Patient with AL amyloidosis with recurrent syncope as the first symptom: case report and literature review

Immunoglobulin light-chain (AL) amyloidosis is a rare systemic disease caused by the extracellular deposition of misfolded light chains. Nonspecific manifestations, especially those dominated by severe autonomic neuropathy, frequently delay diagnosis.

A 68-year-old woman was admitted after five months of recurrent syncope. The clinical picture was dominated by refractory orthostatic hypotension, nausea and vomiting alternating with diarrhea and constipation, stocking-glove paresthesias, and proteinuria. Bone marrow examination showed the presence of clonal plasma cells with positive M protein, which was confirmed by the serum free light chain test. AL amyloidosis was diagnosed based on positive Congo red staining in renal biopsy specimens. The patient was enrolled in a daratumumab-based protocol combined with daratumumab, bortezomib, cyclophosphamide, and dexamethasone. After three cycles, complete hematological remission was achieved, and the autonomic nerve function improved gradually over the subsequent six months.

This case and literature review suggest that AL amyloidosis should be considered whenever a patient presents with multisystem dysfunction dominated by autonomic nerve dysfunction. Although such presentations are associated with poor prognosis, prompt initiation of daratumumab-based therapy can produce rapid hematologic remission and clinically meaningful improvement.