Abstract: SA-PO0794
A Rare Case of ALH Amyloidosis
Session Information
- Glomerular Diseases: Lupus Nephritis, Monoclonal Gammopathy-Related Disease, and Transplantation
October 24, 2026 | Location: Exhibit Hall A, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Glomerular Diseases
- 1402 Glomerular Diseases: Clinical, Outcomes, and Therapeutics
Authors
- Singh, Harminder, University of Illinois Chicago, Chicago, Illinois, United States
- Ricardo, Ana C., University of Illinois Chicago, Chicago, Illinois, United States
- Setty, Suman, University of Illinois Chicago, Chicago, Illinois, United States
- Avila, Ana Maria, University of Illinois Chicago, Chicago, Illinois, United States
Introduction
Amyloidosis is a systemic disease caused by deposition of misfolded proteins leading to organ dysfunction. Multiple precursor proteins have been identified that may form amyloid. In particular, monoclonal-related amyloidosis includes light chain, heavy chain, and a less common heavy and light chain subtype (ALH). We present a rare case of kappa light chain and gamma heavy chain amyloidosis (ALH amyloid).
Case Description
This is a 69-year-old male with medical history of hypertension and recent unprovoked DVT, who was referred to the renal clinic for nephrotic syndrome (urine albumin-creatinine and protein-creatinine ratio 2.5 g/g and 3.9 g/g, respectively) and serum creatinine of 1.3-1.4 mg/dL. Serum immunofixation yielded a monoclonal IgG kappa spike with serum kappa-lambda free light chain ratio of 2.5:1. Additional glomerular disease serologic workup was unrevealing. Bone marrow biopsy showed 5% polyclonal plasma cells but B cell clonality by PCR and next generation sequencing revealed IgG-Clonal rearrangement. Kidney biopsy demonstrated marked glomerular basement membrane (GBM) thickening with mesangial expansion, pale PAS and Congo red positivity, diffuse foot process effacement, and randomly arranged 9–10 nm fibrils within the GBM, mesangium, and peritubular capillary walls. Mass spectrometry confirmed ALH amyloidosis. In addition to renin-angiotensin system blockade, treatment with 6 cycles of cyclophosphamide, bortezomib, dexamethasone, and daratumumab, followed by 6 months of daratamumab maintenance, resulted in renal very good partial and complete hematologic responses.
Discussion
ALH amyloidosis is a rare entity with limited cases reported in the literature and is not yet formally recognized as a subtype by the International Society of Amyloidosis. Diagnosis may be missed with inadequate tissue sampling, though proteomic studies improve detection rates. Treatment targets the underlying clone, and renal response is monitored by proteinuria.