A 55-year-old diabetic Raj from Mumbai has a long history of renal failure. He is currently waiting for an organ for transplant and has been on hemodialysis in the interim. If this man develops amyloid deposits around his joints, they are likely to be composed of which of the following substances?
Amyloid deposits appear similar by light and electron microscopy, but actually represent a heterogeneous population of proteins that have a common teiary structure forming a beta-pleated sheet. Questions about the type of amyloid seen in different disease states are orites on examinations. Here are two tables to help you out: Systemic amyloidosis: Chronic active diseaseAA amyloid from serum amyloid- associated (SAA) protein from liver (choice A)Myelomas and related diseasesAL amyloid from immunoglobulin light chain (choice B)Chronic hemodialysisBeta2 microglobulin (related to high plasma levels) (choice C)Nephropathic hereditary forms (familial Mediterranean fever)AA amyloid from SAA (choice A)Cardiomyopathic hereditary forms (senile systemic amyloidosis)Prealbumin/transthyretin Neuropathic hereditary syndromesPrealbumin/transthyretin Localized amyloidosis: Senile cardiac amyloidosisAtrial natriuretic peptide-related fibrilsCerebral amyloid in Alzheimer disease, Down syndromeCerebral amyloid in Alzheimer disease, Down syndromeMedullary carcinoma of thyroidCalcitonin precursors (choice D)Isolated, massive, nodular deposits (skin, lung, urogenital tract)AL from light chains (choice B)
Amyloid-associated protein
Amyloid light chains
Beta2 microglobulin
Calcitonin precursors