Document Type
Article
Publication Date
8-2026
Identifier
DOI: 10.1111/ctr.70661; PMCID: PMC13505398
Abstract
BACKGROUND: Calcineurin inhibitors (CNIs) revolutionized kidney transplantation by reducing acute rejection rates. Identical twin kidney transplantation is the only setting in which the allograft is immunologically indistinguishable from self, yet CNI use persists. We characterized CNI utilization across end-stage kidney disease etiologies and examined whether CNI exposure was associated with reduced rejection or improved death-censored graft survival (DCGS).
METHODS: We performed a retrospective cohort study using scientific registry of transplant recipients data (January 2000-August 2025). Among 255 adult identical twin kidney transplant recipients, discharge regimens were categorized by CNI use; Firth penalized Cox regression was the primary method for 10-year DCGS.
RESULTS: Among recipients, 129 (50.6%) received a CNI at discharge with no decline over 25 years and use across every etiology, including glomerulonephritis (53.6%), cystic disease (80.0%), diabetes (51.8%), and hypertension (50.0%), several of which carry no recurrence or immunologic rationale. No biopsy‑proven rejections occurred within the first year. CNI use was not associated with improved DCGS in the full cohort (HR, 1.67; 95% CI, 0.72-4.13; P = 0.234) or the glomerulonephritis subgroup (log-rank P = 0.582).
CONCLUSION: Half of U.S. identical twin kidney transplant recipients receive CNIs at discharge, with no utilization decline over 25 years. This practice is not supported by measurable reductions in rejection or improved graft survival and warrants clinical re-evaluation.
Journal Title
Clinical transplantation
Volume
40
Issue
8
First Page
70661
Last Page
70661
MeSH Keywords
Humans; Kidney Transplantation; Female; Graft Rejection; Retrospective Studies; Graft Survival; Prognosis; Calcineurin Inhibitors; Follow-Up Studies; Male; Kidney Failure, Chronic; Adult; Middle Aged; Glomerular Filtration Rate; Risk Factors; Twins, Monozygotic; Immunosuppressive Agents; Survival Rate; Registries; Kidney Function Tests; Postoperative Complications
PubMed ID
42640087
Keywords
Maintenance immunosuppression; Monozygotic (MZ) twins; acute rejection; calcineurin inhibitors (CNI); death‐censored graft survival (DCGS); glomerulonephritis (GN); identical twin kidney transplantation; living donor; scientific registry of transplant recipients (SRTR)
Recommended Citation
Herrera NS, Wadnerkar S, Cibrik DM. Are We Winning at Twinning? Persistent CNI Use in Identical Kidney Transplants. Clin Transplant. 2026;40(8):e70661. doi:10.1111/ctr.70661
Comments
This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.
Publisher's Link: https://onlinelibrary.wiley.com/doi/10.1111/ctr.70661