An Overview Of A Low White Blood Cell Count As A Side Effect Of Chemotherapy

Chemotherapy can be life saving in treating cancers. However, it also has many side effects, one of which is an adverse impact of production of low white cells in the body, which are crucial for body resistance to infections. Understanding and monitoring white cell count can enable addressing this challenge.
An Overview of a Low White Blood Cell Count as a Side Effect of Chemotherapy
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Development of Chemotherapy has allowed mankind to win many battles against cancer. However, chemotherapy has many adverse effects too, the most severe of which is fall in white blood cell count that makes the body vulnerable to infections. A greater awareness of this condition may help us prepare better to deal with it, and fight more effectively against cancer.


CHEMOTHERAPY refers to treatment of cancer by use of medication, which selectively destroy cancer cells. It protects the body from cancer, but it also leads to side effects including a fall in white blood cell count.

How Chemotherapy Leads to Low White Blood
Cell Count

The chemotherapeutic drugs used against cancers destroy the fast growing abnormal cancer cells, but while doing so, they also damage normal cells. The chemotherapeutic medicines interfere with the process of cell division, by which cells grow and multiply. Because of this effect, their damaging impact is maximum on the rapidly multiplying cells due to the fact that multiplying cells are most vulnerable and  get affected to a much greater extent compared to cells in a stable state.

Since the cancer cells grow very fast, these medicines interfere in their growth and destroy them. There are several type of normal cells in the body that also grow and multiply faster than other cells, and hence are destroyed by the cancer chemotherapy. These include red and white cells of blood, platelets, hair cells, skin, mucosal cells lining the inside of mouth, stomach and intestines. Damage to these cells causes the adverse side effects associated with chemotherapy.  Destruction of growing cells in bone marrow and lymphatic tissue leads to a fall in the white blood cell count in blood.

Impact of Low White Blood Cell Count

LEUCOCYTES or white blood cells are the main defence of the body against infection by micro-organisms. The normally white blood cell count range is from 4000 to 11000 cells per micro litre of blood. When this count falls below 4000, it is considered as 'low white blood cell count' or 'LEUCOCYTOPENIA.' There are five different types of white blood cells - NEUTROPHILS, LYMPHOCYTES, MONOCYTES, EOSINOPHILS and BASOPHILS. Neutrophils make up around 40 to 45 % of all white blood cells, and hence, a low white

blood count usually refers to a fall in the neutrophils count or NEUTROPENIA.

A fall in the white blood cell count adversely affects the immunity of the body, i.e.. the ability to ward off invading bacteria and other micro-organisms. Lower the white blood cell count in bold, greater will be the vulnerability to infections. ABSOLUTE NEUTROPHIL COUNT (ANC) indicates this risk. Till the ANC is above 1500/ul, the increase in risk is not significant. Once it falls below 1500/ul, the frequency of infections starts rising. With an ANC under 1000 to 500 per micro litre, the risk becomes very high, and at an ANC below 100/ul, the risk of infection becomes extremely high.

Consequences of Untreated White Blood Cell Count

If the low white blood cell count continues to remain untreated, there can be significant consequences. The most important consequence is increased vulnerability of infections. There can be different types of bacterial infections right from sore throat to skin infections. A person with low white blood cell count can also get infections which a person with adequate immunity is unlikely to get. There could also be an increased frequency of fungal infections like CANDIDIASIS and TINEA.

Ironically, the fall in white blood cell count as a result of chemotherapy can itself become a cause of cancers. This is because the white blood cells help in removing mutated cells which eventually lead to cancers. When the white blood cell count falls, this protection is lost and probability of cancers later in life increases.


When there is a fall in the white cell count in a cancer patient undergoing chemotherapy, it is adequate indication for taking precautions against contracting infections. Proper hygiene, avoiding exposure to polluted air and water, avoiding crowded places and contact with sick or infected people is preferable. In severe cases, if the ANC falls below 500/ul, prophylactic antibiotic therapy with CO-TRIMOXAZOLE or other antibiotics can also be considered.

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