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.A detailed elaboration of the pathogenesis of AL amyloidosis is beyond the scope of this article, but a few points warrant discussion. A key feature of all types of amyloidosis is abnormal folding of a protein that is normally soluble.
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. Less than 1% of patients with amyloidosis have tongue enlargement in the US (Amyloidosis: Recognition, Prognosis and Conventional Therapy, American Society of Hematology).In 33-40% of amyloidosis patients, the kidney is affected in the US (Amyloidosis: Recognition, Prognosis and Conventional Therapy, American Society of Hematology)