Specialist immunology tests

P

Pjs191184

Member
My diagnosis is still baffling the doctors.

- was hospitalised with DKA in March 2024
- My c pep results non fasting - super low at 44, which is severe insulin deficiency
- Antibodies are negative
- CT scan of my pancreas is negative and clear

Now I’m going for specialist immunology blood tests (that will be sent to London).

I’ve been diagnosed as T1 as I went from fine to terrible, and based on my c pep score. And super glad my doctor is being so thorough.

A medical mystery so only the next test to figure out what caused this!

Anyone been in the same boat? I’ve found it quite fascinating!!
 
Pjs191184 said:
A medical mystery so only the next test to figure out what caused this!
Click to expand...
Sorry but I’m confused, what is the mystery? Sounds clear that you’re t1 as producing very little insulin and no damage to pancreas.
 
Pjs191184 said:
Now I’m going for specialist immunology blood tests (that will be sent to London).
Click to expand...
Probably just testing another antibody, it’s quite normal standard process for these tests to be sent away as they need to go to a lab that can process the test. I was tested for 2 antibodies at the same time alongside the cpeptide
 
Or MODY perhaps? I remember you had/have quite high meal ratios @Pjs191184 so maybe they’re thinking you’re an unusual kind of Type 2 who has lost insulin production very early?
 
Lucyr said:
Sorry but I’m confused, what is the mystery? Sounds clear that you’re t1 as producing very little insulin and no damage to pancreas.
Click to expand...

But the lack of antibodies is strange - if they were all tested, that is.
 
Inka said:
But the lack of antibodies is strange - if they were all tested, that is.
Click to expand...
Not really, at least 5% of type 1s test negative for antibodies, estimates vary depending on which antibodies were tested, for some the negative rate is much higher.
 
Lucyr said:
Not really, at least 5% of type 1s test negative for antibodies, estimates vary depending on which antibodies were tested, for some the negative rate is much higher.
Click to expand...

I wonder why? That is, do they have very short-lived antibodies or do they never have any at all? I still had antibodies 25 years after diagnosis. It’s weird how it can be so different for different people.

I think the OP said her diabetes came on very quickly, which does suggest Type 1 to me, a non-medical person.
 
Inka said:
I wonder why? That is, do they have very short-lived antibodies or do they never have any at all?
Click to expand...
I’d add in testing and the established normal ranges won’t be perfect into the list of reasons too, a 95% confidence is usually seen as pretty good
 
Lucyr said:
Probably just testing another antibody, it’s quite normal standard process for these tests to be sent away as they need to go to a lab that can process the test. I was tested for 2 antibodies at the same time alongside the cpeptide
Click to expand...
I was tested for 4 antibodies twice and cpep twice, the lack of antibodies and like Inka mentions my rapid decline is what they are trying to figure out. Apparently my HBAC1 was normal in Feb and then terrible in March. Having as low cpep results with no antibodies in such a short space of time is what they are trying to figure out.

Apparently this specialist test will check for much rarer antibodies.
 
Lucyr said:
Not really, at least 5% of type 1s test negative for antibodies, estimates vary depending on which antibodies were tested, for some the negative rate is much higher.
Click to expand...
Is there any chance of improvement if they have no antibodies? Have you heard of that? Sorry new to this and interested to know!
 
Pjs191184 said:
Having as low cpep results with no antibodies in such a short space of time is what they are trying to figure out.
Click to expand...
T1 can come on suddenly like that, the presence of antibodies confirms it’s T1 but the absence of them doesn’t rule out T1. Other circumstances are usually used to decide T1 or not eg DKA, sudden onset and low cpeptide. Not sure why your team are doing so many tests when there doesn’t appear to be any question about your type.

It’s extremely unlikely you’ll recover and start making enough insulin yourself that you’d not have to take it. My cpeptide is higher than yours and antibodies only 1 was barely positive the rest negative, and been told will need to be on insulin for life as not taking it when not producing much of your own insulin and have had DKA is too high
 
Yes, the sudden onset of Type 1 is one of the signs, I think. There’s a critical point reached when there are no longer enough beta cells to control blood sugar. They also look at age, BMI, any weight loss and ketones. I don’t think they routinely test for antibodies as usually the type is obvious. Of course, sometimes the tests do need doing.

Sorry, but I would also assume there won’t be any improvement @Pjs191184 If you’re unable to make enough of your own insulin, you’ll need exogenous insulin.
 
Lucyr said:
T1 can come on suddenly like that, the presence of antibodies confirms it’s T1 but the absence of them doesn’t rule out T1. Other circumstances are usually used to decide T1 or not eg DKA, sudden onset and low cpeptide. Not sure why your team are doing so many tests when there doesn’t appear to be any question about your type.

It’s extremely unlikely you’ll recover and start making enough insulin yourself that you’d not have to take it. My cpeptide is higher than yours and antibodies only 1 was barely positive the rest negative, and been told will need to be on insulin for life as not taking it when not producing much of your own insulin and have had DKA is too high
Click to expand...
Thanks for your valuable reply x
 
Inka said:
Yes, the sudden onset of Type 1 is one of the signs, I think. There’s a critical point reached when there are no longer enough beta cells to control blood sugar. They also look at age, BMI, any weight loss and ketones. I don’t think they routinely test for antibodies as usually the type is obvious. Of course, sometimes the tests do need doing.

Sorry, but I would also assume there won’t be any improvement @Pjs191184 If you’re unable to make enough of your own insulin, you’ll need exogenous insulin.
Click to expand...
Thank you x
 
Inka said:
I wonder why? That is, do they have very short-lived antibodies or do they never have any at all? I still had antibodies 25 years after diagnosis. It’s weird how it can be so different for different people.
Click to expand...
Maybe antibodies that aren't tested for? Or maybe in some people the beta cells (or whatever) are eliminated and the antibodies contract, but in others enough stick around?
 
I think in some cases (where all the beta cells have been splatted) T1s who may have tested antibody-positive during the process can test negative, because there are no longer any beta cells to have antibodies for.

In other cases (including Joslin 60-year medallists), there seems to be an ongoing cycle of beta cell appearance / antibody destruction for decades.

T1 antibody tests tend to have fewer false negatives nearer the time of diagnosis. But my understanding is that ‘no antibodies’ doesn’t rule out T1.

It’s one of the reasons why in T1 antibody testing is a clue, but it’s not definitive in and of itself. It forms part of the overall clinical picture.
 
You must log in or register to reply here.
Back
Top