AL amyloidosis
Encyclopedia
Amyloid Light-chain amyloidosis, primary systemic amyloidosis (PSA) or just primary amyloidosis is the most common form of systemic
amyloidosis
in the US. The disease is caused when a person's antibody
-producing cells do not function properly and produce abnormal protein fibers made of components of antibodies called light chains
. These light chains come together to form amyloid deposits in different organs which can cause serious damage to these organs. Abnormal light chains in blood and urine are sometimes referred to as "M-protein" or "Bence Jones protein
".
In addition to kidneys, AL amyloidosis may effect the heart, peripheral nervous system, gastrointestinal tract, blood, lungs and skin. Heart compliciations, which afflict more than a third of AL patients, include heart failure and irregular heart beat. Other symptoms can include stroke, gastrointestinal disorders, enlarged liver, diminished spleen function, diminished function of the adrenal and other endocrine glands, skin color change or growths, lung problems, bleeding and bruising problems, fatigue and weight loss.
and Waldenström's macroglobulinemia. Some sources suggest that 10% to 15% of patients with multiple myeloma may develop overt AL amyloidosis.
Other treatments can involve application of chemotherapy
similar to that used in multiple myeloma. A combination of bortezomib
and dexamethasone
has been proposed, as has melphalan
and dexamethasone.
Systemic disease
Life-threatening disease redirects here.A systemic disease is one that affects a number of organs and tissues, or affects the body as a whole. Although most medical conditions will eventually involve multiple organs in advanced stage Life-threatening disease redirects here.A systemic disease is one...
amyloidosis
Amyloidosis
In medicine, amyloidosis refers to a variety of conditions whereby the body produces "bad proteins", denoted as amyloid proteins, which are abnormally deposited in organs and/or tissues and cause harm. A protein is described as being amyloid if, due to an alteration in its secondary structure, it...
in the US. The disease is caused when a person's antibody
Antibody
An antibody, also known as an immunoglobulin, is a large Y-shaped protein used by the immune system to identify and neutralize foreign objects such as bacteria and viruses. The antibody recognizes a unique part of the foreign target, termed an antigen...
-producing cells do not function properly and produce abnormal protein fibers made of components of antibodies called light chains
Immunoglobulin light chain
]The immunoglobulin light chain is the small polypeptide subunit of an antibody .A typical antibody is composed of two immunoglobulin heavy chains and two Ig light chains.-In humans:...
. These light chains come together to form amyloid deposits in different organs which can cause serious damage to these organs. Abnormal light chains in blood and urine are sometimes referred to as "M-protein" or "Bence Jones protein
Bence Jones protein
A Bence Jones protein is a monoclonal globulin protein found in the blood or urine, with a molecular weight of 22-24 kDa.Finding this protein is often suggestive of multiple myeloma or Waldenstrom's macroglobulinemia....
".
Signs and symptoms
AL amyloidosis can affect and wide range of organs, and consequently present with a range of symptoms. Kidney complications are the most commonly cited results of AL amyloidosis. Symptoms of kidney disease and renal failure can include fluid retention, swelling, and shortness of breath.In addition to kidneys, AL amyloidosis may effect the heart, peripheral nervous system, gastrointestinal tract, blood, lungs and skin. Heart compliciations, which afflict more than a third of AL patients, include heart failure and irregular heart beat. Other symptoms can include stroke, gastrointestinal disorders, enlarged liver, diminished spleen function, diminished function of the adrenal and other endocrine glands, skin color change or growths, lung problems, bleeding and bruising problems, fatigue and weight loss.
Causes
AL amyloidosis can occur spontaneously, however, it is often associated with other blood disorders, such as multiple myelomaMultiple myeloma
Multiple myeloma , also known as plasma cell myeloma or Kahler's disease , is a cancer of plasma cells, a type of white blood cell normally responsible for the production of antibodies...
and Waldenström's macroglobulinemia. Some sources suggest that 10% to 15% of patients with multiple myeloma may develop overt AL amyloidosis.
Diagnosis
Both blood and the urine can be tested for the light chains, which may form amyloid deposits, causing disease. However, the diagnosis requires a sample of an effected organ.Treatment
The most effective treatment is autologous bone marrow transplants with stem cell rescues. However many patients are too weak to tolerate this approach.Other treatments can involve application of chemotherapy
Chemotherapy
Chemotherapy is the treatment of cancer with an antineoplastic drug or with a combination of such drugs into a standardized treatment regimen....
similar to that used in multiple myeloma. A combination of bortezomib
Bortezomib
Bortezomib is the first therapeutic proteasome inhibitor to be tested in humans. It is approved in the U.S. for treating relapsed multiple myeloma and mantle cell lymphoma...
and dexamethasone
Dexamethasone
Dexamethasone is a potent synthetic member of the glucocorticoid class of steroid drugs. It acts as an anti-inflammatory and immunosuppressant...
has been proposed, as has melphalan
Melphalan
Melphalan hydrochloride is a chemotherapy drug belonging to the class of nitrogen mustard alkylating agents.An alkylating agent adds an alkyl group to DNA...
and dexamethasone.