[1490] De Novo AL Amyloidosis in Kidney Allograft.
Sanjeev Sethi, Samih Nasr, Mary Fidler, Lynn Cornell, Qi Qian. Mayo Clinic, Rochester
Background: Delayed onset of proteinuria in a renal allograft kidney can result from the development of transplant glomerulopathy, recurrent glomerular disease, diabetic nephropathy, etc. In this study, we describe a novel cause of proteinuria in the renal allograft
Design: We reviewed the clinicopathologic features of 4 kidney transplant patients (pts) who developed proteinuria late in the course. Renal allograft biopsy in all 4 pts showed de novo AL amyloidosis.
Results: Four pts who received a renal allograft 16, 18, 28 and 31 yrs ago developed proteinuria and progressive kidney dysfunction. Renal allograft biopsy showed AL amyloidosis in all renal compartments. Serum immunofixation performed after the kidney biopsy revealed monoclonal lambda light chains in all 4 pts. Bone marrow biopsy showed >10% plasma cells in 1 pt, 5-10% plasma cells in 2 pts, and <5% plasma cells in 1 pt. On follow up, 2 pts developed allograft failure. One of these two underwent autologous stem cell transplant which resulted in a complete hematological response. However, the remission did not prevent renal allograft failure. This pt received a second kidney transplant, which shows no evidence of allograft amyloidosis 1 yr post transplant. Of the remaining 2 pts, one suffered a sudden death during preparation for stem cell harvest and the other one was treated with prednisone and bortezomib which appears to have stabilized kidney function.
| Case 1 | Case 2 | Case 3 | Case 4 | |
| Age/sex | 59/M | 60/M | 45/F | 62/M |
| Yrs between transplant and proteinuria | 16 | 28 | 18 | 31 |
| Native kidney disease | IgA nephropathy | GN 1 | Bx of medulla, no amyloid | Congenital hypoplastic kidney |
| Immunosuppression | Cyclosporin/prednisone | Azathioprine/prednisone | Cyclosporin/prednisone | Azathioprine/prednisone |
| Symptoms* | Edema, foamy urine | Edema, foamy urine | UTI, 20 LB wt loss | None |
| S. creatinine* (baseline Cr) | 4.4 (1.6 to 2.0) | 1.4 (1.4) | 1.8 (0.7-1.0) | 1.3 (1.3-1.5) |
| U. protein *, g/24hr | 10 | 8 | 2.5 | 1.4 |
| S. albumin*, g/dL | 2.0 | 2.0 | 2.9 | 3.9 |
| Immunofixation | Lambda | Lambda | Lambda | Lambda |
| Bone marrow* | <5% plasma cells, no clonality | 10% lambda light chain restricted plasma cells | 5% lambda light chain restricted plasma cells | 5-10% lambda light chain restricted plasma cells |
| Amyloid treatment | Prednisone/Melphalan | Prednisone/ Bortezomib | Autologous stem cell transplantation | Prednisone/Melphalan |