Amyloidosis is the term given to a group of diseases in which the underlying pathogenesis is caused by the accumulation of amyloid, an abnormal, insoluble protein extracellularly. Protein misfolding transforms soluble precursor proteins into insoluble amyloid fibrils. There are 4 main types of amyloidosis- AL (light chain), AA (inflammation), ATTR (hereditary and old age), and AB2M (caused by dialysis).
Amyloid fibrils can disseminate systemically and into organs, which eventually causes organ failure. Deposition in cardiac tissue, kidneys and central nervous system are the main causes of patient deterioration. Light chain amyloidosis, also known as AL amyloidosis due to clonal plasma cell dyscrasia is the most common type, with its incidence comparable to Hodgkin’s lymphoma or CML. This type usually affects the renal, cardiac, nervous and hepatic systems. It can occur alone or in conjunction with multiple myeloma, Waldenstroms macroglobulinemia or non-Hodgkin lymphoma.