AA Amyloidosis
Causes of AA Amyloidosis
AA amyloidosis develops when a person has a medical condition or other disorder that causes sustained inflammation in the body. The ‘inflammatory response’ is a normal part of the body’s response to infection or other internal threats. During the inflammatory response different chemicals and molecules are activated to deal with the threat, and one of these is called serum amyloid A protein (SAA).
SAA is the precursor protein in AA amyloidosis.
SAA is a protein that is normally found in the blood in low concentrations, but production is ramped up when there is inflammation in the body.
Some severe rare inflammatory conditions that are caused by genetic mutations lead to a sustained, exaggerated inflammatory response with very high abnormal SAA levels that fluctuate; under these conditions the high SAA levels may lead to amyloid deposition. In some chronic conditions the inflammatory response may not be as pronounced, and SAA levels may remain in the low to medium abnormal range for many years; this long term exposure to moderately elevated SAA levels can also lead to the formation of amyloid deposits.
Chronic inflammatory disorders
- Inflammatory arthritis
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- Rheumatoid arthritis
- Psoriatic arthritis
- Gout
- Autoinflammatory diseases
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- Familial Mediterranean fever (FMF)
- Cryopyrin-associated periodic syndrome (CAPS)
- Mevalonate kinase deficiency (MKD)
- TNF receptor-associated periodic syndrome (TRAPS)
- Inflammatory bowel disease
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- Ulcerative colitis
- Crohn’s disease
Chronic infections
- Rheumatoid arthritis
- Psoriatic arthritis
- Gout
- Injected drug abuse-related infections
Blood-related (haematological) conditions
- Myeloma
- Non-Hodgkin lymphoma
- Castleman’s disease
Other cancers (solid tumours)
- Lung cancer
- Sarcoma
- Kidney cell carcinoma
AA Amyloidosis Symptoms
- Swollen feet and ankles (oedema)
- Foamy or frothy urine
- Fatigue
- Low blood pressure
- Nausea and vomiting
- Dry and itchy skin
- Muscle cramps
- Loss of appetite
Diagnosing AA Amyloidosis
Because kidney problems are usually the first manifestation of the condition, your doctor will want to perform a kidney biopsy and examine the kidney tissue under a microscope to look for amyloid deposits. Once amyloid deposits are seen, further tests must be done on the tissue sample to identify exactly what type of amyloidosis you have.
This is a crucial step as many types of amyloidosis affect the kidneys, and there are different treatments for different types. Your doctor will also do blood and urine tests to look at how your kidneys are functioning.
You may also have tests to look at your heart function; this because the kidneys and heart work closely together so problems with one might lead to problems with the other.
Treating AA Amyloidosis
Because kidney problems are usually the first manifestation of the condition, your doctor will want to perform a kidney biopsy and examine the kidney tissue under a microscope to look for amyloid deposits. Once amyloid deposits are seen, further tests must be done on the tissue sample to identify exactly what type of amyloidosis you have.
This is a crucial step as many types of amyloidosis affect the kidneys, and there are different treatments for different types. Your doctor will also do blood and urine tests to look at how your kidneys are functioning.
You may also have tests to look at your heart function; this because the kidneys and heart work closely together so problems with one might lead to problems with the other.