Abstract: TH-PO0225
Therapeutic Plasma Exchange and Changes in Calcium, Phosphate, Parathyroid Hormone, and Fibroblast Growth Factor 23
Session Information
- Bone and Mineral Metabolism: Clinical Reports and Practice
November 06, 2025 | Location: Exhibit Hall, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Bone and Mineral Metabolism
- 502 Bone and Mineral Metabolism: Clinical
Authors
- Jin, Sami SeungMi, University of California San Diego, La Jolla, California, United States
- Dugar, Anushree, Sinai Hospital, Baltimore, Maryland, United States
- Hoofnagle, Andrew N., University of Washington, Seattle, Washington, United States
- Sanchez, Amber P., UC San Diego Health, San Diego, California, United States
- Ward, David M., UC San Diego Health, San Diego, California, United States
- Ix, Joachim H., UC San Diego Health, San Diego, California, United States
- Ginsberg, Charles, UC San Diego Health, San Diego, California, United States
Background
Therapeutic plasma exchange (TPE) removes proteins including antibodies and hormones, causing nonspecific alterations of plasma components. While TPE treatment reduces vitamin D metabolites by ~70%, its effects on vitamin D’s hormonal regulators and other metabolites remain unclear.
Methods
We collected blood and effluent samples from 42 patients receiving out-patient TPE between July and September 2020. Plasma and effluent levels of total calcium, phosphate, PTH, and FGF-23 were measured pre-TPE, post-TPE, and at follow-up prior to the subsequent TPE. Paired t-tests evaluated percent changes and recovery relative to baseline.
Results
Study participants had a mean age of 55±16 years, 28 (67%) were female and 32 (76%) were white. TPE acutely reduced total calcium (-9%; 95%CI -11%, -8%), phosphate (-14%; 95%CI -18%, -11%), and FGF-23 (-12%; 95%CI -18%, -6%), while PTH increased by 91% (95%CI 63%, 119%) from baseline to post-TPE (p<0.001 for all). By follow-up (median 4 days), most metabolites returned to baseline. However, ~25% of patients continued to experience asymptomatic hypocalcemia and increased PTH concentrations at follow-up, despite continuous IV calcium gluconate infusions during all TPE treatments.
Conclusion
TPE induced significant acute changes in mineral metabolism, with prolonged hypocalcemia despite supplementation and physiologic compensation. These findings suggest potential long-term effects of TPE on mineral metabolism, warranting further investigation and adjustments in chronic TPE management.
Percent changes in total corrected calcium, phosphate, PTH, and FGF-23 from pre- to post-TPE (N=42)
Funding
- NIDDK Support