Kidney Week

Abstract: TH-PO1030

Ten-Year Follow-Up of a Phase 1 Trial of Donor-Derived Modified Immune Cell Infusion in Kidney Transplantation

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

• Schaier, Matthias, Medizinische Klinik X, Medizinische Fakultät, Ruprecht Karls-Universität Heidelberg, Heidelberg, Germany

Matthias Schaier, MD, MBA

• Mahler, Christoph Friedrich, Medizinische Klinik X, Medizinische Fakultät, Ruprecht Karls-Universität Heidelberg, Heidelberg, Germany

Christoph Friedrich Mahler, DrMed

• Sommerer, Claudia, Medizinische Klinik X, Medizinische Fakultät, Ruprecht Karls-Universität Heidelberg, Heidelberg, Germany

Claudia Sommerer, MD, MSc

• Kälble, Florian, Medizinische Klinik X, Medizinische Fakultät, Ruprecht Karls-Universität Heidelberg, Heidelberg, Germany

Florian Kälble

• Mueller-Tidow, Carsten, Klinik für Hämatologie, Onkologie, Rheumatologie Medizinische Fakultät, Ruprecht Karls-Universität Heidelberg, Heidelberg, Germany

Carsten Mueller-Tidow, MD

• Zeier, Martin G., Medizinische Klinik X, Medizinische Fakultät, Ruprecht Karls-Universität Heidelberg, Heidelberg, Germany

Martin G. Zeier, MD, FASN

• Weinmann-Menke, Julia, Medizinische Klinik X, Medizinische Fakultät, Ruprecht Karls-Universität Heidelberg, Heidelberg, Germany

Julia Weinmann-Menke, MD

• Schmitt, Michael, Klinik für Hämatologie, Onkologie, Rheumatologie Medizinische Fakultät, Ruprecht Karls-Universität Heidelberg, Heidelberg, Germany

Michael Schmitt, MD, MBA

• Schmitt, Anita, Klinik für Hämatologie, Onkologie, Rheumatologie Medizinische Fakultät, Ruprecht Karls-Universität Heidelberg, Heidelberg, Germany

Anita Schmitt, DrMed

• Morath, Christian, Department of Nephrology and Hypertension, Klinikum Nuremberg, Paracelsus Medical University, Nuremberg, Germany

Christian Morath, MD

Group or Team Name

• TOL I Trial

Background

Administration of modified immune cells (MIC) prior to kidney transplantation has previously been shown to induce donor-specific immunosuppression and a marked expansion of regulatory B lymphocytes. We aimed to determine how this approach influenced the long-term clinical course of treated recipients.

Methods

Ten patients from a phase I clinical trial who received MIC infusions before kidney transplantation were retrospectively compared with 15 matched standard-risk recipients. Follow-up extended to ten years after surgery of the first patient.

Results

The ten MIC recipients showed an excellent clinical course, with stable graft function, no persistent donor-specific HLA antibodies (DSA), no acute rejection episodes, and no opportunistic infections. By contrast, the retrospectively matched control group receiving standard immunosuppression had a higher rate of persistent DSA (5/15 [33%] vs. 0/10 [0%]; log-rank P = 0.046) and more opportunistic infections (10/15 [67%] vs. 0/10 [0%]; log-rank P = 0.0016). Post-transplant malignancies (predominantly non-melanoma skin cancers) occurred in 3/10 (30%) MIC and 3/15 (20%) control patients (Fisher's exact P = 0.65). Both patient death (0 vs. 2) and graft loss (0 vs. 1) were more frequent in the control group.

Conclusion

MIC infusion combined with reduced conventional immunosuppression was associated with preserved graft function over ten years of follow-up, the absence of sustained DSA, and the absence of opportunistic infections. MIC therapy may therefore contribute to long-term graft protection while mitigating the burden of standard immunosuppression. A phase 2 trial with prospective controls is currently ongoing to validate these findings.