Waldenstrom Macroglobulinemia

Waldenstrom macroglobulinemia is a rare slow-growing cancer that affects your blood cells. It’s a type of non-Hodgkin’s lymphoma. (Healthcare providers may refer to this condition by the initials WM or the name lymphoplasmacytic lymphoma). WM happens when genetic mutations change certain blood cells, setting up a chain reaction of medical conditions that may be life-threatening. Providers can’t cure this condition, but they do have treatments that ease and sometimes eliminate its symptoms.

Is Waldenstrom macroglobulinemia a common disease?

No, it’s not common. It’s a very rare disease that affects about 5 people per 1 million in the United States. Healthcare providers diagnose an estimated 1,000 to 1,500 new cases each year. Waldenstrom macroglobulinemia typically affects people aged 65 and older. Men and people assigned male at birth are more likely to develop WM than women or people assigned female at birth. WM is more common in people who are white than in people in other ethnic groups.

How does Waldenstrom macroglobulinemia affect my body?

Waldenstrom macroglobulinemia starts in white blood cells called B-lymphocytes or B-cells that are under development in your bone marrow. Your bone marrow is the spongy center of your bones. It produces stem cells that eventually become red blood cells, white blood cells and platelets.

In WM, B-cells turn into abnormal cells called lymphoplasmacytoid cells. This happens when two genes in certain proteins that manage B-cell activity mutate or change. When these genes mutate, they turn a single normal B-cell into an abnormal cell that reproduces more cells. The abnormal cells make unusually large amounts of an antibody protein known as immunoglobulin M (IgM or M protein).

M protein thickens your blood, turning it from free-flowing fluid into a syrup-like liquid. This is hyperviscosity syndrome. This is a very rare condition unique to Waldenstrom macroglobulinemia. The thickened blood doesn’t flow easily through your body’s tiny blood vessels. Sometimes blood vessels tear, causing your nose, gums or the retinas in your eyes to seep (ooze) blood.

At the same time, your bone marrow continues to fill up with abnormal cells. Normally, your B-cells mature and move into your bloodstream, where they eventually die and are replaced with more healthy B-cells. In WM, abnormal cells stay in your bone marrow, where they keep multiplying and do not die. Just like people piling into a subway car until there’s no room for any new passengers, abnormal blood cells crowd your bone marrow, leaving no space for normal blood cells to develop. Here’s what may happen then:

• You may develop anemia because your bone marrow can’t produce the normal amount of red blood cells. Anemia is a common symptom of Waldenstrom macroglobulinemia.
• You may have more infections than usual because you don’t have the normal amount of neutrophils, which are infection-fighting white blood cells. Providers may call this neutropenia.
• You may bleed and bruise more easily because you don’t have the normal number of platelets that help blood clot. Providers may call this thrombocytopenia.

Left untreated, WM can be life-threatening. It may also cause complications including:

• Amyloidosis: This condition happens when abnormal proteins build up in organs including your heart, lungs and kidneys.
• Cryoglobulinemia: This condition happens when certain blood proteins that react to cold conditions gather in clumps in your hands and feet, causing pain and turning your hands and feet blue or white.