Diagnosis of LADA

Jaxx01 · Sep 17, 2015

Hi all.

Bit of background. ..GD diagnosed 2011 straight onto insulin, then diagnosed Type 2 in 2012.

Tried oral meds, no effect and finally put on insulin (after a long fight with my docs) in feb.

Now today my doc has agreed to do an antibody test after refusing to refer me to the hospital clinic like I requested!

My question is : has anyone had their diagnosis changed purely from having the gad antibody test? What we're your results?

Also, after reading up, I read that the antibody test should be done before insulin therapy :/ does that mean it's pointless?

I just want to make sure I've got the right diagnosis

Ian DP · Sep 17, 2015

I was diagnosed T2 two years ago, this was changed to T1 three months later when I had a GAD test, my GAD was over 2,000. Don't know about GAD test and insulin, hopefully some one else will come along to answer that.

urbanracer · Sep 17, 2015

Jaxx01 said:
Hi all.

Bit of background. ..GD diagnosed 2011 straight onto insulin, then diagnosed Type 2 in 2012.

Tried oral meds, no effect and finally put on insulin (after a long fight with my docs) in feb.

Now today my doc has agreed to do an antibody test after refusing to refer me to the hospital clinic like I requested!

My question is : has anyone had their diagnosis changed purely from having the gad antibody test? What we're your results?

Also, after reading up, I read that the antibody test should be done before insulin therapy :/ does that mean it's pointless?

I just want to make sure I've got the right diagnosis

No it's not pointless but it does have limited value as approx 25% of T1's do not test positive for GAD antibodies. The test itself is not conclusive. My understanding is that it is usually used in conjunction with a C-Peptide test.

http://www.diabetes.co.uk/gad-antibody-test.html

phoenix · Sep 17, 2015

GAD antibodies can persist for many years after diagnosis of T1
http://www.diapedia.org/type-1-diabetes-mellitus/gad-antibodies

Daibell · Sep 18, 2015

phoenix said:
GAD antibodies can persist for many years after diagnosis of T1
http://www.diapedia.org/type-1-diabetes-mellitus/gad-antibodies

...but according to the latest NICE Guidelines, the GAD test is less reliable as the years pass after diagnosis whereas the c-peptide becomes more reliable. Taking insulin shouldn't affect the GAD test, I believe, and even the c-peptide as only the body's insulin creates c-peptide?

phoenix · Sep 18, 2015

Daibell said:
...but according to the latest NICE Guidelines, the GAD test is less reliable as the years pass after diagnosis whereas the c-peptide becomes more reliable. Taking insulin shouldn't affect the GAD test, I believe, and even the c-peptide as only the body's insulin creates c-peptide?

What it actually says is

autoantibody tests have their lowest false negative rate at the time of diagnosis, and that the false negative rate rises thereafter
C-peptide has better discriminative value the longer the test is done after diagnosis
with autoantibody testing, carrying out tests for 2 different diabetes‑specific autoantibodies, with at least 1 being positive, reduces the false negative rate. [new 2015]

This is from a study of antibodies in the UK Golden years(50 years) cohort

Autoantibodies have previously been shown to remain detectable in two thirds of patients during the 10 years after
diabetes onset, and in some cases may increase in titre [9]. Our results now show a remarkable persistence of GADA in long term survivors of type 1 diabetes, both in terms of autoantibody frequency and titre. IA-2A and ZnT8Awere also presentin patients with long-duration diabetes, but at lower frequency than GADA, and with reduced antibody levels

Of course this probably indicates there is still some presence of working beta cells and the people in these long term cohorts are the 'survivors' Recent studies also show that many long term T1s still produce some, tiny amounts of insulin.(hence an ongoing autoimmune destruction, and antibodies)
This is presumably even more likely to be the case in LADA http://link.springer.com/article/10.1007/s00125-013-3017-7#page-1
IAA antibody tests aren't useful after insulin treatment because you can develop antibodies against injected insulin and the test doesn't discriminate between them (they occur more in children anyway)https://labtestsonline.org/understanding/analytes/diabetes-auto/tab/test/

LucySW · Sep 18, 2015

I was changed to LADA from T2 after GAD test.

cz_dave · Sep 19, 2015

Me too.

viv k · Sep 21, 2015

Yes, my diagnosis went from type 2 to type 1 purely on a positive GAD test.

Pilgrim22 · Sep 21, 2015

LucySW said:
I was changed to LADA from T2 after GAD test.

Ditto

notafanofsugar · Sep 21, 2015

They didn't know what type of diabetes I had... couldn't decide (tbh, he probably didn't know!!!) between T1/T2. Eventually went to someone I had more confidence in! x

Diagnosis of LADA

Jaxx01

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