Amyloid light chain (AL) amyloidosis

What is AL amyloidosis?

In AL amyloidosis, amyloid protein fibre deposits build up in tissues and organs throughout the body (e.g., heart, kidneys, liver, soft tissues, nervous and digestive systems). All patients have a different amyloid protein fibre deposition pattern. These fibres gradually damage tissues and organs which can cause renal and kidney complications and many different symptoms such as:

• Shortness of breath, dizziness, fatigue
• Fluid retention (edema) causing swollen legs/feet
• Bruising (e.g., around the eyes)
• Skin rash, nail changes
• Swollen tongue (macroglossia)
• Swelling of both shoulder joints
• Peripheral neuropathy: Pain, numbness, and tingling in the extremities (e.g., carpal tunnel syndrome)
• Digestive problems: Diarrhea, nausea, weight loss

Are AL amyloidosis and myeloma related?

People may have AL amyloidosis on its own or with myeloma. While some people with myeloma may also have, or develop, AL amyloidosis, it is rare for people with AL amyloidosis to develop myeloma.

Both AL amyloidosis and myeloma result from abnormal plasma cells, a type of white blood cell produced in the bone marrow. Healthy plasma cells produce a variety of antibodies (proteins known as immunoglobulins) that circulate in the blood and are critical to the body’s immune system function. In AL amyloidosis, abnormal plasma cells, overproduce unstable immunoglobulin light chain fragments that circulate in the blood and link together to form amyloid protein fibres. Whereas for myeloma, abnormal plasma cells produce abnormal non-functional clones of monoclonal antibodies, also commonly referred to as M-protein, monoclonal protein, paraprotein, myeloma protein or M-spike.

What are the treatments for AL amyloidosis?

Treatments for AL amyloidosis are similar to those for multiple myeloma. Newly diagnosed AL amyloidosis patients may benefit from:

• treatment with a combination of drugs called CyBorD (cyclophosphamide, bortezomib [Velcade], dexamethasone);
• daratumumab (Darzalex) in combination with CyBorD (may not be available in all provinces/territories);
• high-dose therapy and autologous stem cell transplantation.

At relapse, new amyloid protein fibre deposits build-up in tissues and/or organs. Treatment should be individualized based on previous therapies and potential side effects. Relapsed AL amyloidosis may be treated with the same combination of drugs as before or a different combination of drugs. Moreover, supportive care treatments can be given alongside AL amyloidosis treatment to control or alleviate the symptoms and complications of the disease, as well as any side effects that may result from the treatment itself.

Treatment can kill abnormal plasma cells to prevent new deposits from forming; allow for effective disease control, symptom reduction, and improved quality of life; and result in periods of remission where the disease is not active. Thus far, a cure for AL amyloidosis has not yet been found.

*This section only concerns amyloid light chain (AL) amyloidosis. Click here to learn more about other types of amyloidosis.