Light Chain Amyloidosis

Light Chain Amyloidosis results from clonal plasma cell proliferation producing excessive amounts of misfolded immunoglobulin light chains (kappa or lambda) that cannot be properly degraded. These misfolded proteins aggregate to form amyloid fibrils that deposit in various tissues, causing progressive organ dysfunction. The heart is affected in approximately 50-70% of patients, leading to restrictive cardiomyopathy with diastolic dysfunction, arrhythmias, and sudden cardiac death. Renal involvement occurs in 40-50% of patients, presenting as nephrotic syndrome with heavy proteinuria. Peripheral neuropathy develops in approximately 10-15% of patients, ranging from small fiber neuropathy to autonomic dysfunction. Other affected organs include liver, eyes, gastrointestinal tract, and soft tissues. The underlying plasma cell clone is usually modest in size and may not meet criteria for multiple myeloma. Early diagnosis is critical, as untreated disease rapidly progresses to multi-organ failure. Median survival without treatment is approximately 2-4 years when cardiac involvement is present.