Immunoglobulin light chain amyloidosis: 2018 Update on diagnosis, prognosis, and treatment

Disease Overview Immunoglobulin light chain amyloidosis is a clonal, nonproliferative plasma cell disorder in which fragments of immunoglobulin light or heavy chain are deposited in tissues. Clinical features depend on organs involved but can include restrictive cardiomyopathy, nephrotic syndrome, hepatic dysfunction, peripheral/autonomic neuropathy, and “atypical multiple myeloma.” Diagnosis Tissue biopsy stained with Congo red demonstrating amyloid deposits with apple‐green birefringence is required for diagnosis. Invasive organ biopsy is not required because amyloid deposits can be found in bone marrow, salivary gland, or subcutaneous fat aspirate in 85% of patients. Verification that amyloid is composed of immunoglobulin light chains is mandatory. The gold standard is laser capture mass spectroscopy. Prognosis N‐terminal pro‐brain natriuretic peptide (NT‐proBNP), serum troponin T, and difference between involved and uninvolved immunoglobulin free light chain values are used to classify patients into four groups of similar size; median survivals are 94.1, 40.3, 14.0, and 5.8 months. Therapy All patients with a systemic amyloid syndrome require therapy to prevent deposition of amyloid in other organs and prevent progressive organ failure. Stem cell transplant (SCT) is preferred, but only 20% of patients are eligible. Requirements for safe SCT include systolic blood pressure >90 mm Hg, troponin T