Detecting antibody-mediated damage in ABO incompatible (ABOi) renal transplants has been hampered by the lack of usefulness of C4d staining. We assessed the relevance of the microcirculation inflammation (MI) score, defined by combining glomerulitis (g) and peritubular capillaritis (ptc), in this population.
The first biopsy taken ≥1 year after ABOi transplantation was classified according to Banff 09 (n=39).
Data were analyzed using clinical information on donor, recipient and post-transplantation variables. Median follow-up was 4.2 (IQR 3.0-5.4) years. Median time to biopsy was 16.7 (IQR 14.4-34.1) months. Clinical characteristics comparing MI0 (n=26) and MI≥1 (n=13) were analyzed with binary logistic regression, either univariate or forced-entry multivariate (including all parameters with p≤0.150). The Kaplan-Meier product limit method was used to estimate time to transplant glomerulopathy (TG) and renal graft failure, with log-rank test to detect differences between the two groups.
On univariate analysis the MI+ and MI- groups differed significantly for donor-specific antibodies (DSA) and incidence of TG development, both were associated with a MI+ score.
In multivariable analysis, donor age, DSA, TG development and death-censored graft survival were entered and only DSA was associated with MI+ (OR 5.7 [95% CI 1.03-31]). Survival estimates show a trend to more development of TG (p=0.091) in patients with an MI+ score, with TG free survival at 3-years post-biopsy in 91% (MI-) vs 66% (MI+). No significant difference could be found in graft survival estimates between the MI groups, with 3-year graft survival rates from biopsy of 94% (MI-) and 71% (MI+) (p=0.162).
MI only correlated with the presence of DSA (both pre and post-formed antibodies). From ABO compatible studies we know that in sensitized and de novo DSA renal transplant patients the MI score associates with graft failure. Unfortunately, due to the small sample size, medium term follow-up and low incidence of MI no correlation for MI with outcome could be found.
To cite this abstract in AMA style:Kort Hde, Charif R, Brookes P, Kanigicherla D, Santos-Nunez E, McLean A, Taube D, Cook H, Galliford J, Roufosse C. Microcirculation Injury Associates with Donor-Specific Anti-HLA Antibodies in ABO Incompatible Renal Transplant Patients [abstract]. Am J Transplant. 2013; 13 (suppl 5). https://atcmeetingabstracts.com/abstract/microcirculation-injury-associates-with-donor-specific-anti-hla-antibodies-in-abo-incompatible-renal-transplant-patients/. Accessed July 31, 2021.
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