Molecular assessment of kidney allografts: are we closer to a daily routine?

Abstract

Kidney allograft pathology assessment has been traditionally based on clinical and histological criteria. Despite improvements in Banff histological classification, the diagnostics in particular cases is problematic reflecting a complex pathogenesis of graft injuries. With the advent of molecular techniques, polymerase-chain reaction, oligo- and microarray technologies allowed to study molecular phenotypes of graft injuries, especially acute and chronic rejections. Moreover, development of the molecular microscope diagnostic system (MMDx) to assess kidney graft biopsies represents the first clinical application of a microarray-based method in transplantation. Whether MMDx may replace conventional pathology is the subject of ongoing research, however this platform is particularly useful in complex histological findings and may help clinicians to guide the therapy.

Chronic Active T-Cell Mediated Kidney Rejection as a Clinically Significant Type of Allograft Loss?

“…Clinical and histological criteria, used so far in aim to assess kidney allografts, are not sufficient in reflecting a complex pathogenesis of graft failure. Their greatest limitations are the descriptive and semi-quantitative character of diagnostic assessments, which yield in lack of knowledge about the actual patomechanisms behind kidney graft rejection [ 7 ]. The answer to this issue is the implementation of molecular techniques into a diagnostic approach, hence this topic was one of the main themes during the XV Banff Conference held in September 2019.…”

Discrepancy Analysis between Histology and Molecular Diagnoses in Kidney Allograft Biopsies: A Single-Center Experience

“…Although histopathology with the Banff classification system remains the gold standard approach for diagnosing T-cell-mediated rejection (TCMR is characterized by interstitial and epithelial infiltration of T-cells and macrophages in the allograft kidney) and antibody-mediated rejection (ABMR) in kidney allograft biopsies [ 2 , 3 ], there are limitations to this strategy: there are currently no external standards available for validation of the Banff criteria, and the scoring is considered semiquantitative with less accuracy and more inter and intra-observer variability [ 4 ]. Hence, the accuracy and reproducibility of histology have been criticized when compared with molecular diagnosis [ 5 , 6 , 7 ].…”