Pathology of T cell-mediated rejection in renal allograft / 器官移植

T cell-mediated rejection (TCMR) is one of the main mechanisms of rejection in organ transplantation, which is also the most common type of acute rejection.Based on Banff classification on allograft pathology (Banff classification) in 2019, TCMR can be divided into acute TCMR (aTCMR) and chronic active TCMR (caTCMR) according to the characteristics of immune lesions.In this article, the basic definition of TCMR, the research progress on TCMR pathology according to Banff classification for renal allograft, and the basic pathological changes and diagnostic grading of TCMR were reviewed, aiming to provide evidence for early identification, diagnosis and treatment of TCMR and prevent the progression of TCMR into caTCMR, thereby guarantying the long-term survival of both the renal allograft and recipient.

Are the current chronic allograft nephropathy grading systems sufficient to predict renal allograft survival?

A major problem in renal transplantation is identifying a grading system that can predict long-term graft survival. The present study determined the extent to which the two existing grading systems (Banff 97 and chronic allograft damage index, CADI) correlate with each other and with graft loss. A total of 161 transplant patient biopsies with chronic allograft nephropathy (CAN) were studied. The samples were coded and evaluated blindly by two pathologists using the two grading systems. Logistic regression analyses were used to evaluate the best predictor index for renal allograft loss. Patients with higher Banff 97 and CADI scores had higher rates of graft loss. Moreover, these measures also correlated with worse renal function and higher proteinuria levels at the time of CAN diagnosis. Logistic regression analyses showed that the use of angiotensin-converting enzyme inhibitor (ACEI), hepatitis C virus (HCV), tubular atrophy, and the use of mycophenolate mofetil (MMF) were associated with graft loss in the CADI, while the use of ACEI, HCV, moderate interstitial fibrosis and tubular atrophy and the use of MMF were associated in the Banff 97 index. Although Banff 97 and CADI analyze different parameters in different renal compartments, only some isolated parameters correlated with graft loss. This suggests that we need to review the CAN grading systems in order to devise a system that includes all parameters able to predict long-term graft survival, including chronic glomerulopathy, glomerular sclerosis, vascular changes, and severity of chronic interstitial fibrosis and tubular atrophy.