Korean J Transplant.  2022 Nov;36(Supple 1):S264. 10.4285/ATW2022.F-4046.

Medullary histology may help to predict Banff scores in allograft kidneys

• Lim BJ
• Jung M

• KMID: 2535491
• DOI: http://doi.org/10.4285/ATW2022.F-4046

Abstract

Background
Most of the current Banff classification parameters for renal allograft are obtained from the cortex. For example, the peritubular capillaritis score is obtained only in cortical capillaries, but their medullary counterpart (vasa recta) is not the object of scoring. In this regard, renal allograft biopsies dominantly composed of the medulla are unsuitable for diagnosing rejection. We compared the cortical components' scores and their medullary counterparts to evaluate whether the medullary scores may contribute to the diagnosis of rejection in medulla-dominant allograft biopsies.
Methods
We collected 50 cases of allograft kidney biopsies that contain both cortex and medulla. Interstitial inflammation, total inflammation, tubulitis, peritubular capillaritis, interstitial fibrosis, tubular atrophy, interstitial inflammation in the area of intersti- tial fibrosis and tubular atrophy (IFTA), and tubulitis in the area of IFTA were scored according to the current Banff classification. Medullary lesions were scored similarly. The correlation of each medullary score with cortical Banff scores was evaluated by the Spearman test.
Results
The medullary scores of tubulitis, interstitial inflammation, total inflammation, tubular atrophy, interstitial fibrosis, inflammation and tubulitis in the area of IFTA, and peritubular capillaritis were significantly correlated with their cortical counterparts. In addition, the medullary peritubular capillaritis score correlated with the glomerular basement membrane double contour score and intimal arteritis score of the cortex.
Conclusions
Some medullary histologic findings are significantly correlated with Banff classification scores. These results may help pathologists to suggest the diagnosis of rejection in medulla-dominant allograft biopsies.