الخلايا القاعدية في تحليل الدم: شرح مبسط

This test measures how many basophil granulocytes circulate in your blood. Basophils are one of the five types of white blood cells in the differential.

The result appears in two ways. The first is a percentage of the total white blood cell count. The second is an absolute number in billions of cells per litre. The absolute figure is the more useful one, because a percentage moves with the other cell types.

Basophils are the rarest of all white blood cells. Normally they make up 0 to 2 percent of the total. Converted, that is 0 to 0.2 x10⁹/l in adults.

The basophil is related to the mast cell in tissue. Both contain histamine and heparin. Those substances are released during an allergic reaction.

The basophil granulocyte count is measured automatically within the complete blood count. That panel also counts the red blood cells and the platelets. You therefore rarely request basophils on their own.

One point matters more here than for the other cell types. Automated analysers count basophils least accurately of all. Near the decision limit the measurement uncertainty rises above twenty percent. A striking result is therefore confirmed first with a manual blood smear.

Basophils release histamine and heparin. That involves them in allergic reactions and in inflammatory processes in tissue.

Even so, their number in the bloodstream says less than you might expect. The NVKC notes that basophils act mainly in allergically affected tissue. The count in blood therefore says little about an allergy. A normal value does not rule an allergic reaction out. A raised value does not prove one either.

A value above 0.2 x10⁹/l is called basophilia and is uncommon. The most common causes are reactive in nature. They include prolonged allergic reactions, chronic inflammation and an underactive thyroid. Some autoimmune diseases can also come with a mild rise.

In parasitic infections it is mainly the eosinophil granulocyte count that rises. Basophils may rise alongside, but they are not the best measure of it.

The clinically important point is not about a single measurement. A persistent, unexplained rise is a reason for a doctor to look further. That applies especially when the total white blood cell count is also raised. In that combination a doctor judges whether further investigation is needed.

One mildly raised result is emphatically not a persistent rise. Given the measurement uncertainty of this assay, the same person can produce a different value on repeat. The trend across several measurements therefore weighs more than one number.

A low count has no demonstrable meaning. The lower limit of the normal range is zero, so below normal barely exists here.

Basophils are measured within the complete blood count with differential. You generally do not request them separately, because the value gives little direction on its own.

The test belongs to a general picture of your immune defence and blood production. Within it, basophils sit beside the neutrophils, lymphocytes, monocytes and eosinophils.

A repeat measurement is worthwhile when a rise stands out. The reason is the measurement uncertainty of this assay. A second reading shows whether the rise persists or resolves by itself.

A doctor looks further when a rise persists without a clear explanation. The same applies when other values in the same blood count are abnormal. The combination weighs more than a single figure.

There is no reason to test because of a low or absent count. Zero is a normal result and calls for no follow-up.

No fixed preparation is required. Fasting is not needed for this test. Do mention which medicines you take, because your doctor weighs that when assessing the whole blood count.