the phase III of the widely known BENEFIT, and BENEFIT-EXT trials. It sounds like a new hope for the transplantation community, which is still striving to overcome the hurdles of the older regimens of immunosuppressant’s, with its critical side effects, in particular the nonspecificity of the immunosuppression with the consequent issues of the opportunistic infections, the lymphoproliferative and the neoplastic complications. And the other common nonspecific complications like hypertension, diabetes, and the hyperlipidemia with its subsequent mounting cardiovascular mortality and morbidity (the most common cause of mortality in transplant recipients). And most importantly,the ever challenging chronic allograft nephropathy which is partly attributed to the direct Calcineurin inhibitors (CNI) toxicity.