Immunoglobulin light chain (AL) amyloidosis (previously referred to as primary amyloidosis), light chain deposition disease (LCDD), and heavy chain deposition disease (HCDD) are monoclonal plasma cell proliferative disorders that are characterized by tissue deposits of light chain or heavy chain fragments, leading to organ dysfunction. The incidence of AL amyloidosis is approximately one-tenth that of multiple myeloma. In approximately 10 percent of patients with AL amyloidosis, multiple myeloma is also present at the time of initial diagnosis; the clinical course and treatment of these patients is dependent on which of the two diseases is dominant in terms of end-organ damage and symptoms. Less than 1 percent of patients with isolated AL amyloidosis at diagnosis develop multiple myeloma at a future time point.
The prognosis and treatment of AL amyloidosis will be reviewed in detail here. The treatment of LCDD and HCDD is also reviewed briefly. The pathogenesis, clinical features, and diagnosis of these disorders and the diagnosis of primary amyloidosis are discussed in detail separately. (See "Pathogenesis of immunoglobulin light chain (AL) amyloidosis and light and heavy chain deposition diseases" and "Clinical presentation, laboratory manifestations, and diagnosis of immunoglobulin light chain (AL) amyloidosis (primary amyloidosis)".)
Assessment — To best treat patients with AL amyloidosis, the initial evaluation must confirm the diagnosis, establish the extent and sites of disease, and evaluate for comorbidities that are likely to have an impact on treatment options. The diagnosis of AL amyloidosis is presented separately. (See "Clinical presentation, laboratory manifestations, and diagnosis of immunoglobulin light chain (AL) amyloidosis (primary amyloidosis)".)
In addition to a history and physical examination, it is our practice to perform the following pre-treatment studies in patients with AL amyloidosis:
●Laboratory studies include a complete blood count with differential, chemistries with liver and renal function and electrolytes, prothrombin time (PT), partial thromboplastin time (PTT), electrophoresis of the serum and urine, immunoelectrophoresis of the serum and urine, serum free light chain assay, 24-hour urinary protein and creatinine clearance, brain natriuretic peptide (BNP), troponin, NT-proBNP, thyroid stimulating hormone (TSH), and cortisol level. Factor X levels should be included for patients with abnormal bleeding or abnormal PT/PTT testing.