Not All Immune Cells Are Out Circulating

"They say my white cell count is up. Where am I unwell?"

Some people come in holding a health check result and ask this. The body seems fine and only the number has risen, so it is unsettling.

It does rise, of course, when there is infection or inflammation. But that is not all it is. There are cases where it rises not because white cells increased, but because the place they were standing changed.

White cells are not all flowing

Picture white cells in the blood and you tend to draw them riding the bloodstream around the body. That is about half right.

A good share of them wait close against the vessel wall. Not in the middle of the flow but along the edge, rolling slowly against the wall or standing still for a while. This group is called the marginated pool — meaning it sits at the edge, the margin, of the vessel.

A blood draw takes flowing blood. So the cells waiting against the wall are not caught by that needle. The number on the report is, from the start, a count of the flowing side only.

Why stay against the wall at all

This is the interesting part. Once I knew about this arrangement, I came to look at white cell counts differently.

The place where things happen is not inside the vessel but the tissue. When something is injured or a microbe gets in, white cells have to leave the vessel and enter that tissue. To do that, they first have to attach to the wall.

A cell circulating fast through the middle of the flow takes time to reach the wall. Being attached near the wall in advance means it can get out that much sooner. It is a little like parking a fire engine at the roadside rather than putting it away in the garage.

That the body keeps this group set aside also means getting out quickly matters that much.

Tension sends them dropping off all at once

The waiting cells come off the wall and return to the flow when they are needed. But the signal that makes that happen does not come only from infection.

It happens with hard exercise, with a sudden fright, when tension rises abruptly. The signals released then, adrenaline among them, loosen the force holding the cells, and as the flow quickens the pushing force grows too. It has also been shown that the cells themselves soften somewhat, which makes them come away from the wall more readily.

Then the number on the report rises. Nothing was newly made — cells that were there all along moved over to the side that gets counted. Changes like this usually happen within tens of minutes, and once they pass, things return.

Which is why one number is not enough

Seen this way, a white cell count is closer to a value telling you how many are standing on the flowing side right now than how many white cells are in the body.

So when I look at this number I look at when it was measured alongside it. Whether the person ran in just before the test, whether the test itself made them very tense, whether they overdid it the day before. The same body gives a different number depending on those circumstances. (A Test Looks at the Body of That Moment)

A number that has risen alongside a fever or somewhere that hurts has to be read differently, of course. What I mean is that I do not judge by the number alone, not that the number is meaningless.

How Korean medicine set inflammation down

Korean medicine set down the site of inflammation as four things bound together: red, swollen, hot, and painful. It is a description that put down what could be seen, just as it was.

But these four are not symptoms that arose separately. They are what appears all at once when more blood is sent to that spot. The vessels widen, so it reddens and grows hot; the wall opens and fluid leaks, so it swells; and in the course of that, pain signals switch on.

So seeing these four as one bundle means reading that the sending of blood and immunity to that spot is under way. I feel there is much to learn in this passage. They read that work from the sending side.

And to send, the cells first have to attach to the wall. The group waiting close against the wall is closer to a state in which that sending has been prepared in advance.

What I do when I look at a test result

When I look at a test result I look at the circumstances of that day and the trend rather than the number.

The grain of several measurements tells me more than one raised number. And I ask alongside it whether the person falls ill often when tired, whether recovery is not what it used to be. The force that protects does not show itself in numbers alone. (Being Tired Is When to Look After Yourself)

When to be seen first

If a white cell count is repeatedly confirmed as greatly raised or lowered — especially if a fever continues, or weight drops for no reason, or bruises increase alongside it — examination comes first. Repeated results matter more than a single number.

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So I do not read a white cell count by that number alone.

When Korean medicine looked at the site of inflammation, it read what was gathering toward it. The description that bound red, swollen, hot and painful into one bundle is like that. It did not count how many there were; it looked at where things were heading.

Now we can see even how that heading is prepared. There is a group waiting close against the wall; when a signal comes they drop off; and so the number caught by a blood draw changes.

Where the cells are standing tells you more about the body that day than how many there are. Reading the numbers on a test result that way is what I do.

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Sources

• A review setting out how a good share of white cells wait attached to the vessel wall and return to the flow in response to signals, and how that movement changes test values — Journal of Leukocyte Biology, 2009
• A study showing that the softening of cells drives the process of coming away from the wall, and that clinical blood counts rise as a result — Proceedings of the National Academy of Sciences, 2016

Written by Dr. Heo Ji-young (Ph.D. in Korean Medicine Pathology, Kyung Hee University · former Research Professor of Herbology, Kyung Hee University)