Kidney Week

Abstract: TH-OR064

Plasma Exchange for the Treatment of Light Chain Cast Nephropathy: A Multicenter Study

Session Information

• Onconephrology: Updates, Therapies, and Mechanisms
  November 06, 2025 | Location: Room 371A, Convention Center
  Abstract Time: 04:30 PM - 04:40 PM

Category: Onconephrology

• 1700 Onconephrology

Authors

• Chewcharat, Api, Brigham and Women's Hospital, Boston, Massachusetts, United States

Api Chewcharat, MD, MPH

• Shincovich, Christina I, Massachusetts General Hospital Department of Medicine, Boston, Massachusetts, United States

Christina I Shincovich, MD

• Kim, Raphael, Harvard T H Chan School of Public Health, Boston, Massachusetts, United States

Raphael Kim, MS

• McGee, Emma E, Harvard T H Chan School of Public Health, Boston, Massachusetts, United States

Emma E McGee, MSc, PhD

• Peterkin, Alexa Caroline, Brigham and Women's Hospital, Boston, Massachusetts, United States

Alexa Caroline Peterkin

• Pirovano, Marta, Brigham and Women's Hospital, Boston, Massachusetts, United States

Marta Pirovano, MD

• Wells, Sophia L., Brigham and Women's Hospital, Boston, Massachusetts, United States

Sophia L. Wells

• Chowdhury, Raad Bin Zakir, Brigham and Women's Hospital, Boston, Massachusetts, United States

Raad Bin Zakir Chowdhury, MD, FASN

• Yee, Andrew J, Massachusetts General Hospital, Boston, Massachusetts, United States

Andrew J Yee, MD

• Leung, Nelson, Mayo Clinic Minnesota, Rochester, Minnesota, United States

Nelson Leung, MD

• Gupta, Shruti, Brigham and Women's Hospital, Boston, Massachusetts, United States

Shruti Gupta, MD, MPH

Background

The use of plasma exchange (PLEX) for myeloma light chain cast nephropathy (LCCN) is controversial. Three randomized controlled trials failed to show a survival benefit or higher rates of renal recovery; however, these were small, and conducted prior to the advent of highly-effective clone-directed therapies. Since then, several uncontrolled observational studies have suggested PLEX is associated with a higher likelihood of kidney recovery. Given this conflicting data, there is significant interhospital variation in the use of PLEX, and ongoing uncertainty about its utility in LCCN.

Methods

We used a target trial emulation (TTE) framework to examine the efficacy of PLEX in the 30 days following LCCN on renal recovery among patients treated at 25 cancer centers across the US from 2010-2024. Renal recovery was defined as alive, not on dialysis, and with a decline of at least one stage of AKI severity at 90 days following LCCN diagnosis. We used inverse probability treatment weighting to adjust for demographics, comorbidities receipt of chemotherapy, baseline laboratory values, date of LCCN, and concomitant nephrotoxic medications.

Results

Of 500 patients included in the TTE, 144 received PLEX within 30 days of LCCN and 356 did not (96% received chemotherapy in the 60 days around LCCN). Of these, 74 (51.4%) had renal recovery at 90 days as compared to 191 (54.0%) in the control group. There was no difference in renal recovery between PLEX vs. non-PLEX-treated patients (OR = 0.66 [95% CI, 0.088-4.68]) (Figure). In a subgroup analysis, there was a trend towards improvement among patients with newly-diagnosed multiple myeloma-associated LCCN (OR = 1.29 [95% CI, 0.21-7.95]) compared to relapsed LCCN (OR = 0.29 [95% CI, 0.037-2.31]); however, there was no difference based on sex, AKI stage, or biopsy-proven vs. clinically diagnosed LCCN.

Conclusion

Our results suggest PLEX is not associated with renal recovery; however, despite the rigorous TTE framework, residual confounding cannot be excluded.

Funding

• Commercial Support – Janssen

Digital Object Identifier (DOI)

• doi: 10.1681/ASN.20254jkwxd2z