Anxiety panic and inflammation

About seven years ago, I started experiencing bouts of mystery swelling in my feet and knees. A couple of days of swelling, in the minor cases. A couple of weeks, in the more major ones. Sometimes the swelling would come after a long hike or the likes. Sometimes, though, there was no real cause that I could point to; the swelling simply came from out of the blue.

This is real pain I'm talking about. In my time I've suffered more than my share of cuts, scrapes, bumps, bruises, burns, dislocations, sprains, muscle pulls, and whatnot. I've broken my neck (5th C.V., playing rugby in college), gone under the knife, been bloodied in fights. The pain I'm talking about is right up there with all of that, typically. Indeed, one bout of mystery swelling was the most painful thing I've ever experienced. (As in, the weight of a mere bedsheet on my foot caused me to cry agonized tears.)

I attributed the mystery swelling bouts to aging and wear and tear, basically. In my lifetime I've played probably 10,000 hours of basketball, a sport that may well be harder on the feet, knees, and back than any other. (Can't play hoops any more, since this swelling business started. Only time I get to feel that hoops feeling these days is in the occasional dream.) I blew out my knee skiing 12 years ago, and had surgery to repair my ACL. So as far as I was concerned, my problems with swelling was just a symptom of worn-out joints -- and maybe some arthritis, which runs in my family.

Then I came across this, about a study positing a link between inflammation and panic:

Background: Proinflammatory cytokines have been reported to be elevated in individuals experiencing chronic stress as well as in those with major depressive disorder. Much less is known about cytokines in anxiety disorders such as posttraumatic stress disorder (PTSD) and panic disorder (PD). We hypothesized that PD and PTSD would be associated with a generalized proinflammatory cytokine signature...

Results: Individuals with primary PTSD or PD had significantly elevated median peripheral cytokine levels for 18 of 20 different cytokines compared to age- and gender-matched healthy controls...For men and women, 87% of anxiety patients had six or more detectable levels of these proinflammatory cytokines, compared with only 25% of controls...

Conclusions: These findings suggest that a generalized inflammatory state may be present in individuals with PD or PTSD.

Now I wonder: Could there be some link between panic and the inflammation I experience? Might panic, or my genetic predisposition to it, have some role in my bouts of mystery swelling?

How about you other panic sufferers: Have you experienced inflammation you can't readily explain?