Amyloidosis (am-uh-loi-DO-sis) is a rare disease that occurs when a substance called amyloid builds up in your organs. Amyloid is an abnormal protein that is usually produced in your bone marrow and can be deposited in any tissue or organ. Amyloidosis can affect different organs in different people, and there are different types of amyloid. Amyloidosis frequently affects the heart, kidneys, liver, spleen, nervous system and digestive tract. Severe amyloidosis can lead to life-threatening organ failure.
The aggregates form protofilaments that associate into amyloid fibrils. In all types of amyloidosis, glycosaminoglycan moieties of proteoglycans and serum amyloid P (SAP) protein interact with the amyloid fibrils or deposits, promoting fibril formation and stability in tissue . Organ dysfunction results from disruption of tissue architecture by amyloid deposits. However, increasing evidence indicating that amyloidogenic precursor proteins or precursor aggregates have direct cytotoxic effects that also contribute to disease manifestations is emerging.
Less than 15% of patients display the physical characteristics typically associated with amyloidosis i.e. enlargement of tongue, submandibular, swelling, and facial purpura in the US (Amyloidosis: Recognition, Prognosis and Conventional Therapy, American Society of Hematology). Less than 1% of patients with amyloidosis have tongue enlargement in the US. In 33-40% of amyloidosis patients, the kidney is affected in the US (Amyloidosis: Recognition, Prognosis and Conventional Therapy, American Society of Hematology)