Session Time: 4:30pm-5:30pm
Presentation Time: 4:55pm-5:00pm
*Purpose: I-IFTA in renal allograft Bx has been found to be associated with decreased death-censored graft survival. Moderate to severe i-IFTA (2 or 3) is required for chronic active TCMR diagnosis by current Banff classification, although multiple recent studies have suggested that i-IFTA has no specificity to either TCMR or ABMR. Here we conducted an analysis on i-IFTA’s association with TCMR or ABMR activity in Bx from patients in our center.
*Methods: After excluding Bx with non-rejection causes of inflammation (glomerulonephritis, bacterial or viral infection), 361 Bx from 202 grafts were included and had Banff scores determined. Among them, 131 Bx from 131 unique grafts had definitive rejection diagnoses (52 ABMR, 21 ABMR+TCMR, 23 TCMR) or no rejection (n=35), and their i-IFTA scores were compared. Additionally, 101 pairs of consecutive Bx from 93 grafts were evaluated for possible changes of i-IFTA. Of these, 38 pairs of Bx from 38 grafts showed i-IFTA increasing from 0-1 to 2-3 (Bx intervals all <36 months [12.4±8.9]) and were analyzed for rejection diagnoses. 17 Bx pairs had only ABMR in both Bx (interval: 12.6±8.3 months) and 14 Bx pairs had only TCMR in both Bx (interval: 7.8±6.4 months), each pair from a different graft.
*Results: Among 131 Bx with definitive rejection diagnosis, i-IFTA score was significantly higher in both TCMR and ABMR+TCMR groups vs. ABMR and no rejection groups with no significant difference between the latter 2 groups (Table 1). In the 38 pairs of Bx with increased i-IFTA, significant increase of TCMR activity (p=0.02) in the 2nd Bx was found by paired comparison, while ABMR activity did not change. 14 pairs of ABMR-free TCMR Bx showed high i-IFTA score in the 1st Bx of each pair, and the high score tended to further increase in the 2nd Bx (from 1.9±1.4 to 2.5±0.9, p=0.16), while 17 pairs of TCMR-free ABMR Bx showed minimal i-IFTA in both the 1st and 2nd Bx with no change (from 0.2±0.8 to 0.4±1.0, p=0.47).
|p (vs. ABMR)||0.02||<0.01||0.70|
|p (vs. ABMR+TCMR)||0.56||0.02|
|p (vs. TCMR)||<0.01|
*Conclusions: Significant i-IFTA in Bx appeared to be primarily associated with TCMR, but not ABMR activity, in our patients. The i-IFTA increase in consecutive Bx from the same patients with TCMR, but not ABMR activity, further supports this finding. More study is required to determine if this finding is specific to our patient cohort or more widely applicable.
To cite this abstract in AMA style:Zhang H. Inflammation in Scarred Cortex (i-IFTA) is Significantly Associated with T Cell-mediated Rejection (TCMR), but Not Antibody-mediated Rejection (ABMR), in Renal Allograft Biopsies (Bx) [abstract]. Am J Transplant. 2021; 21 (suppl 3). https://atcmeetingabstracts.com/abstract/inflammation-in-scarred-cortex-i-ifta-is-significantly-associated-with-t-cell-mediated-rejection-tcmr-but-not-antibody-mediated-rejection-abmr-in-renal-allograft-biopsies-bx/. Accessed January 21, 2022.
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