Serum Amyloid- Associated Protein
AA protein is composed of protein which is derived from larger precursor protein in the serum called SAA (serum amyloid- associated protein) with molecular weight of 8.5-kD .
It is a disease characterized by the abnormal deposition of fibers of insoluble protein in the extracellular space of various tissues and organs. It is characterized by a protein called “serum amyloid A. SAA circulates in plasma association with HDL3 (high-density lipoprotein). SAA is an acute phase reactant protein synthesized in the liver, in response to chronic inflammatory and infectious conditions.
It isn’t normally found in the body, but it can be formed from several different types of protein. Organs that may be affected include the heart, kidneys, liver, spleen, nervous system and digestive tract.
However, in amyloidosis, a protein might alter form (or “misfold”) and become unable to be eliminated. Misfolded proteins cluster together to produce amyloid fibrils, which are then deposited between the cells of important organs. The cells in one or more tissues and organs can no longer work together when amyloid fibrils build up, and the organ(s) loses function.
Sign and symptoms of Amyloidosis-
Sign and symptoms are dependent on which organ is affected
- Swelling of the feet or legs
- Foamy/frothy urine
- Urinating less
Stomach or intestines:
- Swelling of the feet or legs
- Shortness of breath
- Chest pain
Other signs and symptoms:
The diagnosis of amyloid disease can be made from the following investigations:
1. Tissue diagnosis- The two confirmed methods of tissue diagnosis of amyloidosis are routine evaluation of biopsy or fine needle aspiration, followed by Congo red staining and examination under polarised microscopy.
2. In vivo Congo red test– In a living patient, a known amount of Congo red dye can be administered intravenously. If amyloidosis is present, the dye becomes attached to amyloid deposits and its blood levels drop fast. However, due to the danger of allergy from the injected dye, the test is not widely used.
3. Other tests– Protein electrophoresis, immunoelectrophoresis of urine and serum, and bone marrow aspiration. These are supportive but not confirmatory of amyloidosis .
In Amyloidosis, first to treat infection or inflammation, which will lower the level of SAA protein, which is the precursor of AA amyloid plaques. Depending on the underlying disease, these therapies will differ. Blood tests that assess inflammation in the blood, such as sedimentation rate and C-reactive protein levels, can be used to monitor the success of this medication. Surgery for the infection or tumour, medication therapy for rheumatoid arthritis, antibiotics for persistent infection, and the usage of colchicine for FMF (Familial Mediterranean Fever) are only a few of the treatments available for inflammatory illnesses.
Amyloidosis is a chronic (long-term) and progressive (slowly worsening) condition. There is a considerable danger of death if the condition is not treated. Early detection is crucial for controlling the condition before it progresses.