New Insights and Modern Treatment of AL Amyloidosis

Systemic amyloidosis is a rare disease that is rarely cured. Systemic immunoglobulin light-chain amyloidosis (AL) is the most common type, usually the result of monoclonal light chains produced by a relatively indolent small plasma cell clone in the bone marrow. In AL, the direct toxicity of light chains, their misfolded intermediates, and deposition as amyloid fibrils in vital organs cause organ dysfunction and death. Often the diagnosis is delayed and the disease is advanced at presentation. Early diagnosis is possible with vigilance in clinical situations such as for patients with monoclonal gammopathy of undetermined significance who develop albuminuria or elevated cardiac biomarkers. Treatment is aimed at eradicating the clonal disease and restoring organ function; options include high dose melphalan followed by autologous stem cell transplantation, oral melphalan and dexamethasone, bortezomib-based combination chemotherapy and immunomodulatory agents such as lenalidomide or pomalidomide combined with dexamethasone. Cardiac involvement at baseline and the free light-chain hematologic response to therapy determine overall survival. Following measures of organ disease with cardiac and other biomarkers and of hematologic disease with serum free light chains is necessary to gauge organ and hematologic responses to therapy.