What are the blood count basics in CLL?

Understanding changes in basic blood counts is important in monitoring and managing CLL. There are three major types of blood cells: red blood cells (erythrocytes), white blood cells (leukocytes), and platelets (thrombocytes).

Red blood cells (RBC's) are the major component of blood. They carry oxygen and carbon dioxide throughout the body. The percentage of red blood cells in the blood is called the hematocrit. The part of the red blood cells that carries oxygen in a protein is called hemoglobin.

White blood cells (WBC's) are the main component of the immune system, the body's defence mechanism that fights and destroys such foreign substances as bacteria and viruses. There are several types of white blood cells, each with its own function in protecting the body from germs. Three major types of white blood cells are granulocytes (neutrophils, eosinophils, and basophils), monocytes, and lymphocytes.

Platelets prevent excessive bleeding by helping blood clot at the site of an injury. An abnormally low platelet count (thrombocytopenia) may result in small vessel bleeding (petechiae) or in excessive bleeding from wounds in mucous membranes, skin, or other tissues (hematomas).

Normal blood counts are difficult to state as they vary with the age and sex of the patient as well as where they live. Higher values are usually seen in people who live at higher elevations. The reference ranges for each test will be printed on the laboratory report form and will be specific to your locale. (see also: What do laboratory reference ranges mean?)

On the whole, adult values are typically:

  • Red blood cells:
    		•  In males, 4.6 to 6.2 million per microliter of blood or 4.6 - 6.2x1012/L
    In females, 4.2 to 5.4 million per microliter of blood or 4.2 - 5.4x1012/L
  • White blood cells:
    		•  4,000 to 11,000 per microliter of blood or 4.0 - 11.0x109/L
  • neutrophils:
    		• 50% to 60% of total white blood cells
  • monocytes:
    		• 3% to 10% of total white blood cells
  • lymphocytes:
    		• 25% to 35% of total white blood cells
  • eosinophils:
    		• 0% to 3% of total white blood cells
  • basophils:
    		• 0% to 2% of total white blood cells
  • Platelets:
    		•  150,000 to 350,000 per microliter of blood or 150 - 350x109/L
  • Hemoglobin:
    		•  In males, 14 to 18 grams per 100 milliliters of blood or 14 - 18g/dL. (In some countries, these values are given in liters, so they read 140 - 180 g/L.)
    In females, 12 to 15 grams per 100 milliliters of blood or 12 - 15g/dL.
  • Hematocrit:
    		•  The percentage of red blood cells per microliter of blood:
    In males 40% to 54%
    In females 35% to 47%

    When speaking about these values, many practitioners use a shortened language by omitting adjectives such as grams. For example, suppose the white cell count is 10.5x109L. Since all white cell counts end in 109L, the number spoken is just the 10.5. A hemoglobin value would be 14 instead of 14 grams per deciliter.

    One calculation that is very important is the absolute cell count. This is achieved by multiplying the total white cell count by the percent of a specific cell reported. Based on these figures, the normal lymphocyte count is in the range of 1,000 to 3,850 per microliter of blood or 1.0 - 3.8x109L. Often the first symptom of CLL is an above normal lymphocyte count, which is discovered in a routine blood test.