Multiple myeloma and AL amyloidosis are two different diagnoses, but they may co-exist. Outlook will depend on the stage of myeloma and the organs affected.
About 10 to 15% of people with multiple myeloma develop a condition called amyloid light-chain (AL) amyloidosis. Having both conditions may affect someone’s outlook and cause additional complications.
Multiple myeloma and AL amyloidosis are closely related and frequently diagnosed together.
Multiple myeloma and plasma cells
Multiple myeloma, also called myeloma, is a rare blood cancer that involves abnormal growth of plasma cells found in the bone marrow.
Healthy plasma cells create Y-shaped proteins called antibodies that help your body destroy foreign invaders. These proteins bind to areas on the surface of germs like a lock and key. This binding tags the invader so that other immune cells know to attack it.
In people with multiple myeloma, cancerous plasma cells make atypical antibodies called monoclonal proteins (M-proteins). M-proteins can crowd out healthy blood cells — not only invaders — and cause symptoms like fatigue and frequent infection, among others.
AL amyloidosis and light chains
Antibodies are made up of two molecules called heavy chains and two molecules called light chains.
AL amyloidosis, also known as primary amyloidosis, develops when cancerous plasma cells secrete too many misshapen light chains. These light chains build up in your organs and become deposits called amyloid.
The development of AL amyloidosis is associated with a better outlook in people with myeloma, especially when light chains build up in the heart.
Amyloid can cause organ dysfunction, enlargement, and failure. It can develop in multiple organs or just one. According to a
| Organ | Percent of cases |
|---|---|
| heart | 75% |
| kidneys | 65% |
| liver | 15% |
| soft tissue | 15% |
| peripheral or autonomic nervous system | 10% |
| gastrointestinal tract | 5% |
Symptoms of multiple myeloma are typically referred to by the acronym CRAB, which stands for:
- C: elevated calcium
- R: renal (kidney) failure
- A: anemia, or a low blood cell count
- B: bone damage
Symptoms of AL amyloidosis are broad, depending on which organs are affected. Many of the symptoms of AL amyloidosis and multiple myeloma overlap.
In a
| AL amyloidosis | Early diagnosis (<6 months) | Delayed diagnosis (≥6 months) |
|---|---|---|
| fatigue | 70.2% | 86.8% |
| shortness of breath | 52.7% | 71.8% |
| swelling in the ankles or legs | 61.1% | 67.9% |
| dizziness when standing | 41.1% | 57.9% |
| loss of appetite | 38.7% | 56.7% |
| alternating constipation and diarrhea | 27.8% | 32.6% |
| unintentional weight loss | 35.1% | 41.3% |
| an enlarged tongue | 13.8% | 23.1% |
| numbness of the arms and legs | 20.0% | 47.9% |
| purple color around the eyes | 18.3% | 27.3% |
According to a
In some people, the molecular characteristics of these light chains cause them to clump together and form structures called fibrils, which deposit in the tissues. The deposited fibrils destroy an organ’s usual form and function.
Affected organs can include the:
- heart
- liver
- kidneys
- nervous system
- gastrointestinal tract
A
AL amyloidosis and multiple myeloma share some genetic risk factors. The primary risk factor for AL amyloidosis is age. According to 2017 research, the
Diagnosis and treatment of AL amyloidosis is often delayed because it causes nonspecific symptoms.
A 2021 research review suggests the median time from the beginning of symptoms to diagnosis is 6 to 12 months, with the average person visiting 3 to 4 doctors before their diagnosis is confirmed. Diagnosis is usually most straightforward in people with kidney symptoms.
For an AL amyloidosis diagnosis, doctors need to take a tissue sample to find evidence of amyloid buildup in your organs.
If AL amyloidosis is suspected, a doctor will first take a small sample with a needle from an easily accessible tissue, like the fat under your skin. This procedure is called fat aspiration. Fat aspiration combined with a bone marrow biopsy can diagnose AL amyloidosis in about 90% of people.
Special staining will be applied to your tissue sample in a lab to look for signs of amyloid. The most commonly used stain is called Congo red. Additional lab tests will be done to analyze what type of protein is building up.
Three pillars for improving the survival of AL amyloidosis include:
- early detection
- anti-plasma cell therapy
- supportive care
The primary treatment for multiple myeloma with AL amyloidosis is targeting the underlying cancerous plasma cells.
This might include:
- high dose chemotherapy followed by an autologous stem cell transplant, where stem cells are collected from your blood and retransplanted after chemotherapy
- the medication daratumumab (Darzalex) with bortezomib (Velcade), cyclophosphamide (Cytoxan), and dexamethasone (Decadron) in people not eligible for bone transplant
- diuretics for managing congestive heart failure or nephrotic syndrome
- drugs like midodrine (Proamatine) or droxidopa (Northera) to treat neuropathy
- organ transplants
Targeting amyloid deposits using monoclonal antibodies is still under clinical trials, and has not been approved yet.
A
According to
The
The median overall survival for people with myeloma with AL amyloidosis is
But a number of different factors play into these estimates. For example, the stage of cancer at diagnosis and the organs affected by AL amyloidosis can change the outlook.
Multiple myeloma is a cancer that develops in plasma cells in the bone marrow. Some people with multiple myeloma also develop AL amyloidosis. AL amyloidosis occurs when proteins called light chains build up in an organ or multiple organs.