I suspect that the Test is to see if or how many Islets you have in the Pancreas.
The Islets Of Langahan are the ones responsible for making Insulin, those are the ones in Type 1 that break, because we have an autoimmune condition.
If it is "negative" I suspect your like me in the fact that everything is packed up, so you now have to do the job of your pancreas by injecting insulin and monitoring BSL, like your doing now
PS forgot to add I'm not medically trained, found out the above by doing a search
