Amyloid Light-Chain (AL) Amyloidosis in a Middle-Aged Lady: Confronting the Challenges of a Rare Diagnosis in a Developing Country

Amyloid light-chain (AL) amyloidosis, which results from monoclonal light-chain deposition from plasma cell dyscrasia, is often identified in old patients. A 37-year-old lady presented with frothy urine and constipation with constitutional symptoms for two months duration. On examination, she had tender hepatomegaly with cervical lymphadenopathy. She was found to have sub-nephrotic-range proteinuria, while serum protein electrophoresis revealed a monoclonal band of 17 g/l. Bone marrow aspiration and biopsy showed evidence of plasma cell dyscrasia with 20% of pleomorphic plasma cells. Myeloma-defining events were negative with normal serum calcium and serum creatinine, a haemoglobin of 10.5 g/dl, no lytic lesions on low-dose whole-body computed tomography, and involved-to-uninvolved serum free light-chain ratio of 8 with involved lambda light chains of 126.21 mg/l (4.23-27.69). Renal and lymph node biopsies demonstrated an eosinophilic amorphous material which showed apple-green birefringence on a Congo red stain suggestive of amyloidosis. Bone marrow aspiration, trephine biopsy, and lymph node biopsy together with renal biopsy led to the diagnosis of AL amyloidosis. She was classified as a stage 1 disease according to the Revised Mayo Clinic staging system. She was treated with a total of nine cycles of cyclophosphamide, bortezomib, and dexamethasone (CycloBorDex), where she achieved a very good partial response as a haematological response and an improvement in 24-hour urine protein excretion as an organ response. This was followed by an autologous bone marrow transplant in the transplant centre. Six months after the bone marrow transplant, it showed a slight progression of disease with an increased difference between involved and uninvolved free light chain (dFLC) with raised 24-hour urinary excretion for which we are planning to restart chemotherapy cycles with VRD (bortezomib-lenalidomide-dexamethasone) as daratumumab is not affordable in our country. Despite the low incidence of AL amyloidosis before the age of 40, this case highlights the monoclonal gammopathy workup in patients with high clinical suspicion, regardless of age. Targeted biopsies should be performed to confirm the diagnosis and start the treatment early to prevent organ failure. Despite the early diagnosis and treatment of AL amyloidosis with conventional chemotherapy, limited accessibility to optimum treatment options in disease progression is a major drawback in managing patients in developing countries.