Hi
@Adster good question!
Underlying the immune deficiency diagnosis is an assumption that the definition of Me/CFS is an immune disregulation and/or disorder. I happen to believe it is!
But many researchers clarify it as a range of other disorders such as viral/bacterial infections, Gut microbiome, Lyme Disease, Autoimmune (different from immune) , Neuroimmune and or various brain disorders including HPA dis reg, an infection that has crossed the blood/brain barrier, dysfunctioning ganglia and a range of other suggestions.
I know that patients with ME/CFS are consistently found to have poor NK (Natural Killer Cell) functioining which means we get sicker for longer and are unable to fight off viruses bacteria and parasites like normal people. Sounds like a defunct immune system to me.
So we know these 2 are correlated but the cause is as yet unidentified. I recently visited Griffith University's CFS Health clinic and they are working on research looking at T1 and T2 immune regulation cells as not working properly. They are fairly confident this research will produce some results in the not too distant future that these are key to understanding the disease.
So answer to yr question is it may or may not be relevant. Do you still have the symptoms is probably the key issue?
And further we really wont know until there is a provable diagnostic test. Hope that helps