Basophilia 
Basophilia is an uncommon cause of leukocytosis. Basophils are inflammatory mediators of substances such as histamine. These cells, along with similar tissue-based cells (mast cells), have receptors for IgE and participate in the degranulation of white blood cells that occurs during allergic reactions, including anaphylaxis. Causes of basophilia, some of uncertain origin, are listed in Table 3.



Lymphocytosis
Lymphocytes normally represent 20 to 40 percent of circulating white blood cells. Hence, the occurrence of lymphocytosis often translates into an increase in the overall white blood cell count. Increased numbers of lymphocytes occur with certain acute and chronic infections (Table 4). Malignancies of the lymphoid system may also cause lymphocytosis.
Relative, rather than absolute, leukocytosis occurs in a number of clinical situations, such as infancy, viral infections, connective tissue diseases, thyrotoxicosis and Addison’s disease. Splenomegaly causes relative lymphocytosis as a result of splenic sequestration of granulocytes.


Table 4 - Etiology of Lymphocytosis
Absolute lymphocytosis
Acute infections: cytomegalovirus infection, Epstein-Barr virus infection, pertussis, hepatitis, toxoplasmosis
Chronic infections: tuberculosis, brucellosis
Lymphoid malignancies: chronic lymphocytic leukemia
Relative lymphocytosis
Normal in children less than 2 years of age
Acute phase of several viral illnesses
Connective tissue diseases
Thyrotoxicosis
Addison’s disease
Splenomegaly with splenic sequestration
Table 5 - Clinical Factors Increasing Suspicion of an Underlying Bone Marrow Disorder
Leukocytosis: white blood cell count greater than 30,000 per mm3 (30 X 109 per L)*
Concurrent anemia or thrombocytopenia. Organ enlargement: liver, spleen or lymph nodes.
Life-threatening infection or immunosuppression.
Bleeding, bruising or petechiae Lethargy or significant weight loss

Leukocytosis with Primary Bone Marrow Disorders
Clinical factors that increase suspicion of an underlying bone marrow disorder are listed in Table 5. Bone marrow disorders are generally grouped into leukemias and myeloproliferative disorders.
Marrow abnormalities may occur with stem cells (acute leukemia) or more differentiated cells (chronic leukemia). Delineating acute leukemias from chronic leukemias is clinically important because the acute forms are more often associated with rapidly life-threatening complications such as bleeding, brain infarction and infection. Differences in the clinical presentations of acute and chronic leukemias are provided in Table 6.





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.