Keep in mind that AAG (autoimmmune autonomic ganglionopathy) is NOT the only type of ganglionopathy. You can have damage to the dorsal root ganglia and not have damage to the autonomic ganglia. This blood test is just for one type of ganglionopathy...but an important one if you have dysautonomia.

The test itself won't determine if IVIG will help. It is a diagnostic lab to determine the ganglionopathy. It is still unknown whether the IVIG will help (until you try it), but it is one of the conditions that IVIG has had good results.

They are still not even sure WHY the IVIG helps many people with different types of neuropathy...they don't know the exact mechanism of action. They have ideas how and why it works, but it's not defined just yet.

I personally, have had good results with IVIG for my ganglionopathy...but only certain symptoms. Most of my damage is permanent.