Tests to assess blood cells

Blood tests are routinely done during diagnosis and throughout the disease course. These tests assess:

• response to treatment
• side effects
• signs of possible relapse

Complete Blood Count (CBC)

The Complete Blood Count (CBC) is a basic test done during every medical check-up. It is one of the most important blood tests used for diagnosing and monitoring myeloma patients. 

A routine blood test may identify a case of

• multiple myeloma
• smoldering multiple myeloma
• monoclonal gammopathy of undetermined significance (MGUS)

The CBC is a blood test that quantifies all the cells that make up the solid parts of blood. 

The bone marrow is where myeloma grows. All your blood cells – red blood cells (RBC), white blood cells (WBC), and blood–clotting cells called platelets – are made in the bone marrow. 

Both myeloma itself and the many treatments for myeloma affect the ability of new blood cells to grow in the bone marrow.  

Your CBC will be monitored carefully throughout your treatment course to make sure that your blood cell counts are not decreasing to dangerous levels. Sometimes, patients must have a CBC every week to ensure that a particular treatment is not taking a toll on one or more of the blood cell types.  

What Does a Complete Blood Count Measure? 

Red blood cells (RBC) 

REFERENCE RANGE (10¹² = 1 trillion) 

For males 4.32–5.72 x 10¹²/L 

For females 3.90–5.03 x 10¹²/L 

Red blood cells are also called erythrocytes. These cells in the blood  contain hemoglobin, deliver oxygen to all parts of the body, and take away  carbon dioxide. Red blood cells are usually the first to decrease in number in response to active myeloma. 

Hemoglobin (hgb) 

REFERENCE RANGE 

For males 13.5–17.5 g/dL (135–175 g/L) 

For females 12.0–15.5 g/dL (120–155 g/L) 

Hemoglobin, the most important part of the red blood cell, is a protein that transports oxygen to the organs and tissues of the body. A low hemoglobin count can be a sign of anemia, one of the CRAB criteria that are characteristic of active myeloma: elevated Calcium, Renal (kidney) dysfunction, Anemia, and Bone disease. The doctor will keep a close watch on your hemoglobin throughout your myeloma disease course, as it can be an early indicator of myeloma activity in the bone marrow. 

Hematocrit (hct)

REFERENCE RANGE 

For males 38.8%–50.0% 

For females 34.9%–44.5% 

Hematocrit is the volume percentage of red blood cells in the blood. Usually, the percentage of RBC is about 45% for men and 40% for women. 

White blood cells (WBC) 

REFERENCE RANGE (10⁹ = 1 billion) 

3.5–10.5 x 10⁹/L 

White blood cells make up the body’s immune system. They fight foreign substances that enter the body, including bacteria, viruses, and toxins. Low WBC counts can result from many types of treatment for myeloma, which can further diminish your ability to fight disease. Your WBC count will be followed carefully during your treatment for myeloma. 

Neutrophils 

REFERENCE RANGE 

1.7–7.0 x 10⁹/L 

Neutrophils are a type of WBC that helps fight infections, particularly those caused by bacteria and fungi. A low neutrophil count is called neutropenia, a condition that results in susceptibility to infection. Your doctor will check your neutrophil count, sometimes expressed as ANC (Absolute Neutrophil Count, which measures both mature and immature neutrophils), to make sure that it is safe to give you a dose of a particular treatment. 

Platelets 

REFERENCE RANGE 

150–450 x 10⁹/L 

Platelets are blood cells that help the blood to clot and prevent bleeding. Low hemoglobin is a more common blood-related symptom of myeloma than is a low platelet count (thrombocytopenia). Yet, some patients do have low platelets at diagnosis as a result of their myeloma. In addition, certain treatments for myeloma can also cause low platelets. These treatments include these proteasome inhibitors:  

• Velcade® (bortezomib) 
• Kyprolis® (carfilzomib) 
• Ninlaro® (ixazomib) 

These treatments may cause severe bruising or bleeding. Your platelet count should be monitored throughout your disease course. 

Learn more about these blood cell types and subcategories, visit the Understanding Your Test Results booklet, pp. 9–13.

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