70-year-old female with nephrotic syndrome, burnt out chronic polyarthritis, autopsy specimen
- The glomeruli contain a red-staining amyloid in the capillary slings with irregular deposits in the area of the basal membrane as well as the mesangium
- In final stages, the glomerular structure is destroyed.
- The small arteries and arterioles contain homgenous amyloid deposits.
Immunohistochemistry: t In 90% of cases, amyloidosis in the kidney is usually of the AL-type.
Aetiology: Most commonly paraproteinaemia (e.g plasmacytoma). Chronic infection may also cause amyloidosis (AA-amyloidosis, serum-amyloid associated protein)
The congo red staining can be confirmed by green polarized light.