The presence of i-IFTA in allograft kidney biopsies is a bad prognostic parameter. However, despite the presence of T-cell infiltrates in these lesions there is reluctance to accept i-IFTA as a criterion of chronic TCMR. Therefore, we compared expression of T-cell genes in TCMR biopsies with or without i-IFTA. Parallel analysis was performed on biopsies with no pathology, acute tubular injury (ATI) and native interstitial nephritis (ISN). 12 renal biopsies were processed using the Pure Link FFPE tissue Total RNA & Ion Ampliseq Trancriptome Human Gene Expression Kits. Differential RNA expression analysis identified upregulation of 5273 genes in TCMR biopsies with and 2894 genes in biopsies without IFTA.(Table 1)24 genes upregulated in i-IFTA have been previously reported in TCMR. 364 genes upregulated in biopsies with native ISN overlap with i-IFTA literature. 33 genes upregulated in biopsies with i-IFTA overlap with genes reported in ATI, and conversely 38 genes upregulated in biopsies ATI have been previously reported in TCMR. In conclusion, i-IFTA biopsies express that are typical of TCMR. Therefore, i-IFTA should be accepted as a criterion of chronic TCMR, provided alternate explanations of fibrosis can be clinically excluded. The presence of similar transcripts in native ISN calls for caution in using molecular testing as a stand-alone modality to diagnose TCMR.

Table 1. Changes in Gene Expression in TCMR Biopsies with or without Fibrosis Compared to Controls with no Pathology (n=6)

CITATION INFORMATION: Lyu Z, Pang L, Zeng G, Huang Y, Randhawa P. Expression of T-Cell Mediated Rejection (TCMR) Associated Genes in Native and Renal Allograft Renal Biopsies with Inflamed Scars (i-IFTA). Am J Transplant. 2017;17 (suppl 3).

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