Definition and Overview
Amyloidosis is a term used for a cluster of diseases characterized by the abnormal buildup of amyloid (a starch-like protein) in different body organs including the liver, kidneys, and spleen. The condition is very rare, affecting no more than 500,000 individuals in the world. Since it affects only a very small percentage of the population, it is classified as an orphan disease.
Just like many of the orphan diseases, amyloidosis is believed to have a genetic factor. People who have the condition are more likely to have it since birth although more obvious symptoms do not appear until they get older. Although the condition can be considered mild in some cases, it could be life-threatening for other patients. This is because as the deposits build up, they can invade the vital organs of the body and interfere with their function.
Some of the complications associated with amyloidosis are:
The inability of the kidneys to filter out wastes and other by-products more effectively, which may then lead to kidney failure
Heart problems including difficulty in pumping blood throughout the body, resulting in breathing problems. The deposits may also disrupt the electrical activity of the heart, further worsening the cardiovascular problem. In its worst case, it can result in heart failure.
Numbness and loss of sensation in the extremities as the deposits build up in the nervous system, especially the spine. When this happens, the person may not immediately react to the sudden change of temperature such as burning of the skin.
The buildup of the deposits can be localized (focused on one area of the body) but in the majority of the cases, it is systemic (occurring in multiple parts of the body).
Amyloidosis cannot be cured but can be managed with certain treatments like stem cell transplant and chemotherapy.
Causes of Condition
Numerous studies have cited multiple possible reasons for the condition, but experts are yet to determine the exact cause.
Amyloidosis can be:
Primary – Also known as AL or immunoglobulin light chain, this occurs due to the bone marrow's abnormal production of antibodies, which are responsible for keeping infection at bay and killing pathogens that enter the body. In patients with amyloidosis, the excess antibodies are not broken down but buildup in nearby organs instead.
Familial – Sometimes referred to as hereditary A, it means that a genetic factor may be involved in the increased production of the protein in the body. Specifically, transthyretin (TT) amyloid can gather either in the heart or the nervous system or both.
AA – Sometimes called secondary amyloidosis, this type mostly attacks the kidneys. However, there are cases wherein the deposit is found in the heart, liver, or the digestive tract, causing intestinal malabsorption (inability of the body to absorb the nutrients from food).
Certain environmental factors have also been associated with the development of amyloidosis such as long-term dialysis. The procedure can lead to the accumulation of certain blood proteins that are then deposited in the tendons and joints.
The condition can affect anyone. However, it’s more common among men who are at least 50 years old. Those who have been diagnosed with an inflammatory disorder such as rheumatoid arthritis or diseases that affect the plasma cells that produce the antibodies such as lymphoma or multiple myelomas are also at a high risk of developing the condition.
The symptoms can significantly vary depending on the location of the deposits. Usually, persons with amyloidosis have:
- Irregular or slow heartbeat
- Difficulty breathing or shortness of breath
- Pain in the joints
- Swelling, tenderness, or redness of the joints
- Changes in the color of the skin
- Weak control of the hand muscles
- Predisposition to hand-wrist conditions such as Carpal tunnel syndrome
- Difficulty in swallowing
- Unexplained weight loss
- Kidney failure
- Decreased output of urine
- Easy bruising of the skin
- Problems in the lungs
- Enlarged liver or spleen
Who to See and Treatments Available
It’s difficult to diagnose amyloidosis since the symptoms can also be attributed to other diseases or are extremely mild that patients do not seek medical intervention immediately.
Amyloidosis is diagnosed through a series of tests including physical exam, ultrasound of the abdomen, electrocardiograph (ECG) of the heart, and the conduction of nerve tests.
If the above tests suggest the presence of amyloidosis, the doctor will more likely to request for a biopsy where a sample of a fluid or tissue is obtained from the body and is studied for any presence of the protein. A commonly used method is called the abdominal fat pad aspiration, which is less invasive and thus less uncomfortable for the patient. A sterile needle that is specifically designed for biopsy is introduced into the skin until it reaches the fat pad where a sample is obtained. The protein’s presence is detected once the sample is exposed to Congo red stain dye.
There are cases wherein the condition is not diagnosed until the patient’s kidneys and liver begin failing. In these cases, the common first line of treatment is the stabilization of the failing organs that may require organ transplantation depending on the severity of the condition.
The disease is treated the same way doctors manage multiple myelomas since this type of cancer also begins with plasma cells. Treatment options include chemotherapy, combination therapy, or stem cell transplant.
Supportive treatments are also used to reduce or manage the symptoms, particularly for patients with AA amyloidosis, since the disease is commonly associated with chronic infection or inflammatory disease. These include a change in diet (most especially if the problem affects the digestive tract), close supervision of the symptoms and the affected organ, and medically supervised intake of medications.
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