Difference between revisions of "Amyloidosis"
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| − | + | ==Introdcution== | |
| − | + | Amyloid infiltration occurs in all species - amaloid is an inert substance that becomes deposited under the endothelium and basement membranes of a variety of tissues, notably the renal glomeruli, | |
| − | + | [[Pancreas - Anatomy & Physiology#Endocrine|Islets of Langerhans]] in the [[Pancreas - Anatomy & Physiology|pancreas]] and the [[Liver - Anatomy & Physiology|liver]] (between the sinusoidal reticulum and the hepatic cords). | |
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| − | + | ==Causes== | |
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May be a primary condition or appear secondary to some chronic tissue destructive process | May be a primary condition or appear secondary to some chronic tissue destructive process | ||
*an infectious process elsewhere in the body | *an infectious process elsewhere in the body | ||
*a result of sustained antigenic stimulation, eg repeated injections with an antigenic substance or production of excessive antibody by leukocytes | *a result of sustained antigenic stimulation, eg repeated injections with an antigenic substance or production of excessive antibody by leukocytes | ||
| − | + | ==Gross Pathology== | |
*pale (greyish waxy appearance) | *pale (greyish waxy appearance) | ||
*enlarged | *enlarged | ||
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*firm | *firm | ||
*very prone to rupture | *very prone to rupture | ||
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====Microscopically==== | ====Microscopically==== | ||
*deposition of amyloid in the space of Disse | *deposition of amyloid in the space of Disse | ||
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==Arterial== | ==Arterial== | ||
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Amyloid is an eosinophilic, homogenous, hyaline material. Due to its beta-pleated-sheet structure it is almost insoluble. Amyloid may be: | Amyloid is an eosinophilic, homogenous, hyaline material. Due to its beta-pleated-sheet structure it is almost insoluble. Amyloid may be: | ||
*'''AA''': Serum amyloid A, alpha-2 globulin. | *'''AA''': Serum amyloid A, alpha-2 globulin. | ||
Revision as of 11:16, 3 November 2010
Introdcution
Amyloid infiltration occurs in all species - amaloid is an inert substance that becomes deposited under the endothelium and basement membranes of a variety of tissues, notably the renal glomeruli, Islets of Langerhans in the pancreas and the liver (between the sinusoidal reticulum and the hepatic cords).
Causes
May be a primary condition or appear secondary to some chronic tissue destructive process
- an infectious process elsewhere in the body
- a result of sustained antigenic stimulation, eg repeated injections with an antigenic substance or production of excessive antibody by leukocytes
Gross Pathology
- pale (greyish waxy appearance)
- enlarged
- rounded edges
- firm
- very prone to rupture
Microscopically
- deposition of amyloid in the space of Disse
- shows 'apple-green' fluorescence under polarised light after staining with Congo Red
Arterial
Amyloid is an eosinophilic, homogenous, hyaline material. Due to its beta-pleated-sheet structure it is almost insoluble. Amyloid may be:
- AA: Serum amyloid A, alpha-2 globulin.
- AL: Derived from immunoglobulin light chains.
Disease may be truly idiopathic (dogs and cats) or may be secondary to another disease process, often chronic inflammation or neoplasia. Chronic antigenic stimulation induces the overproduction of AA protein which may become deposited throughout the body.
Deposits are found:
- Renal vessels and glomeruli.
- Splenic white pulp.
- Space if Disse.
- Coronary arteries.
- Meningeal arteries.
Affected organs are non-functional and appear waxy and pale.