Association of angiotensin II type 1 receptor antibodies with graft histology, function and survival in paediatric renal transplant recipients

Nephrol Dial Transplant. 2018 Jun 1;33(6):1065-1072. doi: 10.1093/ndt/gfy008.

Abstract

Background: We analysed in a carefully phenotyped cohort of paediatric patients the association of serum angiotensin II type 1 receptor antibodies (AT1R-Ab) with specific histological lesions and with graft function and survival in conjunction with overall and complement-binding donor-specific human leucocyte antigen donor-specific antibodies (HLA-DSA).

Methods: Sera of 62 patients at the time of renal graft biopsy for clinical indication >1 year post-transplant were assessed for AT1R-Ab by enzyme-linked immunosorbent assay (ELISA) and for DSA and C1q-fixing DSA by single-antigen bead technology.

Results: Serum AT1R-Ab concentration was significantly higher in antibody-mediated rejection (ABMR) than in T-cell-mediated rejection or control. By receiver operating characteristic (ROC) curve analysis, the optimal AT1R-Ab cut-off value discriminating between patients with features of ABMR and those without was 9.5 U/mL. A total of 6 of 28 patients (21.4%) with ABMR were only positive for AT1R-Ab. Patients with AT1R-Ab and HLA-DSA double positivity had a significantly higher vascular micro-inflammation score than DSA-negative patients. The 5-year graft survival was only 59% in the AT1R-Ab-positive group compared with 87% in the AT1R-Ab-negative group. Patients with AT1R-Ab and HLA-DSA double positivity tended to have a more rapid decline of estimated glomerular filtration rate (eGFR) than patients who were only positive for AT1R-Ab or HLA-DSA. In a multivariate Cox regression model of non-invasive factors, C1q-positive HLA-DSA, eGFR and AT1R-Ab positivity were significantly associated with accelerated graft function decline.

Conclusions: Serum AT1R-Ab positivity in the context of an indication biopsy >1 year post-transplant is associated with the histopathology of ABMR and is an independent non-invasive risk factor for adverse graft outcome.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Antibodies / adverse effects*
  • Antibodies / immunology
  • Child
  • Female
  • Glomerular Filtration Rate
  • Graft Rejection / etiology
  • Graft Rejection / mortality*
  • Graft Rejection / pathology
  • Graft Survival*
  • HLA Antigens / immunology*
  • Humans
  • Kidney Transplantation / adverse effects*
  • Male
  • Receptor, Angiotensin, Type 1 / blood
  • Receptor, Angiotensin, Type 1 / immunology*
  • Retrospective Studies
  • Risk Assessment
  • Risk Factors
  • Survival Rate
  • Tissue Donors
  • Transplant Recipients / statistics & numerical data*

Substances

  • Antibodies
  • HLA Antigens
  • Receptor, Angiotensin, Type 1