Increased serum free light chains precede the presentation of immunoglobulin light chain amyloidosis.

Purpose: Patients with immunoglobulin light chain amyloidosis (AL amyloidosis) generally present with advanced organ dysfunction and have a high risk of early death. We sought to characterize monoclonal immunoglobulin (M-Ig) light chains before clinical presentation of AL amyloidosis.

Patients And Methods: We obtained prediagnostic sera from 20 cases with AL amyloidosis and 20 healthy controls matched for age, sex, race, and age of serum sample from the Department of Defense Serum Repository.