Microcirculation Inflammation in Early Surveillance Renal Biopsy in Sensitized Patients Did Not Correlate With Graft Outcome

P. Souza,¹ D. Machado,¹ D. David,¹ G. Bezerra,¹ F. Jota de Paula,¹ H. Rodriges,² W. Nahas,¹ E. David Neto,¹ M. Castro.¹

¹Renal Transplant Unit, HC - FMUSP, S Paulo, SP, Brazil
²Lab de HLA, InCor, S Paulo, SP, Brazil.

Meeting: 2015 American Transplant Congress

Abstract number: A100

Keywords: Alloantibodies, Graft function, Kidney transplantation, Microcirculation

Session Information

Session Name: Poster Session A: Kidney Antibody Mediated Rejection

Session Type: Poster Session

Date: Saturday, May 2, 2015

Session Time: 5:30pm-7:30pm

Presentation Time: 5:30pm-7:30pm

Location: Exhibit Hall E

Introduction: Microcirculation inflammation (MI) at 3-month renal biopsies and preformed donor-specific antibodies (DSA) are considered predictors of bad outcome in sensitized patients. Earlier biopsies and immunological data have not been evaluated in this population yet. The aim of this study was to identify the impact of renal histology, MI, DSA presence and C4d scores on long-term allograft function.

Methods: From July/2010 to December/2012, 547 adult renal transplants were performed at our institution, being 126 (23%) in sensitized patients. Eighty-four sensitized patients with PRA ≥ 10% were included in this study. All patients underwent early surveillance biopsy. DSA were evaluated by Luminex and biopsies classified by Banff criteria. Glomerular filtration rate (eGFR) was estimated by MDRD equation.

Results: Patients were 45.8±11.8 years-old, 78.6% were women, 75% had pre-transplant blood transfusion, 78.6% received a kidney from deceased donor, 78.6% were 1st-transplant. Thymoglobulin was used in 93% and all patients were maintained on prednisone, mycophenolate and tacrolimus. At D0, 51.2% of the patients were DSA+ with mean MFI 4240 ± 3735. Early biopsy was performed at a median 8 days post-transplant (range: 3-25 days). Histological finds were acute tubular necrosis (ATN) in 35.7%, antibody-mediated rejection (ABMR) in 31% (17 type I; 8 type II and 1 type III). ATN plus inflammation occurred in 10.7% of the patients. Four patients presented TCMR (4.7 %), 5 (5.9%) with normal allograft and other non-rejection lesions in 5 (5.9%). MI was observed in 28 (33.3%) patients and correlated with C4d score but not with pre-transplant DSA. Glomerulitis was the main frequent MI component and correlated better with C4d. MI presence did not determined a worse 12 and 24-month eGFR (45.8 ± 18.0 vs 50.0 ± 21.0 mL/min at 12-month; 46.7 ± 21.9 vs 52.6 ± 19.0 mL/min at 24-month; p=NS. When evaluating MI presence, MI components, DSA presence and C4d, only C4d was a predictor of eGFR in linear regression. C4d positive 12-month eGFR was 37.3 ± 17.3 vs 54.3 ± 19.0 mL/min (p= 0.001), and 24 month eGFR was 42.3 ± 19.5 vs 55.3 ± 19.0 mL/min (p= 0.015).

Conclusion: Early biopsy microvascular inflammation was associated with C4d deposition but not with pre-transplant DSA. C4d deposition was the only predictor of long-term eGFR in sensitized patients.

To cite this abstract in AMA style:

Souza P, Machado D, David D, Bezerra G, Paula FJotade, Rodriges H, Nahas W, Neto EDavid, Castro M. Microcirculation Inflammation in Early Surveillance Renal Biopsy in Sensitized Patients Did Not Correlate With Graft Outcome [abstract]. Am J Transplant. 2015; 15 (suppl 3). https://atcmeetingabstracts.com/abstract/microcirculation-inflammation-in-early-surveillance-renal-biopsy-in-sensitized-patients-did-not-correlate-with-graft-outcome/. Accessed May 18, 2025.

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