Kidney Week

Abstract: SA-PO0812

Kidney Response to CD19+ Chimeric Antigen Receptor (CAR)-T Cell Treatment of Refractory Systemic Lupus Erythematosus

Session Information

• Glomerular Diseases: Management, Evolving Strategies, and Practice-Changing Advances
  October 24, 2026 | Location: Exhibit Hall A, Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Glomerular Diseases

• 1402 Glomerular Diseases: Clinical, Outcomes, and Therapeutics

Authors

• Kurzhagen, Johanna T., Department of Internal Medicine 4, Nephrology and Hypertensiology, Friedrich-Alexander-University Erlangen-Nürnberg (FAU) and Universitätsklinikum Erlangen, Erlangen, Bavaria, Germany

Johanna T. Kurzhagen, MD

• Iwata, Futoshi, Department of Internal Medicine 3, Rheumatology and Immunology, Friedrich-Alexander-University Erlangen-Nürnberg (FAU) and Universitätsklinikum Erlangen, Erlangen, Bavaria, Germany

Futoshi Iwata, MD

• Laqua, William, Department of Internal Medicine 4, Nephrology and Hypertensiology, Friedrich-Alexander-University Erlangen-Nürnberg (FAU) and Universitätsklinikum Erlangen, Erlangen, Bavaria, Germany

William Laqua, MD

• Hagen, Melanie, Department of Internal Medicine 3, Rheumatology and Immunology, Friedrich-Alexander-University Erlangen-Nürnberg (FAU) and Universitätsklinikum Erlangen, Erlangen, Bavaria, Germany

Melanie Hagen, MD

• Wirsching, Andreas, Department of Internal Medicine 3, Rheumatology and Immunology, Friedrich-Alexander-University Erlangen-Nürnberg (FAU) and Universitätsklinikum Erlangen, Erlangen, Bavaria, Germany

Andreas Wirsching, MD

• Opgenoorth, Mirian, Department of Internal Medicine 4, Nephrology and Hypertensiology, Friedrich-Alexander-University Erlangen-Nürnberg (FAU) and Universitätsklinikum Erlangen, Erlangen, Bavaria, Germany

Mirian Opgenoorth, MD

• Eckstein, Markus, Department of Pathology, Friedrich-Alexander-University Erlangen-Nürnberg (FAU) and Universitätsklinikum Erlangen, Erlangen, Bavaria, Germany

Markus Eckstein, MD

• Amann, Kerstin U., Department of Nephropathology, Friedrich-Alexander-University Erlangen-Nürnberg (FAU) and Universitätsklinikum Erlangen, Erlangen, Bavaria, Germany

Kerstin U. Amann, MD

• Daniel, Christoph, Department of Nephropathology, Friedrich-Alexander-University Erlangen-Nürnberg (FAU) and Universitätsklinikum Erlangen, Erlangen, Bavaria, Germany

Christoph Daniel, PhD

• Schett, Georg, Department of Internal Medicine 3, Rheumatology and Immunology, Friedrich-Alexander-University Erlangen-Nürnberg (FAU) and Universitätsklinikum Erlangen, Erlangen, Bavaria, Germany

Georg Schett, MD, PhD

• Grieshaber-Bouyer, Ricardo, Department of Internal Medicine 3, Rheumatology and Immunology, Friedrich-Alexander-University Erlangen-Nürnberg (FAU) and Universitätsklinikum Erlangen, Erlangen, Bavaria, Germany

Ricardo Grieshaber-Bouyer, MD, PhD

• Schiffer, Mario, Department of Internal Medicine 4, Nephrology and Hypertensiology, Friedrich-Alexander-University Erlangen-Nürnberg (FAU) and Universitätsklinikum Erlangen, Erlangen, Bavaria, Germany

Mario Schiffer, MD, MBA

Background

CD19-directed CAR-T cell therapy is an emerging treatment strategy for refractory systemic lupus erythematosus (SLE), including lupus nephritis (LN). Early clinical studies with CAR T-cells have demonstrated complete renal response accompanied by deep B cell depletion in the majority of SLE patients. However, in selected patients with LN, residual proteinuria is found after CAR T-cell treatment.

Methods

To define the nature of residual proteinuria, we analyzed paired kidney biopsies in LN patients before and after autologous CD19+ CAR-T cell therapy. Histopathological findings and clinical outcomes were analyzed. In addition, high-resolution spatial transcriptomics will be performed to investigate intrarenal immune niches, stromal injury and repair programs, and compartment-specific pathology.

Results

Three LN patients showed residual proteinuria after autologous CD19-CAR-T cell therapy including normal eGFR. All patients were drug-free and showed no signs of SLE activity. Patient 1 had Class I LN in the baseline biopsy and showed podocyte damage comparable to minimal-change-glomerulopathy in the follow-up biopsy. Patients 2 and 3 showed Class IV GN in the baseline biopsies and a damage-associated pattern resembling Class V GN and interstitial fibrotic lesions without activity in the follow-up biopsy.

Conclusion

These findings highlight the renal responses following autologous CD19-directed CAR-T cell therapy. Repeat kidney biopsy remains the essential gold-standard for assessing residual renal disease activity and histopathological changes despite clinical response after CAR-T cell treatment. Supportive proteinuria management may be required in these patients.

Authors JTK and FI contributed equally as co-first authors.
Authors MS and RGB contributed equally as co-senior authors.

Funding

• Government Support – Non-U.S.