My results from Redlabs showed increased Perforin. Their website describes the test as relating to NK cell function: It also says that most PWME/CFS have LOW NK cell function, whereas mine seems to be HIGH. I also now have a positive ANA - although of course others here have pointed out that the titres are not high - 80, with a speckled pattern (non specific). I disagree that this is not important as its only unimportant to have low positive ANA if you don't have symptoms - I clearly do have symptoms. So im just wondering really what High NK cell activity really means. It looks to me like one section of my immune system is overactive, although KDM said the other part was underactive (TH1?) I have to admit that I don't really understand this, and the only information I can find easily on the net related to high NK cell activity is all to do with fertility and miscarriage. Does this mean that my body is desperately trying to kill something (I also have high cytokines - specifically IL8, and high prostaglandins (E2)) What do those of us with HIGH NK cells have in common, if anything? What does it mean if my NK cells are high?