cyclic neutropenia
Meaning of cyclic neutropenia: White cell counts that rise and fall on a roughly three week schedule, so illness arrives on a predictable timetable.
Definition of cyclic neutropenia
Cyclic neutropenia is an inherited disorder in which the number of neutrophils, the white blood cells that fight bacteria, swings between normal and very low on a repeating schedule of about three weeks. During each low point, which lasts a few days, mouth ulcers, fever, inflamed gums and infections appear, then settle again as the count recovers.
What makes the count cycle?
Neutrophils are made in the bone marrow and survive only about a day once they reach the blood, so the supply has to be replaced constantly. In cyclic neutropenia a fault in the gene for neutrophil elastase, an enzyme packed into the cell as it is built, produces a misshapen protein that stresses and kills developing neutrophils in the marrow. The marrow answers by pushing production up, overshoots, then falls short again, and the whole line settles into a swing that repeats roughly every three weeks. Other blood cells drift up and down in step with it, but only the neutrophil dip is deep enough to cause trouble. The fault is usually inherited from a parent and is present from early childhood.
What happens at the low point?
Symptoms follow the trough rather than arriving at random. Mouth ulcers, sore swollen gums, tender neck glands and a fever lasting a few days are the familiar pattern, and the same sequence returns on a schedule families often learn to anticipate. Because the gums are attacked over and over across years, gum disease and early tooth loss are common. The graver risk is different: with almost no neutrophils to contain them, bacteria that normally live quietly in the bowel can invade its wall and reach the bloodstream. Identifying the pattern means counting neutrophils several times a week over a couple of months, since a single sample drawn at the wrong moment looks entirely normal.
How does it differ from other causes of low neutrophils?
| Form | Pattern of the count | Usual driver |
|---|---|---|
| Cyclic | Regular swings with a roughly three week period | Inherited elastase gene fault |
| Severe congenital | Very low and staying there from birth | Marrow arrest early in neutrophil production |
| Treatment related | Dips after each dose, then recovers | Marrow suppressed by chemotherapy |
| Autoimmune | Steadily low, often in young children | Antibodies directed at neutrophils |
The distinction matters because the outlook is not the same. Unrelenting neutropenia from birth, as in Kostmann neutropenia, carries a real risk of the marrow turning leukemic later, while the cyclic form carries far less. A fever arriving during a trough is handled with the urgency given to febrile neutropenia anywhere else, because pus, redness and swelling are made by neutrophils and are muted or missing when there are none.
Also known as
Used in a sentence
Serial counts over two months showed the regular oscillation of cyclic neutropenia.
Good to know
Because the count is normal for most of each cycle, a blood sample taken between troughs looks unremarkable, and the diagnosis rests on repeated counts over weeks rather than on any single result.
Word origin
Where “cyclic neutropenia” comes from
Neutropenia joins neutro-, from the neutrophil, with the Greek penia, meaning poverty or lack. Cyclic comes from the Greek kyklos, a circle or wheel.