Blood count and blood group · Blood

Basophils

The rarest white blood cells, involved in allergic reactions; as a single value rarely meaningful.

At a glance

Measured in blood
In 5 test panels
No special preparation

Explanation

Basophils: what is measured?

The analysis counts the number of basophilic granulocytes (basophils) per liter of blood, as part of the white blood cell differential. Basophils are the least common type of white blood cell: normally only a very small proportion of all white blood cells. They contain substances such as histamine that are released during allergic reactions and inflammation. Because basophils mainly work in the tissues, their number in the blood says little about an allergy, according to the Dutch Society for Clinical Chemistry (NVKC); the value is mainly assessed as part of the complete blood count.

What can it detect?

Allergic and inflammatory reactions, some viral infections and an underactive thyroid (slightly raised count, not very specific)
Rarely: a bone marrow disease such as chronic myeloid leukemia or another myeloproliferative disorder (persistently and clearly raised count, usually with other abnormalities)

Result

What does the result mean?

Basophils too high

A slightly raised basophil count (basophilia) occurs with allergies such as hay fever or hives, with inflammatory diseases such as rheumatism or an inflammatory bowel disease, with some viral infections, with an underactive thyroid and with iron deficiency. Usually such a slight rise is temporary and has no consequences. Rarely: a bone marrow disease such as chronic myeloid leukemia (CML) or another myeloproliferative disorder, especially with a persistently and clearly raised count together with a strongly raised total white blood cell count, an enlarged spleen or abnormal platelets. The GP then has the blood examined under the microscope and, if needed, refers to a hematologist.

Basophils too low

A low basophil count almost never has any significance: the normal lower limit is zero, so a result of 0 is normal. The count falls with acute infections, stress, use of prednisone or other corticosteroids, an overactive thyroid and during ovulation or pregnancy. None of these situations calls for further investigation of the basophils themselves.

After an abnormal result

A slightly raised basophil count without other abnormalities is usually not followed up separately; the GP looks at the complete blood count and repeats the measurement after a few weeks if needed. With a persistently and clearly raised count together with other abnormalities in the blood count, the GP has the blood examined under the microscope and, if there are signs of a bone marrow disease, refers to an internist (specialist in internal medicine) or hematologist.

Reliability

How reliable is the test?

Basophils are so scarce that the count in an ordinary blood sample is based on a few dozen cells; the measurement is therefore less precise than that of the other white blood cells and the percentage fluctuates from day to day. As a single value, the basophil count is therefore hardly interpretable; according to the Dutch Society for Clinical Chemistry (NVKC), the number in the bloodstream does not say much even in allergy. The value only becomes meaningful in combination with the total white blood cell count, the other types, the hemoglobin and the platelets; a strongly abnormal blood count can rarely point to a blood disease, and the GP then investigates further.

What can affect the result?

Because of the low number of cells, the count is relatively imprecise; a difference between 0 and 1 percent is usually chance.
Allergies, inflammation and infections in the weeks before the blood draw slightly raise the count; corticosteroids, stress and acute infections lower it.
When blood is in transit to the laboratory for a long time, the differential is less reliable, because the cells change shape.
With abnormal results from the cell counter, a count is done under the microscope, which has its own imprecision; reference values differ between laboratories.

Who it is for

Who is the test useful for?

Useful for

Only useful as part of an extended blood count with differential; as a separate test, the basophil count has no value. This test is not suitable for investigating an allergy; targeted allergy tests exist for that.

How common is it?

A slightly raised basophil count with allergy or inflammation is common and rarely has consequences. A persistently raised count due to a bone marrow disease is rare.

Drawbacks and risks

A slightly raised basophil percentage is often flagged as abnormal in result lists, even though it almost never has any significance; this can cause unnecessary worry.
A normal basophil count says nothing about the presence or absence of an allergy.

Get tested

Basophils: test panels

Basophils is part of these test panels. You order online and have your blood drawn at a collection point or collect the sample at home.

Blood draw
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Complete Blood Count Extended; standard blood count plus detailed white blood cell analysis.
€ 27,00
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Comprehensive blood analysis with biomarkers that integrates directly with your WHOOP wearable for optimal performance and recovery.
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Fingerstick
Full blood count with differential (CBC) (finger-prick)
Full blood count including haemoglobin, platelets and a white cell differential.
€ 27,00

How reliable is the test?

Basophils