All haematology results need to be interpreted in the context of a thorough history and physical examination, as well as previous results. Follow-up counts are often helpful to assess marginal results as many significant clinical conditions will show progressive abnormalities.
In asymptomatic people, the pre-test probability for tests is low, leading to a high rate of false positives. In addition, undertaking investigations in people who do not have a clear clinical need will use resources time and money that could be better applied to those with unmet health care needs. There are a number of features which may be revealed by history and clinical examination.
These can provide clues for diagnosis and allow the results of the complete blood count to be interpreted in context. Although the total white count may provide a useful summary, the absolute count of each of the cell types is more useful than the total.
The total white count may be misleading; e. As a result the total white count should not be considered in isolation. The normal concentration range of neutrophils is 2. The average half-life of a non-activated neutrophil in the circulation is about hours. Upon migration, outside the circulation, neutrophils will survive for days. Neutropenia is potentially associated with life threatening infection.
It is most significant when the total neutrophil count is less than 0. When the neutropenia is due to increased peripheral destruction or margination e.
These patients rarely have problems with significant bacterial infection despite quite low neutrophil counts. In routine clinical practice the most frequent cause of a low neutrophil count is overt or occult viral infection, including viral hepatitis.
Acute changes are often noted within one to two days of infection and may persist for several weeks. The neutrophil count seldom decreases enough to pose a risk of infection. A low neutrophil count is often discovered in some people as an incidental finding in the CBC result. The patient is generally asymptomatic and the clinical examination is unremarkable.
The count is usually stable on follow-up. This is likely to be idiopathic although in some cases a neutropenia may be associated with splenomegaly or an autoimmune disease such as lupus. The presentation of a haematological malignancy with only an isolated neutropenia is a rare finding. Although relatively rare, drug therapy may cause an acquired neutropenia in some people. The drugs most likely to be associated with moderate neutropenia are chemotherapy and immunosuppressive drugs, antithyroid medications, antibiotics, antirheumatics, antipsychotics and anticonvulsants.
For a more comprehensive list see Neutropenia, drug induced. Many drugs may cause a chronic mild neutropenia e. The history and clinical features are important for providing the clues for diagnosis and allowing the results to be interpreted in context.
The risk of significant bacterial infection rises as the neutrophil count drops below 1. Patients who are febrile but otherwise well should at least be discussed with a Haematologist. If the patient is well and afebrile, they need to be advised to seek medical attention promptly if their condition deteriorates or they become febrile. Well patients should have follow up blood counts within 48 hours, and if the neutropenia persists at this level or progresses they should be discussed with a Haematologist.
If an isolated abnormality follow up blood counts are indicated, with frequency dependent on the severity of the neutropenia but usually within weeks. If the neutropenia persists for more than 6 weeks further investigation is indicated.
If it is progressive or other abnormalities develop a haematology referral, or discussion with a Haematologist, is indicated. There are specific protocols for management of clozapine induced neutropenia. Otherwise, if a drug cause is suspected and the neutropenia is moderate or severe, Haematology referral, or discussion with a Haematologist is indicated.
Neutrophils are the primary white blood cells that respond to a bacterial infection. The most common cause of marked neutrophilia is a bacterial infection. Neutrophils react within an hour of tissue injury and are the hallmark of acute inflammation. Neutrophils generally exhibit characteristic changes in response to infection. The neutrophils tend to be more immature, as they are being released earlier. This is called a left shift Figure 2.
Neutrophils will frequently be increased in any acute inflammation, therefore will often be raised after a heart attack, or other infarct and necrosis. Any stressor, from heavy exercise to cigarette smoking, can elevate the neutrophil count. A number of drugs have been demonstrated to increase the neutrophil count, including steroids, lithium, clozapine and adrenalin. Even nervousness may very slightly raise the neutrophil count because of the effect of steroid release. Pregnancy is associated with a slight increase in total neutrophil count demonstrating a left shift.
Most laboratories provide pregnancy specific reference ranges. Persistent elevation of neutrophils may be a sign of chronic myeloid leukaemia CML. Chronic mild neutrophilia without left shift is very unlikely to be due to CML. CML occurs in all age groups but most commonly in the middle aged and elderly.
The annual incidence is estimated at 1 - 2 cases per , The normal concentration of lymphocytes is between 1.
There are two broad morphologic categories of lymphocytes which can be distinguished under the light microscope, large granular lymphocytes and small lymphocytes. Steroid administration may reduce lymphocyte counts. More rarely lymphocytopenia may be caused by some types of chemotherapy or malignancies.
People exposed to large doses of radiation, such as those involved with situations like Chernobyl, can have severe lymphocytopenia. Increases in the absolute lymphocyte count are usually due to acute infections, such as Epstein-Barr virus infection and viral hepatitis. Complete blood count assesses the three main categories of cells in the blood: Red blood cells which carry oxygen, White blood cells which defend against infections, and Platelets which help with blood clotting.
White blood cells in the blood consist of five main types of cells Neutrophils, Basophils, Eosinophils, Lymphocytes, and Monocytes. To be able to assess specific conditions, the analyzer gives a specific number to each type of the white blood cells. Neutrophils are the most numerous as they constitute about 50 to 70 percent of the total number of white blood cells. However, to accurately assess how many neutrophils the blood contains, an Absolute Neutrophil Count is needed.
It is not measured directly, but calculated by multiplying the white blood cell count by the Neutrophils Percentage or the Relative Neutrophil Count in the sample. Sign up and get your guide!
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White blood cells, also called leukocytes, are a key part of your immune system. Your immune system is made up of tissues, organs, and cells. As part of this complex system, white blood cells patrol your bloodstream and lymphatic system. White blood cells produce chemicals that fight antigens by going to the source of the infection or inflammation. They can move freely through the walls of veins and into the tissues of your body to immediately attack all antigens.
An absolute neutrophil count ANC can provide your doctor with important clues about your health. A CBC measures the cells that are in your blood. If your ANC is abnormal, your doctor will likely want to repeat the blood test multiple times over a period of weeks.
This way, they can monitor for changes in your neutrophil count. For the ANC test, a small amount of blood will be drawn, usually from a vein in your arm.
The blood will be evaluated in a laboratory and the results will be sent to your doctor. Certain conditions can affect the results of your blood test. Results can vary widely from lab to lab.
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