Amyloidosis

February 3, 2017

Amyloidosis is defined as a group of diseases in which one or more organ systems in the body accumulate amyloid proteins. It is a condition in which too much of amyloid protein collects in the organs, so that they are not able to work normally. Amyloidosis can affect the heart, kidneys, liver, spleen, nervous system, stomach or intestines. The condition is rare (affecting fewer than 4,000 people in the United States each year), but it can be fatal.

Amyloidosis is a rare and serious protein deposition disease. It is caused by an abnormal protein called amyloid that builds up in tissues or organs. These abnormal protein deposits (or amyloid) are relatively insoluble and therefore cannot be easily broken down by the body. As the amount of amyloid protein deposits increase in a tissue or organ, they interfere with the tissue or organ’s healthy function. Eventually, the amyloid protein deposits cause symptoms and organ failure.

Types of Amyloidosis –

Light chain (AL) amyloidosis -This is the most common type of amyloidosis in the United States. The amyloid proteins that build up in the tissues in this condition are known as light chains. They can either be kappa or lambda light chains. AL amyloidosis is a disorder of the plasma cells. Plasma cells are a type of white blood cell responsible for the production of immunoglobulins or antibodies, a type of protein that fights infection. In AL amyloidosis, these proteins are misshapen and produced in excess. They deposit in tissues, causing organ damage. AL amyloidosis can affect one or more organs. The heart, kidneys, nerves, and gastrointestinal system are the most common organs affected. Because AL amyloidosis is associated with the overproduction of plasma cell proteins, it is linked to multiple myeloma.

Autoimmune (AA) amyloidosis – In this condition, the amyloid protein that builds up in the tissues is called the A protein. AA amyloidosis is associated with some chronic diseases, such as diabetes, tuberculosis, rheumatoid arthritis, or inflammatory bowel disease. It may also be linked to aging. AA amyloidosis can affect the spleen, liver, kidneys, adrenal glands, and lymph nodes. Lymph nodes are tiny, bean-shaped organs that fight infection.

Hereditary or familial (AF) amyloidosis – Hereditary amyloidosis is rare. It is a specific type of amyloidosis that can be passed down from generation to generation within a family. It may cause issues relating to the central nervous system, carpal tunnel syndrome, and eye abnormalities. The most common subtypes involve a protein called transthyretin (TTR).

Causes

No one knows what causes amyloidosis. There may be more than one cause. Hereditary amyloidosis results from genetic changes that cause the body to make abnormal proteins. Researchers think that as we get older, damage builds up in the body and triggers the disease. This kind of damage may come from the body’s use of oxygen (oxidation) and from free radicals (harmful byproducts formed when cells use energy). Amyloid is also more likely to form in people who have immune system problems. Once amyloid deposits start, they seem to continue building up in the same locations. The heart, kidneys, nervous system, and GI tract are the most commonly affected.

Who is at Risk?

Men – two thirds of people with AL are men.
People over age 50 – even in people with hereditary forms, doctors usually detect amyloid deposits severe enough to cause problems later in life.
Disease affecting the antibody-producing plasma cells in the blood (such as multiple myeloma, malignant lymphoma, benign monoclonal gammopathy, or Waldenström’s macroglobulinemia)
Chronic infectious or inflammatory disease (such as rheumatoid arthritis, inflammatory bowel disease, familial Mediterranean fever, or ankylosing spondylitis)
Long-term dialysis
Inherited genetic changes that affect proteins in the body

Symptoms

Signs and symptoms of amyloidosis may include –

Swelling of your ankles and legs
Severe fatigue and weakness
Shortness of breath
Numbness, tingling or pain in your hands or feet, especially pain in your wrist (carpal tunnel syndrome)
Diarrhea, possibly with blood, or constipation
Feeling full quickly when eating, and significant weight loss
An enlarged tongue
Skin changes, such as thickening or easy bruising, and purplish patches around the eyes
An irregular heartbeat
Difficulty swallowing

Other Complications –

Heart – Because amyloid protein deposits can limit the heart’s ability to fill with blood between beats, even the slightest exertion can cause shortness of breath. If the heart’s electrical system is affected, the heart’s rhythm may become erratic. The heart may also be enlarged and heart murmurs may be present. Congestive heart failure may result.
Kidneys – The feet, ankles, and calves swell when amyloidosis damages the kidneys. The kidneys become small and hard, and kidney failure may result. It is not unusual for a patient to lose 20-25 pounds and develop a distaste for meat, eggs, and other protein-rich foods. Cholesterol elevations that don’t respond to medication and protein in the urine (proteinuria) are common.
Nervous system – Nervous system symptoms often appear in patients with familial amyloidosis. Inflammation and degeneration of the peripheral nerves (peripheral neuropathy) may be present. One of four patients with amyloidosis has carpal tunnel syndrome, a painful disorder that causes numbness or tingling in response to pressure on nerves around the wrist. Amyloidosis that affects nerves to the feet can cause burning or numbness in the toes and soles and eventually weaken the legs. If nerves controlling bowel function are involved, bouts of diarrhea alternate with periods of constipation. If the disease affects nerves that regulate blood pressure, patients may feel dizzy or faint when they stand up suddenly.
Liver and spleen – The most common symptoms are enlargement of these organs. Liver function is not usually affected until quite late in the course of the disease. Protein accumulation in the spleen can increase the risk of rupture of this organ due to trauma.
Gastrointestinal system – The tongue may be inflammed, enlarged, and stiff. Intestinal movement (motility) may be reduced. Absorption of food and other nutrients may be impaired (and may lead to malnutrition), and there may also be bleeding, abdominal pain, constipation, and diarrhea.
Skin – Skin symptoms occur in about half of all cases of primary and secondary amyloidosis and in all cases where there is inflammation or degeneration of the peripheral nerves. Waxy-looking raised bumps (papules) may appear on the face and neck, in the groin, armpits, or anal area, and on the tongue or in the ear canals. Swelling, hemorrhage beneath the skin (purpura), hair loss, and dry mouth may also occur.
Respiratory system – Airways may be obstructed by amyloid deposits in the nasal sinus, larynx and traches (windpipe).

Treatment

Diuretics to relieve swelling caused by fluid retention
Anti-arrhythmics to control heart rhythm
Metoclopramide to help empty food from the stomach
Antibiotics to control bacteria that may cause diarrhea or prevent the body from absorbing nutrients
Anti-inflammatory/immune suppressive therapy to reduce amyloid precursor load
Dialysis, if the kidneys are failing
Peripheral blood stem cell transplantation – During peripheral blood stem cell transplantation, high-dose chemotherapy is administered along with transfusion of stem cells (immature blood cells) to replace damaged bone marrow. These stem cells may come from the patient (autologous transplant) or from a donor (allogeneic transplant). Autologous transplant is the preferred method.
Anti-cancer medication (“antineoplastics”) – Melphalan (Alkeran®), an agent used to treat certain types of cancer, has been prescribed to amyloidosis patients as well. Other types of chemotherapy treatments, like melphalan with high-dose dexamethasone or VAD (vincristine, adriamycin and dexamethasone), are being tested for safety and efficacy in the treatment of amyloidosis. Other medications, including thalidomide, a drug used to treat multiple myeloma, are also being tested for their ability to inhibit the disease.
Corticosteroids -Corticosteroids like prednisone have been prescribed to amyloidosis patients because of their anti-inflammatory effects.
Liver transplantation – For hereditary amyloidosis, one possible therapy may be liver transplantation because the protein that causes this form of amyloidosis is produced in the liver.

Alternative Treatment

DMSO (dimethyl sulfoxide) – DMSO may change the course of amyloidosis if treatment is started early. However, there is not much scientific support for this claim.

Germanium – Studies suggests that germanium compounds may prevent amyloidosis. Results can only be considered preliminary at this time.

Resveratrol – Preliminary data suggests that resveratrol may play a role in the prevention of amyloidosis. High quality clinical research is needed to better understand this relationship.

Omega-3s – These are also essential dietary elements when suffering from amyloidosis. Commonly found in many types of meat, these beneficial fatty acids, particularly the type found in fish oil, can significantly protect your heart and vascular system, ensuring that your circulatory system remains healthy and functioning properly, while also reducing the chances of coronary heart disease and atherosclerosis, which can quicken the complications of amyloidosis in the cardiovascular system.

Vitamin C – Study suggested that high doses of vitamin C may help the body break down amyloid and prevent amyloidosis from worsening, but there is no evidence this works in humans.

Bromelain – An enzyme derived from pineapple, fights inflammation and may help break down amyloid deposits in kidney tissue, though evidence is slight. Bromelain is often combined with turmeric, which strengthens its effects. Bromelain can interact with certain medications including some antibiotics.

Glutathione is an antioxidant produced by the body. Low levels may be associated with higher levels of beta2-microglobulin in people on dialysis with or without amyloidosis.

Quercetin is an antioxidant with anti-inflammatory properties. It has not been studied for amyloidosis.

Gingko extract also contains flavonoids. It has been suggested as a treatment for Alzheimer’s disease.

Reference –

http://www-sop.inria.fr/axis/cost282/kelsi04/Brito/Brito1.pdf

http://rstb.royalsocietypublishing.org/content/356/1406/203

https://www.ucl.ac.uk/amyloidosis/nac/amyloidosis-overview

http://www.msdmanuals.com/professional/endocrine-and-metabolic-disorders/amyloidosis/amyloidosis

https://my.clevelandclinic.org/health/diseases_conditions/hic-amyloidosis

http://patient.info/doctor/amyloidosis-pro

http://www.amyloidosissupport.org/AmyloidAware_Booklet.pdf

http://www.webmd.com/a-to-z-guides/amyloidosis-symptoms-causes-treatments

http://www.cancer.net/cancer-types/amyloidosis