The clinical and pathological significance of borderline T cell-mediated rejection

Am J Transplant. 2019 May;19(5):1452-1463. doi: 10.1111/ajt.15197. Epub 2019 Jan 22.


The pathological diagnosis of borderline rejection (BL-R) denotes possible T cell-mediated rejection (TCMR), but its clinical significance is uncertain. This single-center, cross-sectional cohort study compared the functional and histological outcomes of consecutive BL-R diagnoses (n = 146) against normal controls (n = 826) and acute TCMR (n = 55) from 551 renal transplant recipients. BL-R was associated with the following: contemporaneous renal dysfunction, acute tubular necrosis, and chronic tubular atrophy (P < .001); progressive tubular injury with fibrosis by longitudinal sequential histology (45.3% at 1 year); increased subsequent acute rejection (39.4%), allograft failure (P < .001), and patient mortality (P = .007). BL-R detected by biopsy indicated for impaired function was followed by suboptimal functional recovery (46.3%), persistent inflammation (27.2%), and acute rejection episodes (50.0%) despite antirejection treatment in 83.3%. By 1 year after BL-R, the incidence of new-onset microvascular inflammation (9.3%), C4d staining (22.3%), transplant glomerulopathy (13.3%), and de novo donor-specific antibodies (31.5%) exceeded normal controls (P < .05-.001). BL-R inflammation in protocol biopsy persisted in 28.0% and progressed to acute rejection in 32.6%; however, it resolved in 61.6% of the untreated cases. In summary, BL-R is a heterogeneous diagnostic grouping, ranging from mild inconsequential inflammation to clinically significant TCMR, which is capable of immune-mediated tubular injury resulting in inferior functional, immunological, and histological consequences.

Keywords: biopsy; classification systems: Banff classification; clinical decision-making; clinical research/practice; kidney transplantation/nephrology; pathology/histopathology; rejection: T cell-mediated (TCMR).

Publication types

  • Clinical Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Complement C4b / immunology
  • Female
  • Follow-Up Studies
  • Glomerular Filtration Rate
  • Graft Rejection / etiology
  • Graft Rejection / pathology*
  • Graft Survival / immunology*
  • Humans
  • Isoantibodies / immunology*
  • Kidney Failure, Chronic / pathology
  • Kidney Failure, Chronic / surgery*
  • Kidney Function Tests
  • Kidney Transplantation / adverse effects*
  • Male
  • Middle Aged
  • Postoperative Complications*
  • Prognosis
  • Retrospective Studies
  • Risk Factors
  • T-Lymphocytes / immunology*
  • Tissue Donors
  • Transplant Recipients
  • Transplantation, Homologous


  • Isoantibodies
  • Complement C4b