A comparison of multiple myeloma and amyloidosis

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The plasma cells of the bone marrow are an important part of the immune system. If they become cancerous and grow out of control, doctors call this multiple myeloma. These plasma cells make abnormal antibodies called M-protein or monoclonal paraprotein, which can damage organs.

Learn more about multiple myeloma here.

Amyloidosis is a group of rare and serious conditions that also involve the plasma cells. Primary amyloidosis, or AL (light chain) amyloidosis is the most common type. Other forms of amyloidosis are unrelated.

AL amyloidosis is closely related to multiple myeloma. It involves the build-up of abnormal light-chain proteins that form amyloid deposits. These deposits can damage organs and tissues throughout the body and make it difficult for them to function properly. Without treatment, amyloidosis can lead to organ failure.

Learn more about amyloidosis, including information about risk factors here.

Differences

Multiple myeloma and amyloidosis share a common cause: the presence of malignant plasma cells in the bone marrow.

However, in multiple myeloma, the primary issue is an abnormal growth of plasma cells that accumulate in the bone marrow. This buildup of plasma cells can then cause anemia and bone damage.

Conversely, in amyloidosis, plasma cells do not accumulate. Instead, they create abnormal light chains, which lead to deposits. This can happen independently of any tumors being present. Doctors might consider amyloidosis a complication of multiple myeloma.

There is an overlap between the two conditions, and often doctors diagnose people with both.

Multiple myeloma

Doctors do not know exactly what causes multiple myeloma. However, changes or mutations in a person’s genetic material can trigger plasma cells to become malignant.

Some mutations in DNA may activate oncogenes — genes that promote cell growth. Other mutations may turn off tumor suppressor genes, which are genes that can slow down cell growth or cause cell death when appropriate.

Myeloma cells may also have chromosomal abnormalities. Typically, DNA fits into 46 chromosomes. Cancer cells can either have additional chromosomes or parts; sometimes the whole chromosome is missing.

For many people with this condition, parts of chromosome number 17 are missing in the myeloma cells, and this absence makes the myeloma more aggressive.

Amyloidosis

Sometimes, multiple myeloma may lead to amyloidosis.

Additionally, inflammatory diseases can cause secondary amyloidosis, and genetics can play a role in the development of hereditary amyloidosis.

Multiple myeloma

Some individuals with multiple myeloma have no symptoms, while others may experience the following:

• bone pain
• bone weakness and fractures
• spinal cord compression
• nerve damage
• anemia
• low white blood cells
• low platelet counts
• high levels of calcium in the blood

Amyloidosis

An individual with amyloidosis may have some of the same symptoms, such as nerve damage.

However, they can also have issues, including:

• Heart problems: The heart can become larger and weaker, leading to fluid buildup in the lungs and shortness of breath.
• Enlarged liver: A person may be able to feel the liver below the right ribs.
• Enlarged tongue: If amyloid deposits build up in the tongue, it can increase in size leading to problems swallowing and breathing during sleep.
• Skin changes: People may bruise easily and bleed into the skin surrounding the eyes— known as raccoon eyes.
• Carpal tunnel syndrome: People may notice numbness and weakness in their hands.

Doctors diagnose multiple myeloma and amyloidosis by considering their symptoms and ordering various tests. These may include:

• Complete blood count. This test measures the level of different cells and platelets in the blood.
• Blood chemistry test. These can include checking levels of creatinine, albumin, and calcium. Creatinine shows kidney health. In multiple myeloma, doctors expect to see low albumin and may see high calcium in advanced myeloma.
• Urine test. This test measures the presence or levels of certain proteins in urine
• Quantitative immunoglobulin tests. These measure levels of antibodies in the blood.
• Electrophoresis. There are many types of this test. This test can show what types of monoclonal and other antibodies are present in the blood.
• Serum-free light chains. This test can measure the amount of light chains in the blood. This is particularly useful for diagnosing amyloidosis.
• Biopsy. Two main types include bone marrow biopsy and fine-needle aspiration biopsy.
• Imaging. These can include CT scans, bone x-rays, MRIs, and PET scans.
• Echocardiogram. This test assesses heart health, which can be important as amyloidosis often affects the heart’s structure.

Multiple myeloma

A doctor may diagnose multiple myeloma after confirming a person has a plasma cell tumor, at least 10% plasma cells in their bone marrow, and one of the following:

• elevated blood calcium level
• poor kidney function
• anemia
• holes in the bones from tumors
• an increase in one type of light chain with a ratio greater than 100 in the blood
• at least 60% of plasma cells in the bone marrow

Amyloidosis

Diagnosis of amyloidosis usually requires the above tests as well as other tests that look for the buildup of abnormal proteins in the body. These can include:

• fat pad biopsy,
• a kidney biopsy,
• heart biopsy,
• and special cardiac imaging.

Doctors often treat individuals with multiple myeloma or primary amyloidosis with a combination of two or three chemotherapy agents.

The choice of drugs depends on the person’s health and whether the doctor plans on performing a stem cell transplant. In a stem cell transplant, an individual receives chemotherapy to kill abnormal bone marrow cells and then receives healthy blood-forming stem cells to replace them.

The doctor may also recommend treatment for bone disease, such as bisphosphonates, alongside chemotherapy. The doctor may recommend radiation therapy if individuals continue to have bone problems.

Supportive treatments such as antibiotics, transfusions to treat low blood cell counts, and intravenous immunoglobulins can be beneficial.

Learn about stem cells here.

Individuals with multiple myeloma have a 5-year relative survival rate of approximately 55%. This means someone with the condition is 55% as likely to live at least 5 years as someone who does not.

This figure comes from people diagnosed with multiple myeloma from 2011 to 2017. Recent advances over the past several years have led to an improvement in this number.

However, a person’s outlook depends on their overall health, age, kidney function, the levels of certain substances in their blood, and the characteristics of the tumor.

If an individual has amyloidosis, their prognosis depends on the type of amyloidosis they have and how they respond to treatments. Left untreated, it can be fatal. An individual’s outlook depends on organ involvement because if amyloidosis affects the heart, it can significantly decrease the likelihood of survival.

Multiple myeloma and amyloidosis are two conditions that stem from abnormalities in the plasma cells of the bone marrow. Multiple myeloma causes an overgrowth of abnormal cells, while amyloidosis results in the secretion of abnormal proteins that can build up and damage organs.

Doctors use a similar approach to diagnose both conditions, including blood analysis, imaging studies, and bone marrow biopsies. Treatment for the conditions typically involves chemotherapy and may also involve stem cell transplant.

People with multiple myeloma have a 5-year relative survival rate of approximately 55%. However, if someone has amyloidosis, their outlook depends on how much organ damage they have sustained.