Ask The Nurse // 31st January 2020
Many of the symptoms and complications caused by myeloma are due to changes to the blood, for example anaemia (low red blood cells). As a result, a blood test known as a full blood count is an important part of regular check-ups. However, it can be difficult to understand exactly what the results mean. We often get questions from patients and carers wanting to know more about blood tests and how myeloma and its treatments affect the blood. In this month’s blog, we wanted to answer some of the questions you ask us about how myeloma affects blood cells and how changes in blood cell levels are measure.
What is blood?
There are three types of cells in your blood; red blood cells, white blood cells and platelets.
Red blood cells (erythrocytes) are the cells in the blood that carry oxygen around the body.
White blood cells are a group of cells in our blood that form part of the immune system.
Platelets (thrombocytes) are the cells in the blood that stop bleeding when a blood vessel is cut or damaged.
Why does myeloma affect my blood when the cancerous cells are found in my bones?
The bone marrow, the spongy part inside your bones, is the main site of blood cell production (haematopoiesis) with red blood cells, platelets and most white blood cells being made there. As myeloma develops in the bone marrow, the abnormal plasma cells (myeloma cells) overcrowd the bone marrow reducing the production of healthy blood cells. This can cause the level of platelets, red blood cells and white blood cells in the blood to fall.
Complications caused by low blood counts due to the myeloma itself normally improve with anti-myeloma treatment. As treatment begins to bring your myeloma under control, your bone marrow is often able to recover and will start producing normal amounts of platelets and other healthy blood cells.
Why does my healthcare team routinely test my blood? What are they looking for?
As part of your diagnosis or ongoing check-ups, your healthcare team will take your blood and run a number of tests including a full blood count. In this test, they are assessing the condition of your blood and checking to make sure all the cells in your blood are at the right level. This helps your healthcare team know if any of your blood cell levels are low and whether you need any supportive treatments.
Some of the measurements you may see in your results or that your team might talk to you about include:
- Haemoglobin level: Haemoglobin is the protein that red blood cells use to carry oxygen. It is a measure of how many red blood cells are in your blood. The normal range for haemoglobin is 115–160 g/L for women and 135–180 g/L for men. A low haemoglobin level is a sign of anaemia. Anaemia can cause symptoms like breathlessness, fatigue or dizziness
- Platelet count: A measure of how many platelets are in your blood. The normal range is 150–400 x109/L. A low platelet count is known as thrombocytopenia. Signs of thrombocytopenia can include bruising, nosebleeds and/or prolonged bleeding from cuts
- White blood cell count: A measure of all the white blood cells in your blood. The normal range is 4.0–11.0 x109/L. A low white blood cell count suggests that your immune system is compromised and you are at greater risk of infection
- Absolute neutrophils count: Neutrophils are a type of white blood cell. They are the most common type of white blood cell in the bloodstream and are among the first immune cells to defend against infection. The normal range is 5–7.5 x109/L. A low absolute neutrophil count is known as neutropenia. Neutropenia can be a side effect of high-dose therapy and stem cell transplantation. Therefore, absolute neutrophil count is a key measure of recovery
If the anti-myeloma treatment is killing my myeloma why has my blood cell count gone down?
Reduced blood cell production, resulting in low blood cell counts, is a common side effect of anti-myeloma treatments including thalidomide, bortezomib (Velcade®), lenalidomide (Revlimid®), daratumumab (Darzalex®), cyclophosphamide and melphalan.
Blood cell counts will usually improve during the non-treatment or rest days of your treatment cycle. However, in some cases, particularly if severe, it may be necessary to temporarily reduce your dose or postpone treatment until your blood cell counts begin to return to normal.
For more information about tests and investigations, you can read the Myeloma UK Infoguide “Tests and investigations in myeloma”, which is available to download from the Myeloma UK website.
If you have any questions about test results you can also get in touch with us through the Infoline (0800 980 3332 (UK) or 1800 937 773 (Ireland)) or the Ask The Nurse email service.
The Myeloma UK Information Specialist Team