Banff Histopathological Consensus Criteria for Preimplantation Kidney Biopsies

Abstract

The Banff working group on preimplantation biopsy was established to develop consensus criteria (best practice guidelines) for the interpretation of preimplantation kidney biopsies. Digitally scanned slides were used (i) to evaluate interobserver variability of histopathologic findings, comparing frozen sections with formalin‐fixed, paraffin‐embedded tissue of wedge and needle core biopsies, and (ii) to correlate consensus histopathologic findings with graft outcome in a cohort of biopsies from international medical centers. Intraclass correlations (ICCs) and univariable and multivariable statistical analyses were performed. Good to fair reproducibility was observed in semiquantitative scores for percentage of glomerulosclerosis, arterial intimal fibrosis and interstitial fibrosis on frozen wedge biopsies. Evaluation of frozen wedge and core biopsies was comparable for number of glomeruli, but needle biopsies showed worse ICCs for glomerulosclerosis, interstitial fibrosis and tubular atrophy. A consensus evaluation form is provided to help standardize the reporting of histopathologic lesions in donor biopsies. It should be recognized that histologic parameters may not correlate with graft outcome in studies based on organs deemed to be acceptable after careful clinical assessment. Significant limitations remain in the assessment of implantation biopsies.

Digital pathology in nephrology clinical trials, research, and pathology practice

“…Similar studies applying convolutional neural network demonstrated the value of cortical structural changes, such as interstitial fibrosis, in predicting estimated glomerular filtration rate decline [44]. Furthermore, utilizing visual morphologic and computer-aided morphometric protocols to measure fibrosis, novel, and useful information residing in the analysis of the medulla can be retrieved [4 ▪ ]. Overall, these studies point to an imminent adjustment of historical paradigms and parameters for renal biopsy adequacy, measured as number of glomeruli and cortex/medulla ratio.…”

“…While glass slides may fade, break, be lost, and need to be warehoused, high-quality WSI are permanent and occupy ‘virtual’ space. Web-hosted image libraries can be accessed by multiple users, in underresourced locations, and for multiple purposes (e.g., to test different scoring systems simultaneously or consecutively), with abatement of costs with time and improved workflow [2 ▪▪ ,3,4 ▪ ]. …”

“…Validation studies demonstrated that workflow is improved, with general concordance of diagnoses between digital pathology and light microscopy [6,26–28], and with good inter and intrareader concordance for diagnoses and scoring criteria [4 ▪ ,29,30], although some authors reported notable differences in concordance between diagnostic groups [31]. Pathologists recorded mixed experiences about using WSI over glass slides [26,32]…”

“…Novel quantitative digital visual protocols for morphologic profiling of native and transplant kidney biopsies were recently proposed and tested across the globe. [2 ▪▪ ,3,4 ▪ ,9,10 ▪ ,11 ▪ ,38] One example is provided by the NEPTUNE digital pathology protocol for pathology material acquisition and digital annotation, and the NEPTUNE/INTEGRATE scoring system for harmonization of language, comprehensiveness of the descriptor (observational data) used in the analysis, quantification of the parameters observed, and data collection and reporting (Fig. 3) [2 ▪▪ ].…”

“…Virtual microscopy, encompassing telepathology and whole slide imaging (WSI), and digital pathology, a dynamic, image-based environment for the acquisition, management, and interpretation of disease information generated from WSI or other digitized images, are becoming the new standard of practice in the setting of clinical trials [1] and research [2 ▪▪ ,3,4 ▪ ]. Simultaneously, telepathology and WSI are consciously, but progressively, introduced to patient care [5–8].…”