[1687] Progressing Amyloid Light Chain (AL) Deposits in the Kidney in Patients with Autologous Hematopoietic Stem Cell Transplant for Monoclonal Gammopathy

Rachel Roth, Tibor Nadasdy, Anjali Satoskar, Gyongyi Nadasdy, Lee Hebert, Sergey V Brodsky. The Ohio State University, Columbus, OH

Background: Systemic light chain (AL) amyloidosis is a condition in which the amyloid protein (amyloidogenic light chain) is abnormally deposited in the extracellular matrix of multiple organs/tissues in patients with monoclonal gammopathy. The mainstay of treatment for monoclonal gammopathy includes autologous hematopoietic stem cell transplantation (AHSCT). The success of AHSCT is usually confirmed by the absence of monoclonal protein in the serum and urine. Amyloidosis progression is usually inhibited or reversed in patients after successful treatment.
Design: Herein, we present observations made on two patients who continued to develop progressive AL amyloidosis in the kidneys with worsening renal function despite the absence of monoclonal protein in the serum and urine after AHSCT for monoclonal gammopathy.
Results: For the first patient, kidney biopsies were performed before AHSCT and nine years after transplant. These two biopsies indicated progressive renal amyloid deposition. The renal biopsy of the second patient, performed three years after AHSCT, also showed severe amyloid deposits. Renal function was significantly deteriorating in both patients. For patient #1, serum creatinine was 1.40 mg/dl before stem cell transplantation and 3.05 mg/dl at the time of the second renal biopsy. For patient #2, serum creatinine was 2.00 mg/dl before the stem cell transplantation and 4.70 mg/dl at the time of the kidney biopsy. Numerous immunofixation and protein electrophoresis tests were negative for monoclonal protein both in serum and urine following transplantation, and both of these patients were considered to be in remission for their monoclonal gammopathy.
Conclusions: Progression of AL amyloidosis with no clinical signs of monoclonal gammopathy after successful AHSCT has not yet been described. Our findings indicate the possibility of a small population of neoplastic plasma cells persisting in patients following treatment. We hypothesize that the amount of monoclonal protein produced by these cells is miniscule and may not be detected by the current routine clinical tests. Close monitoring of the renal function and proteinuria as well as follow-up renal biopsies are warranted in patients who underwent AHSCT secondary to AL amyloidosis even in the absence of monoclonal protein by clinical tests. The clinicians involved in the care of patients with AL amyloidosis should be aware of this potential progression of AL amyloidosis in the kidney.
Category: Kidney (does not include tumors)

Wednesday, March 21, 2012 1:00 PM

Poster Session VI # 303, Wednesday Afternoon


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