Multiple myeloma, amyloidosis, and other plasma cell disorders are often diagnosed based on results from a combination of tests, patient symptoms, and a physical exam. Many tests are looking for the presence of M proteins, which are the abnormal antibody created by the cancerous plasma cells present in multiple myeloma. The lab work and procedures that are commonly performed in plasma cell disorder assessment is outlined below. These tests may also be performed as part of routine follow-up after receiving a myeloma diagnosis to determine how well treatment is working and if any changes should be made to a patient’s care.
Complete blood counts: The complete blood count (CBC) is a blood test measuring the complete levels of red cells, white cells, and platelets in the blood. This test can help understand if or how much the abnormal cells are impacting normal blood cell production. For example, low levels of red blood cells are a sign of anemia, which can be a common indicator that there is an issue with the plasma cells.
Serum Protein Electrophoresis and Serum Immunofixation: These tests measure the antibodies in the blood and can identify both the presence of multiple myeloma cells as well as the type of abnormal antibody present, such as an M protein.
Beta-2 Microglobulin: The Beta-2 Microglobulin is a protein made of myeloma cells and is a marker of myeloma activity. While the protein doesn’t cause symptoms; it can be used to determine a myeloma diagnosis and prognosis. Higher levels of this protein may indicate a more advanced stage of myeloma.
Electrolytes: Electrolytes are present in the blood, urine, tissue, and other bodily fluids and help balance water levels in the body. Because plasma cell disorders can affect kidney function, checking electrolyte levels can help determine if a person’s kidneys are working properly and if they are currently affected.
Assessment of organ function: Additional blood tests may be performed to determine how well other organs in the body are functioning. Plasma cell disorders most often affects the kidneys but can also cause problems for other organs. Testing for overall function can determine the presence of the disease, as well as how progressive the disease is.
24-hour urine collection: This test is a complete collection of the urine produced over a 24-hour period to assess the presence of M proteins, which are called Bence Jones proteins when they’re detected in the urine. By collecting and examining the urine in this way, a full picture of the amount of disease present can be determined.
Skeletal Survey: X-rays of the bones are used to detect any bone damage caused by abnormal plasma cells. A number of x-rays can be performed throughout the body to give a full picture of the body.
PET/CT scan: This scan uses radiolabeled glucose distributed through the body to find things normal scans or x-rays may not be able to determine. It can be used to tell if bones or organs have been damaged by myeloma cells or if a patient has bone pain or other issues, but they receive a negative x-ray.
MRI: This highly sensitive test is used to determine bone and bone marrow changes associated with plasma cell disorders. MRIs show detailed images of the soft tissues in the body and are helpful at looking at the bones, brain, and spinal cord that may be impacted by the presence of multiple myeloma.
Bone Marrow Aspiration and Biopsy: A bone marrow biopsy may be performed in order to make a diagnosis or prior to a change in treatment plan. This test involves removing a small piece of the bone that contains marrow, usually from the back of the pelvic bone. In a bone marrow aspiration, a small amount of liquid bone marrow is taken, which contains marrow cells. The area is anesthetized with local anesthetic and can generally be performed in less than 10 minutes. The information from the bone marrow biopsy can determine:
- The type of plasma cell disorder and the degree of severity
- The number and percentage of normal and cancerous plasma cells in the bone marrow
- Changes in the DNA of the plasma cells which can alter prognosis. At Weill Cornell Medicine, we have the latest sequencing technology that can analyze these DNA results and use precision medicine to determine the genetic drivers of a patient’s cancer in order to develop the best treatment plan possible.
- Potential targets of new drug therapy in clinical trials
Minimal residual disease (MRD) Testing
Minimal residual disease (MRD) is a way to assess whether a patient has evidence of residual cancer cells in the body after receiving treatment. After multiple myeloma treatment,there is a possibility that a patient may be in remission, but still have myeloma cells present in the bone marrow after treatment. Residual myeloma cells can remain in very small amounts, for example at a threshold of less than one in a million.
MRD testing is a sophisticated testing method offered by the Weill Cornell Myeloma Center to find any potential residual cancerous cells. This testing method is extremely precise and is able to find cells that may not be detected through other traditional testing or imaging methods. Despite being found in such low numbers, the residual cells could still lead to disease progression or relapse. MRD testing allows our team to determine whether multiple myeloma is still present after treatment, to monitor the success of different treatments, to monitor recurrence of myeloma cells, or to determine the best treatment option for a patient.