My C4 is normal too.
C4a (note the ‘a’ for activated) is usually very high in CFS and lots of people with CFS have POTS. As you know complement is associated with inflammatory states.
This shouldn’t be confused with CD4 though, an immune supression marker!
CD4/CD8 ratio is abnormal in CFS also usually.
Chronic inflammation can damage lining to blood vessels and we know what that could cause.
I have very high cytokines and chemokines and high natural killer cell count.
Would be interesting to measure markers of inflammation/infection in people who have CCSVI or think they may have it.
Plus the POTS people. 🙂