Hara Shigeo
Department of Diagnostic Pathology, Kobe University Graduate School of Medicine, Kobe, Japan.
Nephrology (Carlton). 2018 Jul;23 Suppl 2:45-51. doi: 10.1111/nep.13283.
The Banff histopathology classification system is the gold standard for assessing the causes of kidney allograft dysfunction triggered by antibody-mediated and T-cell-mediated immune reactions, thereby providing mechanistic insight and guiding therapeutic decisions. The original Banff classification (1993) consisted of four histological categories representing cell-mediated rejection: interstitial inflammation (i), tubulitis (t), endoarteritis (v), and transplant glomerulitis (g). The revised Banff 2007 classification added total inflammation score (ti) from both scarred and unscarred areas based on evolving interpretations of interstitial infiltrates. Further reappraisal of cell-mediated interstitial inflammation led to the introduction of a new inflammation score specific for areas of interstitial fibrosis and tubular atrophy, termed i-IF/TA, in the Banff 2015 scheme, establishment of a new Banff working group on T-cell-mediated rejection (TCMR), and revised criteria of chronic active TCMR in Banff 2017 classification. These Banff scheme updates reflect the general recognition that chronic interstitial inflammation is a common denominator of poor kidney allograft outcome. However, revised theories on the pathogenic importance of interstitial infiltrates have created difficulties in interpretation of chronic tubulointerstitial inflammation, as there are currently no histological criteria to discriminate immune-mediated tissue injury from 'non-specific' injury. Evolving theories on vascular lesions, both active and chronic, have also complicated histological assessment by obscuring the distinction between antibody-mediated and T-cell-mediated tissue injury. This review provides an overview of recent ideas on interstitial inflammation and vascular lesions based on emerging concepts of T-cell-mediated rejection.
班夫组织病理学分类系统是评估由抗体介导和T细胞介导的免疫反应引发的肾移植功能障碍原因的金标准，从而提供机制性见解并指导治疗决策。最初的班夫分类（1993年）由代表细胞介导排斥反应的四个组织学类别组成：间质炎症（i）、肾小管炎（t）、动脉内膜炎（v）和移植性肾小球炎（g）。2007年修订的班夫分类根据对间质浸润不断演变的解释，增加了来自瘢痕和非瘢痕区域的总炎症评分（ti）。对细胞介导的间质炎症的进一步重新评估导致在2015年班夫方案中引入了一种针对间质纤维化和肾小管萎缩区域的新炎症评分，称为i-IF/TA，成立了一个关于T细胞介导排斥反应（TCMR）的新班夫工作组，并在2017年班夫分类中修订了慢性活动性TCMR的标准。这些班夫方案的更新反映了人们普遍认识到慢性间质炎症是肾移植不良结局的一个共同特征。然而，关于间质浸润的致病重要性的修订理论在解释慢性肾小管间质炎症方面造成了困难，因为目前尚无组织学标准来区分免疫介导的组织损伤与“非特异性”损伤。关于活动性和慢性血管病变的不断演变的理论也因模糊了抗体介导和T细胞介导的组织损伤之间的区别而使组织学评估变得复杂。本综述基于T细胞介导排斥反应的新出现概念，概述了关于间质炎症和血管病变的最新观点。
