If I recall correctly. Which I often don't.
Mine are paid for, but I don't know what hoops my ME specialist had to jump through to make that happen. It probably helps that she's a highly respected academic immunologist, so the insurance company weenie know-nothing so-called medical specialist didn't dare claim he or she know more about the matter than my doc. And I have really good insurance.I haven't had NK cells measured. I saw one site for measuring them, it looks expensive. Maybe insurance pays for it???
Not to the extent ours is reduced, I believe. The magnitude of the drop in function does matter.It is apparently well established in the literature that psychological stress can cause reduced NK cell function.
Again, details matter. There are a lot of cytokines, two directions they can be disturbed, and a large range in which the magnitude can vary. Vague minor similarities in lab results occur across all kinds of diseases. It's more the complex patterns that matter. Vague similarities like some cytokines change in some way in different diseases don't mean much. Probably hundreds of diseases have some cytokine disturbance. That doesn't mean the diseases are related. Now if the patterns (which cytokines changed in which direction and how much) are very similar, that's another matter.
"NK cell dysfunction" may or may not mean the far below normal range NK cell function seen in ME. Details matter.
The study I found about NK cells and psychological stress studied NK cell function immediately after (<2 hrs) acute stress (novice skydivers on their first jumps). They found significant decreases from their normal baseline levels. Significant decrease doesn't mean a plummet far below normal range. Significant means it's noticeable enough that it's not likely to be random. That's not anywhere near the same thing as persistently very low NK cell function, far below normal ranges, for years on end. We are not experiencing acute stress anywhere near that level and yet our NK cell dysfunction tends to be severe. The situations are hardly comparable.
I did not see any papers correlating severe, persistent very low NK cell function with PTSD. That doesn't mean they don't exist of course. If you can point to reliable research (done by immunologists, not psychologists) that the cytokine and NK cell function disturbances in psychological stress, PTSD, and ME are very similar in detail, I'd love to see them. It would be interesting to see in what ways the disturbances are alike and in which ways different.
Just so's ya know, I'm not one of the ME patients with persistently very low NK cell function, so I don't have a dog in this fight. I just think we need to look at these issues as the complex issues they are and not grossly oversimplify them.
When highly knowledgeable immunologists who also study ME think these immune disturbances mean something, I'm inclined to listen.