Amyloidosis

Excerpt

Amyloidosis is a heterogeneous disease that results from the deposition of toxic insoluble beta-sheet fibrillar protein aggregates in different tissues. Amyloidosis can be acquired or hereditary. The disease can be localized or systemic. Amyloid can accumulate in the liver, spleen, kidney, heart, nerves, and blood vessels, causing different clinical syndromes, including cardiomyopathy, hepatomegaly, proteinuria, macroglossia, autonomic dysfunction, ecchymoses, neuropathy, renal failure, hypertension, and corneal and vitreous abnormalities.

Previously multiple classification systems have been devised to classify different types of amyloidosis. In modern times it has been classified according to the chemical analysis of amyloid clinical entities. Amyloidosis can be classified according to systemic, hereditary, central nervous system, ocular, and localized etiology. However, the most common types are AL, AA, ATTR (amyloid transport protein transthyretin), and dialysis-related amyloidosis (beta2M type).

In AL amyloidosis, 'A' represents amyloid followed by the associated fibrillar protein, 'L' means light chain fragment or immunoglobulin light chain. In AA amyloidosis, the second A stands for the serum amyloid A protein.