What is Amyloidosis ?
This non-contagious disease is characterized by the formation of protein deposits that alter the normal functioning of organs. It evolves most often to a severe form and can affect all organs. The total number of people affected in France by this rare disease is not precisely known, but it is estimated that it affects 1 in 100,000 people. (1) About 500 new cases of AL amyloidosis are diagnosed each year in France. the least rare form of the disease.
Symptoms of Amyloidosis
Amyloid deposits can potentially appear in almost all tissues and organs of the body. An amyloidosis usually progresses to a severe form by gradually destroying the organs affected: the kidneys, the heart, the digestive tract and the liver, are the organs most often affected. But amyloidosis can also affect bones, joints, skin, eyes, tongue …
Consequently, the range of symptoms is very wide: malaise and shortness of breath when the heart is affected, edema of the legs with regard to the kidney, loss of muscle tone when the peripheral nerves are affected, diarrhea / constipation and occlusion in the case of digestive tract, etc. Acute symptoms such as shortness of breath, diarrhea and bleeding should alert and lead to amyloidosis screening.
The origins of the disease
Amyloidosis is caused by changing the molecular structure of a protein, making it insoluble in the body. The protein then forms molecular deposits: the amyloid substance. It is more accurate to speak of amyloidosis than of amyloidosis, for if this disease has the same cause, its expressions are very diverse. Indeed, about twenty proteins are responsible for as many specific forms. Three types of amyloidosis, however, predominate: AL (immunoglobulin), AA (inflammatory) and ATTR (transthyretin).
- AL amyloidosis results from the multiplication of certain white blood cells (plasma cells). They produce antibodies (immunoglobulins) that will aggregate and create deposits.
- AA amyloidosis occurs when chronic inflammation leads to a high production of SAA proteins that will form amyloidosis in the tissues.
- Transthyretin protein is involved in ATTR amyloidosis. This form of the disease is genetic. A parent with a 50% risk of passing the mutation to their child.
Amyloidosis is not contagious. Epidemiological data clearly indicate that the risk increases with age (amyloidosis is often diagnosed around 60-70 years). People with an infectious or inflammatory disease, as well as those who have had a long dialysis, are more vulnerable. Since some forms of amyloidosis, such as ATTR amyloidosis, are linked to an inherited genetic mutation, families with one or more members affected must be monitored.
Prevention and treatment
To date, there is no means of prevention to fight against amyloidosis. The treatments all involve decreasing the production of the toxic protein that is deposited and aggregates in the tissues, but they vary according to type of amyloidosis:
- By chemotherapy in the case of AL amyloidosis. The drugs used in its treatment show ” a real efficiency, ” says the National Society of Internal Medicine (SNFMI), while stating that the heart attack remains serious.
- Using powerful anti-inflammatory drugs to fight the inflammation that caused AA amyloidosis.
- For ATTR amyloidosis, transplantation may be necessary to replace a liver colonized with the toxic protein.
The French Association against Amyloidosis publishes a lot of information about this disease and its treatments, for the sick and their relatives.