Amyloidosis: AL (Light Chain)

Overview

How amyloid fibrils are formed.
Formation of Amyloid Fibrils.

What is amyloidosis?

Amyloidosis (am-uh-loy-doh-sis) is a protein disorder. In this disease, proteins change shape (misfold), then bind together and form amyloid fibrils which deposit in organs. As amyloid fibrils build up, the tissues and organs may not work as well as they should.

Our bodies make several proteins that can cause amyloidosis. To choose the right treatment, it is very important to know the exact protein that is causing the disease. The two most common types are light chain (AL) and transthyretin (ATTR) amyloidosis.

What is AL (light chain) amyloidosis?

Light chains are pieces of antibodies made by white blood cells, specifically plasma cells, in the bone marrow. In AL amyloidosis, a group of plasma cells make too many light chains, which misfold and bind together to form amyloid fibrils. The fibrils are then deposited in organs. The most common organs affected are the heart and kidneys. Light chain amyloidosis can also affect the stomach, large intestine, liver, nerves, skin and can cause an enlarged tongue. The condition can cause problems with one or more parts of the body.

Symptoms and Causes

What are the signs and symptoms of AL amyloidosis?

AL amyloidosis can affect many organs, resulting in the following signs and symptoms:

Symptoms indicating the arms are affected include:

  • Carpal tunnel syndrome
  • Numbness, burning and/or tingling (peripheral neuropathy)
  • Weak fingernails

Symptoms indicating the legs are affected include:

  • Swelling of the feet or legs
  • Leg weakness
  • Weak toenails

Symptoms indicating the head and neck are affected include:

  • Lightheadedness upon standing
  • Purple color on the eyelids and/or around the eyes
  • Enlarged tongue

Symptoms indicating the heart and lungs are affected include:

  • Shortness of breath
  • Palpitations (arrhythmias)
  • Chest pain
  • Fatigue

Symptoms indicating the stomach or intestines are affected include:

Symptoms indicating the kidney and bladder are affected include:

  • Excessive bubbles in the urine
  • Urinating less
  • Getting up at night to urinate

Other signs and symptoms:

  • Bruising or bleeding easily
  • Purple color in skin folds

AL Amyloidosis Symptoms Chart

Diagnosis and Tests

How is AL amyloidosis diagnosed?

Many tests can be performed to diagnosis amyloidosis. A biopsy (the removal of cells or tissue) of the affected organ(s) is the most useful test. A pathologist will examine the tissue under a microscope and perform special tests to identify the exact protein that is causing the amyloidosis.

Your doctor will talk to you about the biopsy/biopsies you need, which may include:

  • Bone marrow biopsy: A small sample of bone marrow is removed from inside the bone. All patients with AL amyloidosis need a bone marrow biopsy.
  • Kidney biopsy: An ultrasound is used to help guide a needle into the kidney. A few small pieces of tissue are removed.
  • Heart biopsy: A small, thin, hollow tube (catheter) is guided to the heart through a vein in your neck. A few small pieces of the heart muscle are removed.
  • Fat pad biopsy: A small piece of fat tissue is removed from your abdomen.

In addition to a biopsy, you may need other tests to find out how well your organs are working:

  • Blood samples to check the kidneys, heart, liver and the amount of light chains in your blood.
  • A 24-hour urine collection (done at home and returned to your doctor) to see if your kidneys are affected.
  • Electrocardiogram (EKG) and echocardiogram (ultrasound of the heart).
  • A cardiac MRI or a cardiac nuclear scan (technetium pyrophosphate scan) may be done to see if your heart is affected.

Management and Treatment

How is AL amyloidosis treated?

A doctor who specializes in blood disorders (hematologist) will create a treatment plan for you.

Treatments for patients with AL amyloidosis include various medications:

Chemotherapy drugs

Immunotherapy drugs

Steroid medications

Most patients take one or two chemotherapy drugs plus steroid medication. The drugs work together to destroy the plasma cells that make the light chain proteins. Your doctor may also talk to you about whether you may benefit from a bone marrow/stem cell transplant.

Medications can stop or slow the progression of AL amyloidosis but cannot remove the fibrils already in the body. A monoclonal antibody CAEL-101, designed to remove the amyloid deposits in the affected organs, is being tested in clinical trials.

Your treatment team will likely include:

Cardiologist: A doctor that specializes in the heart.

Gastroenterologist: A doctor who specializes in the gastrointestinal tract.

Hematologist: A doctor that specializes in blood problems.

Nephrologist: A doctor that specializes in the kidneys.

Neurologist: A doctor that specializes in the nerves.

Outlook / Prognosis

What is the outlook (prognosis) for persons with AL amyloidosis?

Amyloidosis is a long term (chronic) disease that can be controlled. Early diagnosis and treatment are the keys to managing the disease before it becomes advanced.

Resources

Cleveland Clinic Amyloidosis Center

Cleveland Clinic Center for Personalized Genetic Healthcare

  • 216.636.1768

Amyloid Foundation

Amyloidosis Support Groups

Amyloidosis Research Consortium

Cleveland Clinic Appointments: 866.320.4573

Cleveland Clinic Cancer Answer Line: 866.223.8100

Glossary of Terms

Amyloid Fibril: A rigid stack of amyloid proteins that builds up in organs.

Amyloidosis: A disease caused by a buildup of abnormally shaped proteins (amyloid proteins) in organs.

Stem cell transplant: A process in which the cells that make blood (stem cells) are removed before chemotherapy and replaced after treatment.

Biopsy: A small piece of tissue that is removed and examined under a microscope.

Cardiac magnetic resonance imaging (MRI): A scan that creates detailed pictures of the heart and shows how well it is working.

Chemotherapy: Medications used to get rid of abnormal cells. Chemotherapy can include one or more medications.

Echocardiogram: An ultrasound of the heart to show how well the heart is working.

Electrocardiography (EKG): A recording of the heart’s electrical activity.

Light chain: A piece of an antibody protein that is made by plasma cells in the bone marrow.

Proteins: Large molecules that control the structure and function of the body’s tissues and organs.

Last reviewed by a Cleveland Clinic medical professional on 06/02/2020.

References

  • Cleveland Clinic Amyloidosis Center. (http://clevelandclinic.org/amyloidosiscenter) Accessed 6/2/2020.
  • Donnelly JP, Hanna M. Cardiac amyloidosis: An update on diagnosis and treatment. CCJM 2017;84(12 suppl 3):12-26. Accessed 6/2/2020.
  • National Institute of Diabetes and Digestive and Kidney Diseases. Amyloidosis and Kidney Disease. (https://www.niddk.nih.gov/health-information/kidney-disease/amyloidosis) Accessed 6/2/2020.
  • Amyloidosis Foundation. Amyloidosis Facts. (http://amyloidosis.org/facts/) Accessed 6/2/2020.
  • National Organization for Rare Disorders. Amyloidosis. (https://rarediseases.org/rare-diseases/amyloidosis/) Accessed 6/2/2020.

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