Kidney Week

Abstract: TH-PO1031

Stem-Cell Adjuncts in Kidney Transplantation: A Systematic Review and Meta-Analysis of Randomized Trials

Session Information

• Transplantation: Clinical - Outcomes, Malignancy, and Pathology
  October 22, 2026 | Location: Exhibit Hall A, Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Transplantation

• 2002 Transplantation: Clinical

Authors

• Arslan, Felemez, Istanbul Bakirkoy Dr Sadi Konuk Egitim ve Arastirma Hastanesi, Istanbul, Turkey

Felemez Arslan, MD

• Fatima, Syeda Rubab, Combined Military Hospital Lahore, Lahore, Punjab, Pakistan

Syeda Rubab Fatima, MBBS

• Mehdi, Syed Muhammad Hussain, Rashid Latif Medical College, Lahore, Pakistan

Syed Muhammad Hussain Mehdi, MBBS

• Bayer, Ekin Siar, Istanbul Saglik ve Teknoloji Universitesi, Istanbul, Turkey

Ekin Siar Bayer

• Gunay, Irem Inci, Istanbul Saglik ve Teknoloji Universitesi, Istanbul, Turkey

Irem Inci Gunay

• Silva, Rafaela Pereira, Universidade Estadual do Maranhao, São Luís, MA, Brazil

Rafaela Pereira Silva

• Soto Sanchez, Alfredo Hiram, Hospital Poliplaza Medica, Ciudad Juarez, Chih., Mexico

Alfredo Hiram Soto Sanchez, MD

• Gungor, Burcu, Ege Universitesi, Izmir, Turkey

Burcu Gungor, PhD

• Magal, Abhijith, Kuavery Hospital, Chennai, India

Abhijith Magal, MD, MBBS

Background

Stem cell–based immunomodulation, including mesenchymal stromal cell (MSC) and donor-derived hematopoietic stem cell (HSC) tolerance protocols, may reduce rejection and enable immunosuppression minimization after kidney transplantation, but randomized evidence is small and heterogeneous.

Methods

We searched MEDLINE, Embase, CENTRAL, Scopus, and Web of Science from inception to February 2026 for randomized trials of peri- or post-transplant stem cell therapy versus control immunosuppression in kidney transplant recipients. Two reviewers screened records, extracted data, and assessed risk of bias using Cochrane RoB 2. Random-effects REML meta-analysis with Hartung–Knapp confidence intervals and prediction intervals was performed at the longest follow-up. Effects are risk ratios (RR) or mean differences (MD); MSC versus HSC strategy was prespecified.

Results

Eight randomized trials were included, of which six trials involving 354 kidney transplant recipients contributed quantitative data. Most studies were small open-label trials with high risk of bias or some concerns under RoB-2. Across pooled analyses, stem cell adjunct therapy was not associated with statistically significant differences in biopsy-proven acute rejection (RR 0.74, 95% CI 0.15–3.70; I²=49%), graft loss (RR 1.43, 95% CI 0.25–8.08; I²=0%), all-cause mortality (RR 0.53, 95% CI 0.01–34.36; I²=20%), delayed graft function (RR 0.49, 95% CI 0.04–5.60; I²=34%), or eGFR (MD +5.81 mL/min/1.73m², 95% CI −3.67 to 15.28; I²=0%). Prediction intervals remained wide across outcomes, reflecting substantial clinical and methodological heterogeneity. No significant subgroup difference was observed between MSC- and HSC-based approaches for acute rejection (p=0.39). Sensitivity analyses accounting for overlapping cohorts did not materially alter results.

Conclusion

Current randomized evidence shows no clear benefit or harm of stem cell adjunct therapy in kidney transplantation. Clinically meaningful effects remain possible because trials are small, heterogeneous, and methodologically limited. Larger standardized randomized trials are needed before clinical use can be defined.