Waldenström's macroglobulinemia

Medical quality assurance by Dr. Albrecht Nonnenmacher, MD at November 14, 2016
StartWaldenström's macroglobulinemia

Waldenström's macroglobulinemia is a type of cancer. This condition was named after the oncologist, Jan Waldenström, who identified it in 1944. Fortunately, this form of cancer is distinctive because it is rather treatable. 

Contents

Definition & Facts

Technically, Waldenström's macroglobulinemia is a unique form of non-Hodgkin's lymphoma. Like all other lymphomas, this condition is a type of cancer that causes white blood cells to multiply at an overwhelming rate.

It is distinctive from the more general type of lymphoma because it causes proliferation of immunoglobulin M, an antibody that helps to thicken the blood. Waldenström's macroglobulinemia is also unusual because it is a type of indolent lymphoma.

This means that it is a cancer that progresses very slowly and does not spread. Waldenström's macroglobulinemia has a five-year survival rate of 78 percent, and only about 1,500 cases are diagnosed each year.

Symptoms & Complaints

Waldenström's macroglobulinemia does not always cause any noticeable symptoms at first. As time progresses, more subtle symptoms will become noticeable. Patients with Waldenström's macroglobulinemia often feel very weak and tired because they are not getting enough oxygen. This happens because the overgrowth of white blood cells crowds out healthy red blood cells.

General symptoms of lymphomas, such as fever, weight loss, enlarged lymph nodes, and night sweats, also occurs. Waldenström's macroglobulinemia tends to cause hyperviscosity, which is excessively thickened blood, because of the extreme levels of immunoglobulin. This leads to poor circulation, especially in the brain, and causes headaches, slurred speech, confusion, and even stroke-like symptoms.

The poor circulation caused by Waldenström's macroglobulinemia also tends to cause pain and feelings of cold in the extremities. It can lead to heart problems over time, so some patients who have had Waldenström's macroglobulinemia start to experienced congestive heart failure.

Patients may also experience vision issues or nosebleeds due to thickened blood. In some cases, patients with Waldenström's macroglobulinemia experience liver, spleen, intestinal and kidney problems because of the buildup of the antibodies. This can cause a swollen abdomen to appear, and they frequently suffer from digestive issues and abnormal bowel movements

Causes

There are a few different causes of Waldenström's macroglobulinemia, but it is mostly caused by genetic mutations. 90 percent of all Waldenström's macroglobulinemia have a mutation in the MYD88 gene while 27 percent of patients have a mutation in the CXCR4 gene. Both of these genes are responsible for coding the proteins that regulate immune system functions.

When the gene is mutated, it tends to cause excessive production of white B cells and immunoglobulin antibodies. The genetic mutations that cause Waldenström's macroglobulinemia are mostly spontaneous. At some point, a damaged cell may be produced randomly that results in cancer. However, there is some evidence that a susceptibility towards Waldenström's macroglobulinemia may be hereditary.

The genetic risk factors for Waldenström's macroglobulinemia are more commonly found in people with European ancestry. Other risk factors for Waldenström's macroglobulinemia include being infected with hepatitis C, being male, being over the age of 50, or already having another autoimmune disease like Sjögren's syndrome.

Diagnosis & Tests

Waldenström's macroglobulinemia is normally not diagnosed immediately because the symptoms are so mild that it is not noticeable at first. Therefore, a basic physical examination and medical history is generally not enough to diagnose the condition. The typical diagnosis process happens when a patient goes to a doctor complaining of general feelings of malaise and weakness. This normally leads to a routine blood test that can reveal abnormally high white blood cell counts or unusually low red blood cell counts. However, many conditions can cause these symptoms, so it is necessary to run more tests.

A complete blood cell count is a more in depth examination of a blood sample that can reveal abnormalities. Another test, called a quantitative immunoglobulins test, can show the presence of unusually high antibody levels. If this is discovered, an immunoelectrophoresis test can determine if the unusually high levels are caused by immunoglobulin M.

All of these tests can be done with a simple blood sample, but if Waldenström's macroglobulinemia is suspected, than it will be necessary to do a bone marrow biopsy. After removing bone marrow from the pelvis, a lab can test it to see if lymphoma cells are present. If at least 10 percent of the cells in the sample are lymphoma cells, than the diagnosis will be confirmed.

Treatment & Therapy

If absolutely no symptoms are present, doctors may just monitor the patient to see if more invasive treatment is needed. Waldenström's macroglobulinemia progresses very slowly, so harmful radiation may not be advised at this stage. Instead, first line treatment focuses on reducing B-cell and immunoglobulin M levels while boosting red blood cell levels.

Corticosteroids, rituximab, and ibrutinib are all often prescribed at this stage. Rituximab and ibrutinib are types of immunotherapy drugs that stimulate the immune system to destroy the cancerous lymphoma cells. If the blood is dangerously viscous, patients can be hooked up to a plasmapheresis machine that separates out the immunoglobulins and then returns the filtered blood to the patient's body.

Bone marrow transplants or stem cell therapy can be a viable choice in some instances. If the cancer progresses, radiation therapy or chemotherapy may be recommended. Though these treatments have unpleasant side effects, they can help to halt the overgrowth of B cells. Treatment plans will vary greatly depending on a patient's unique state of health.

Prevention & Prophylaxis

Unfortunately, no proven way of preventing Waldenström's macroglobulinemia has been found. Patients who already have a family member with the condition may benefit from regular screenings and blood tests because they are more likely to develop Waldenström's macroglobulinemia.

Prompt diagnosis is extremely important because it allows a patient to begin treatment before the cancer progresses. Since Waldenström's macroglobulinemia has also been linked to hepatitis C infection, it is wise to practice safe sex and avoid exposure to infected blood.