Has anyone else been told they no longer meet the Type 1 Diagnostic criteria?

Some people with T1D are negative for GAD65 (GADA) but positive for other antibodies. But the majority are not. [1,2]

A small percentage (~5–10%) of people with clinically typical T1D are negative for all known antibodies — sometimes called “idiopathic type 1 diabetes.” This is usually called type 1b diabetes. These both have very short honeymoon periods. [3]

There is also MODY (not antibody induced), LADA (same as type 1 but slower - eventually may test positive for GAD65).

Additionally, Type 2, Gestational (pregnancy) and neonatal (babies).

This is why it can be quite complicated to understand at the get go which type you have when you're not injecting a lot.

Given this and you have a smooth profile for 10 years it would suggest not typical type 1 and they seem to be ruling out LADA - but it's important to understand what it is at least.

Type 1 diabetes can be diagnosed by other autoantibodies although these tend to fall years after diagnosis whereas gad65 persists at a lower value due to its presence in the gut and the brain. [2]

At 24 years of T1D my gad65 is 40 IU/mmol (but it becomes less about antibodies and more about how well trained t cells are at this side of diabetes). I'm not sure what the units are on yours? If it's 5IU/mmol then that is normal range levels.

I think a test for MODY is the most appropriate thing right now, strange that they haven't done it this far into diagnosis. Although most type 1s don't even get antibody tests so a lot of corner cutting happens. But keep in mind LADA and type 2 too if the result comes back negative.


Sources:
1. Catherine Pihoker, Lisa K. Gilliam, Christiane S. Hampe, Åke Lernmark; Autoantibodies in Diabetes. Diabetes 1 December 2005; 54 (suppl_2): S52–S61.

2. C L Williams, R Fareed, G L M Mortimer, R J Aitken, I V Wilson, G George, K M Gillespie, A J K Williams, The BOX Study Group , A E Long, The longitudinal loss of islet autoantibody responses from diagnosis of type 1 diabetes occurs progressively over follow-up and is determined by low autoantibody titres, early-onset, and genetic variants, Clinical and Experimental Immunology, Volume 210, Issue 2, November 2022, Pages 151–162

3. Jay S. Skyler; Characterizing Subgroups of Type 1 Diabetes. Diabetes 1 November 2014; 63 (11): 3578–3580.

Hi
I was a weird type 2 for 25 years before I got tested for MODY
Diagnosed at hnfa4 MODY 1 a couple of years ago
Try reading diabetes genes.org & see if anything relates while you’re waiting for the test
Supposedly runs in families but nobody else in my family have any type of diabetes
Good luck hope you get sorted

lovinglife said:

Hi @blackholefox & welcome to the forum

Could you provide your source for the information above, particularly
*Some people with T1D are negative for GAD65 (GADA) but positive for other antibodies. But the majority are not.

*A small percentage (~5–10%) of people with clinically typical T1D are negative for all known antibodies — sometimes called “idiopathic type 1 diabetes.” This is usually called type 1b diabetes. These both have very short honeymoon periods.

And

Type 1 diabetes can be diagnosed by other autoantibodies although these tend to fall years after diagnosis whereas gad65 persists at a lower value due to its presence in the gut and the brain.

Thank you

Click to expand...

Isn't all this just common knowledge in T1D shouldn't need a citation to obvious stuff. The % is debatable but only depending on what country you're from. Type 1b is more common in some African nations. And a fall in autoantibodies is also obvious as the beta cells have been destroyed but gad65 remains expressed as an enzyme in the gut and brain and so leads to life long inflammation in type 1s so is an outlier from the other autoantibodies. That being said the memory b cells that produce said autoantibodies remain and so reactivation can happen which prevents any meaningful regeneration capacity.

The test requited by my insurance to confirm type 1 (and cover pump supplies) was C-Peptide. And mine was undetectable.
It was my understanding that antibody tests cannot diagnose type 1. I found this piece. I didn’t see a date though.