All blood cells originate from the bone marrow, from a maternal blood stem cell, which further differentiates into lymphoid stem cells predecessors of future white blood cells- lymphocytes (immune cells) and myeloid stem cells precursors of another two types of blood cells, namely red blood cells-erythrocytes and white blood cells- granulocytes( eosinophil, basophil, and neutrophil). Both types of white blood cells take part in the immune response to various infections, foreign bodies, and malignant neoplasms. Due to the miscellaneous external and internal influential factors the ordered scheme of hemgenesis (production of all blood cells in the bone marrow) might be disturbed and the consequences of this disturbance manifest in different forms of blood diseases. 

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White Blood Cells

Image: “White Blood Cells” by Blausen gallery 2014. License: CC BY 3.0

If there is a low blood cell count, in particular, white blood cells, these conditions are called neutropenia and lymphopenia; vice versa high white blood cells count is neutrophilic leukocytosis and lymphocytosis respectively. Normal white blood cells count normally ranges between 4,000 and 11,000 cells per microliter; fewer than 4,000 cells per is leukopenia; more than 11,000 cells per microliter is leukocytosis.

Definition and Background

Types of white blood cells

Monocytes: These white blood cells possess the longest lifespan amongst other white blood cells; they destroy bacteria.

Lymphocytes: They are responsible for the production of antibodies that defend the body against various infectious factors(viruses).

Neutrophils: They counteract and digest bacteria and fungi. They account for the biggest number of white blood cells and stipulate the first line of protection against infections.

Basophils: They are small cells and a hallmark of allergic reaction in the body. They secrete/produce specific chemicals- histamine, which witnesses of allergy; they control the body’s immune response.

Eosinophils: They are responsible for the specific protection of the body from parasites, destroy cancer cells, and participate in allergic responses.

Normal blood count of leukocytes

  • Neutrophils – 2.0–7.0×10 9/l (40–80%)
  • Lymphocytes – 1.0–3.0×10 9/l (20–40%)
  • Monocytes – 0.2–1.0×10 9/l (2–10%)
  • Eosinophils – 0.02–0.5×10 9/l (1–6%)
  • Basophils – 0.02–0.1×10 9/l (< 1–2%)


The etiological reasons for high white blood count:

  • Acute lymphocytic leukemia and Acute myelogenous leukemia (AML)
  • Severe allergic reactions
  • Chronic lymphocytic leukemia and Chronic myelogenous leukemia
  • Corticosteroids and epinephrine therapy
  • Various infections
  • Myelofibrosis
  • Rheumatoid arthritis
  • Smoking and alcohol abuse
  • Polycythemia Vera
  • Emotional or physical stress
  • Tuberculosis

The etiology of low white blood cells count:

  • Viral infections disrupting bone marrow stem cell production
  • Congenital diseases impairing bone marrow function (Kostmann’s syndrome associated with low production of neutrophils; Myelokathexis failure of neutrophils to enter the bloodstream )
  • Cancer
  • Autoimmune diseases (lupus and rheumatoid arthritis and other autoimmune disorders)Severe infections declining hemogenetic function of the bone marrow
  • Antibacterial therapy destroying white blood cellsSarcoidosis
  • Tuberculosis
  • Aplastic anemia
  • Chemotherapy (immunosuppressive effect)
  • Radiation therapy
  • Enlarged spleen- exceeded destruction and further utilisation of blood cells by the spleen
  • Leukemia
  • Malnutrition and vitamin deficiencies
  • Myelodysplastic syndrome



It is always associated with severe infections, as the body loses its ability for protection from pathogenic agents.

This condition usually manifests with these symptoms:

  • Fever
  • Sore mouth(oral mucosa is always affected manifesting in gingival pain and swelling)
  • Difficulties while swallowing
  • Skin abscesses (impetigo)
  • Otorynilanryngeal infections (recurrent sinusitis and otitis
  • Respiratory infection ( cough, breathlessness)


It is associated with recurrent infections or lifelong infections (congenital, family history), exposure to aggressive chemicals, radioactivity and ceratin drugs. This condition manifests with these symptoms:

  • Sever malaise
  • High grade fever, possibly with chills and confusion
  • Painful stomatitis( bleeding and friable mucosa)
  • Pharyngitis, with difficulty in swallowing

Neutrophilic leukocytosis

Neutrophilia stands for a higher than normal number of neutrophils in the blood. Neutrophilia may be a consequence of a shift of cells from the marginal to the circulating pool (shift neutrophilia) if there is no any increases in the total blood granulocyte pool (TBGP) or a true increase in TBGP size (true neutrophilia).

This white blood cells disorder is associated with bacteremia, Hodgkin`s lymphoma, pneumococcal pneumonia, urinary tract infection, inflammatory bowel disease, rheumatoid arthritis, and vasculitis (Kawasaki syndrome).

Shift neutrophilia

It is a transient condition and lasts for 20-30 minutes due to various reasons, such as excessive physical loads, seizures, paroxysmal tachycardia attacks, injections of epinephrine. The quantitative properties do not change, as the inflow of the cells remains the same.

True neutrophilia

This condition occurs due to severe infections thus TBGP may elevate by 5-6 times. When the utilization of neutrophils increases, the bone marrow cell production intensifies, shooting numerous immature forms of neutrophils stipulating left shift in the CBC.


This white blood cells disorder is associated with low number of lymphocytes, usually due to severe viral infections oppressing the bone marrow function or when infection kills more arenovirus in alcoholic hepatitis), myelodysplastic syndrome, dengue disease, Hodgkin’s lymphomas, lupus, AIDS, cancer, leukemia, consequences of chemotherapy.


Lymphocytes are responsible for the immune response in the body to different foreign agents, when the bone marrow is provoked for the excessive production of blood cells (infections Bartonella, Brucellosis, Pertussis, Paratyphoid, Typhoid, Syphilis, Tuberculosis, Adenovirus, Coxsackie, Cytomegalovirus, Epstein Barr Virus, Hepatitis, Herpes, Human T-lymphotrophic virus type 1, Measles, Mumps, Poliovirus, Varicella), Leukemia, Sickle cell anemia.

Review Questions

The right answers can be found below the references.

1. A 12 years old patient complains on painful swallowing, bleeding gums, high grade fever, and severe fatigue after insignificant physical load. The patient is confused, drowsy, and asks for water every 10 minutes. Physical examination reveals pallor, diffuse petechial rash on the skin surfaces. There are recurrent infectious diseases in the history: impetigo, pertussis, hepatitis A and frequent flu. There are purulent plaques on the pharyngeal glands. What is the most probable white blood cells disorder may present here?

  1. Neutropenia (agranulocytosis).
  2. Neutrophilia.
  3. Lumphocytosis
  4. Lymphopenia
  5. None of above

2. Increase in the total blood granulocyte pool (TBGP) stands for true neutrophilia. What white blood cells stipulate this condition and what is the most probable triggering factor for this condition?

  1. Immature granulocytes/ infection
  2. Mature granulocytes/ infection
  3. Immature lymphocytes/ cancer
  4. Mature lymphocytes/ cancer
  5. None of above

3. The laboratory saliva study presents Epstein- Barr virus in 29 years old male immune compromised patient; he is a drug addict, with proved pneumococcal pneumonia. What white blood cells disorder are the most probable in this clinical case?

  1. Lymphopenia
  2. Lymphocytosis
  3. Neutropenia
  4. Neutrophilia
  5. None of above
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