Abstract: TH-PO1049
Occult Plasma Cell Dyscrasia Unmasked After 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
- Zaidi, Syed Haris Mustafa, Lehigh Valley Hospital - Cedar Crest, Allentown, Pennsylvania, United States
- Hutson, Stefan Charles, Lehigh Valley Hospital - Cedar Crest, Allentown, Pennsylvania, United States
- Bollu, Ravindra, Lehigh Valley Hospital - Cedar Crest, Allentown, Pennsylvania, United States
Introduction
Early allograft dysfunction is usually attributed to ischemic injury, rejection, calcineurin toxicity, obstruction, or vascular complications. Monoclonal gammopathy-related injury is rarely suspected after transplantation. We report a case in which oliguria and rising creatinine revealed occult kappa light-chain disease.
Case Description
A 67-year-old man with ESKD presumed due to hypertensive nephrosclerosis had been anuric on hemodialysis since 2015. He underwent living-related kidney transplantation from his sister on 11/5/25 with basiliximab/methylprednisolone induction and tacrolimus, mycophenolate, and prednisone maintenance. Urine output resumed, and he was discharged on 11/6/25 with serum creatinine 6.13 mg/dL. Three days later, he returned with oliguria, weakness, bilateral leg edema, Na 124 mEq/L, creatinine 8.72 mg/dL, BUN 47 mg/dL, urine protein-creatinine ratio 5.74, and tacrolimus level 7.6 ng/mL. Transplant ultrasound showed a 10.8-cm allograft without hydronephrosis, collection, stenosis, or thrombosis. Donor-specific antibodies, BK/CMV studies, and rejection surveillance were negative or low risk. Allograft biopsy showed mild acute tubular necrosis without rejection, but immunofluorescence revealed 2+ kappa light-chain staining. Serum free kappa light chains were 916.34 mg/L, lambda 13.29 mg/L, and kappa/lambda ratio 68.95. PET showed no lytic lesions. Bone marrow biopsy confirmed a kappa-restricted plasma cell neoplasm. He received high-dose dexamethasone followed by daratumumab-based therapy, with immunosuppression reduction. Kidney function improved, and urine protein-creatinine ratio fell to 0.37 by 2/9/26.
Discussion
This case shows that early allograft dysfunction is not always rejection. Although mild ATN was present, kappa-restricted staining redirected evaluation and led to diagnosis of plasma cell dyscrasia. Timing within days of transplantation favored a pre-existing occult disorder rather than de novo post-transplant myeloma, raising concern that native kidney failure attributed to hypertensive nephrosclerosis may have been misclassified. Key lessons are to pursue alternate diagnoses when imaging and immunologic tests are unrevealing, treat light-chain staining as meaningful, and coordinate multidisciplinary care to balance anti-myeloma therapy, immunosuppression, infection risk, and graft preservation.