Leukocytosis with Normal Bone Marrow
In most instances, increased white blood cell counts are the result of normal bone marrow reacting to inflammation or infection. Most of these cells are polymorphonuclear leukocytes (PML). Circulating PML and less mature forms (e.g., band cells and metamyelocytes) move to a site of injury or infection. This is followed by the release of stored leukocytes, commonly referred to as a "left shift." Inflammation-associated leukocytosis occurs in tissue necrosis, infarction, burns and arthritis.



Leukocytosis may also occur as a result of physical and emotional stress. This is a transient process that is not related to marrow production or the release of band cells or other immature cells. Causes of stress leukocytosis include overexertion, seizures, anxiety, anesthesia and epinephrine administration. Stress leukocytosis reverses within hours of elimination of the inciting factor.

Other causes of leukocytosis include medications, splenectomy, hemolytic anemia and malignancy. Medications commonly associated with leukocytosis include corticosteroids, lithium and beta agonists. Splenectomy causes a transient leukocytosis that lasts for weeks to months. In hemolytic anemia, nonspecific increases in leukocyte production and release occur in association with increased red blood cell production; marrow growth factors are likely contributors. Malignancy is another recognized cause of leukocytosis (and, occasionally, thrombocytosis); the tumor nonspecifically stimulates the marrow to produce leukocytosis.
An excessive white blood cell response (i.e., more than 50,000 white blood cells per cm3 [50 X 109 per L]) associated with a cause outside the bone marrow is termed a "leukemoid reaction." Even this exaggerated white blood cell count is usually caused by relatively benign processes (i.e., infection or inflammation). An underlying malignancy is the most serious but least common cause of a leukemoid reaction.

As mentioned previously, an increase in neutrophils is the most common cause of an elevated white blood cell count, but other subpopulations of cells (eosinophils, basophils, lymphocytes and monocytes) can also give rise to increased leukocyte numbers





Comments

Shru90, United Arab Emirates

I did my blood test and my t.wbc count is 77200..pls leme noe wt cud b de possible problem

Lakshmivasantha, India

My daughter age is 4 years 4 months. Her WBC count is 18600 and C reactive protein level is 43.5 mg/L. I want to know what does above results are indicating

Al_tm, Indonesia

tissue necrosis : CIRROSIS 0f hepatic.. well done.. thanx :)

khammar12, Morocco

well written and very informative.

Curious, India

leukocytosis can occur due to overt exitation, Severe stress,Burns, Dehydration,Hypoxia,Gangrene and excess of steroids.