Histopathology - Amyloidosis

Front 1

Physical nature of amyloid

1. On election microscope 🔬

2. On X-ray crystallography and infrared spectroscopy

3.

Back 1

1. On EM - amyloid is seen to be made up largely of continuous, non branching fibrils with a diameter of ~7.5 - 10 nm

This EM structure is identical in all types of amyloidosis

2. On X-ray crystallography and infrared spectroscopy show a characteristic cross-β-pleated sheet conformation

Front 2

Amyloid material consist of ?

Back 2

Fibril proteins 95%

remaining 5% p- component and other glycoproteins

Front 3

The major forms of amyloid

List some minor forms

Back 3

1. AL amyloid

2. AA amyloid

3. Aβ amyloid

Minor

1. TTR - transthyretin - normal serum protein that binds and transports thyroxine and retinol

2. β2 - microglobulin - a component of MHC class I Molecules and a normal serum protein, has been identified as the amyloid Fibril subunit Aβ2m in amyloidosis that complicates the course of patients on long term haemodialysis

3. Prion proteins - CNS, local amyloidosis

Front 4

About AL protein

1. Is made up of?

Back 4

1. Complete immunoglobulin light chains, the amino-terminal fragments of light chains or both

2. Most are lamda chains or their fragments

But in some cases kappa k - chains have been identified

3. The amyloid Fibril protein of the AL type is produced from Free If light chains secreted by a monoclonal population of plasma cells and it's deposition is associated with certain forms of plasma cells tumors

Front 5

About AA amyloid Fibril

Back 5

1. MW - 8500 ,

2. 76 amino acid residues

Front 6

Serum amyloid o may contribute to amyloid deposition by?

Back 6

Stabilizing the fibrils

and decreasing their clearance