GAD 65 test
- Thread starter petemoss
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Hi @petemoss and welcome to the forums.
Two thoughts from me
1) What's a PA? I am guessing a doctor rather than a personal assistant
2) My understanding as a T1 for 52 years is that the antibodies don't necessarily show up for T1s, and certainly not after your insulin production has been destroyed.
Having said that, they did a recent study in Scotland where they did cpeptide tests on all their patients who had been T1 for more than 3 years, and some were reclassified as T2 or MODY, including several cases where people came off insulin (13 out of 860).
A third thought is that you could ask for a cpeptide test.
Two thoughts from me
1) What's a PA? I am guessing a doctor rather than a personal assistant
2) My understanding as a T1 for 52 years is that the antibodies don't necessarily show up for T1s, and certainly not after your insulin production has been destroyed.
Having said that, they did a recent study in Scotland where they did cpeptide tests on all their patients who had been T1 for more than 3 years, and some were reclassified as T2 or MODY, including several cases where people came off insulin (13 out of 860).
A third thought is that you could ask for a cpeptide test.
Marie 2
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@EllieM A PA is a physicians assistant. It is a step below a doctor. Just a little less schooling.
I would ask for a c-peptide to see how much insulin you are making. Low or low normal are a sign of being a type 1, because you are lacking insulin production. High or high normal are a sign of being a type 2, because you make extra because you are insulin resistant and trying to make up for it.
Some type 1's test negative on antibody tests, and they don't know why. Plus there are more antibody tests than a GAD test. It's just a majority of people test positive on the GAD test and because of costs a lot of countries only test for that one. I know my endo that finally diagnosed me right ordered all the tests, but they did the GAD test first and since I was positive the lab literally said the others weren't done since I was positive on the GAD one. Also after some point in time antibodies can disappear, although I think that is a longer time period. I know on another site there was a discussion warning people that Medicare required a positive antibody test and some old timers weren't testing positive anymore. But that a C-peptide was accepted instead. (Medicare is US that you qualify for when you reach 65).
And then you run into that not all doctors are familiar with type 1. Really. Just 15 years ago an endo who is supposed to be a specialist told me I was a type 2 when I questioned him about being a type 1, because I had an uncle that was a type1. He just goes nope, you're a type 2 and never even tested me. My GP at the same time said the same thing and told me none of the medications would work at all if I was a type 1. That's just not true. It wasn't until I switched doctors who sent me to a new endo who tested me right away that I was finally diagnosed right. Just recently here a guy in his twenties was sent home from emergency and was told he was too old to be a type 1 when he asked and was sent home. Only to be called the next day that he had type 1 and get back there. At least they tested him. And just the other day a new doctor I saw when I told him I was a type 1 he said I must have seen an awful lot of tech changes through the years. Obviously assuming I had gotten it when I was younger.
A diabetic educator here is a type 1 that doesn't have the antibodies..........but doesn't make insulin, some doctors are better than others, ask for a C-Peptide test.
I would ask for a c-peptide to see how much insulin you are making. Low or low normal are a sign of being a type 1, because you are lacking insulin production. High or high normal are a sign of being a type 2, because you make extra because you are insulin resistant and trying to make up for it.
Some type 1's test negative on antibody tests, and they don't know why. Plus there are more antibody tests than a GAD test. It's just a majority of people test positive on the GAD test and because of costs a lot of countries only test for that one. I know my endo that finally diagnosed me right ordered all the tests, but they did the GAD test first and since I was positive the lab literally said the others weren't done since I was positive on the GAD one. Also after some point in time antibodies can disappear, although I think that is a longer time period. I know on another site there was a discussion warning people that Medicare required a positive antibody test and some old timers weren't testing positive anymore. But that a C-peptide was accepted instead. (Medicare is US that you qualify for when you reach 65).
And then you run into that not all doctors are familiar with type 1. Really. Just 15 years ago an endo who is supposed to be a specialist told me I was a type 2 when I questioned him about being a type 1, because I had an uncle that was a type1. He just goes nope, you're a type 2 and never even tested me. My GP at the same time said the same thing and told me none of the medications would work at all if I was a type 1. That's just not true. It wasn't until I switched doctors who sent me to a new endo who tested me right away that I was finally diagnosed right. Just recently here a guy in his twenties was sent home from emergency and was told he was too old to be a type 1 when he asked and was sent home. Only to be called the next day that he had type 1 and get back there. At least they tested him. And just the other day a new doctor I saw when I told him I was a type 1 he said I must have seen an awful lot of tech changes through the years. Obviously assuming I had gotten it when I was younger.
A diabetic educator here is a type 1 that doesn't have the antibodies..........but doesn't make insulin, some doctors are better than others, ask for a C-Peptide test.
- C-Peptide
While most tests check for antibodies, this test measures how much C-peptide is in a person’s blood. Peptide levels typically mirror insulin levels in the body. Low levels of C-peptide and insulin can point to T1D. - Insulin Autoantibodies (IAA)
This tests looks for the antibodies targeting insulin. - Insulinoma-Associated-2 Autoantibodies (IA-2A)
This test looks for antibodies mounted against a specific enzyme in beta cells. Both the IA-2A and GADA tests are common T1D antibody tests. - Zinc Transporter 8 (ZnT8Ab)
This test looks at antibodies targeting an enzyme that is specific to beta cells. - Islet Cell Cytoplasmic Autoantibodies (ICA)
Islet cells are clusters of cells in the pancreas that produce hormones, including insulin. This test identifies a type of islet cell antibodies present in up to 80 percent of people with T1D. - Glutamic Acid Decarboxylase Autoantibodies (GADA or Anti-GAD)
This test looks for antibodies built against a specific enzyme in the insulin-producing pancreatic beta cells.
Hi. There is real confusion out there amongst the medics about 'T1' Few know that viruses can cause beta cell destruction with the same results as antibody destruction. In this case a GAD or other antibody test will be negative. A C-peptide test is therefore essential. This test is not very reliable, however. My C-Peptide is just above the T1 level but I have all the symptoms of very low insulin production and my endo is treating me as a T1 even though as he says the C-Peptide doesn't prove it. Also the urine C-Peptide gives different results for the plasma test. We need better tests and more knowledge amongst the medics.
