Appropriate laboratory tests.

[Kirth]

Hi all, newly diagnosed Type 1.5 (LADA).
Has anyone had any difficulty getting the appropriate laboratory test to support their diagnosis.
I'm a Biomedical Scientist (Microbiology) and I like many other health professionals was not aware of (LADA), I just assumed that as I've just turned 60 I was Type 2.
Needless to to say as soon as I got the diagnosis I had to research it myself.
I found this very interesting scientific paper Recognizing and Appropriately Treating Latent Autoimmune Diabetes in Adults which has given me some helpful insights.

My GAD 65 antibodies have come back negative, but they are not always positive.
I was told that they do not do C-peptide or the other autoantibodies.
I would have though that C-peptide levels would provide good feedback on how many of my islet cells are still working and the progression of the disease.
Has anyone else been told by the diabetes clinic that they don't do C-peptide tests?

 

[mikeydt1]

yes told the same and have been labelled type 2 and of course can't get medications to even work.

bets there are loads out there who have been labelled t2 without appropriate testing.

i only found out from this site about the testing what should be done so why isn't it been carried out?

 

[Docb]

As a retired scientist, not biomedical, I am also a bit bemused by the idea that guesswork is considered to beat measuring things when it comes to diabetes diagnosis.

Good job we did not do things that way when I worked in the nuclear industry.

 

[grovesy]

Well there are more Types than those 3 , the last research I saw reported that there are more than 50 different types, this was from the Exeter team.

 

[Becka]

I have twice had a C-Peptide and GAD antibody test, but not the other antibodies.

The first time was on diagnosis, I guess because I was not overweight and would have been considered a low diabetic risk at that time. My results must have been normal as I was classed as type 2 and put on Gliclazide. As that stopped working I asked my G.P. for those tests (at the time unaware I had already done them) and they agreed.

That said, it is obvious C-peptide is an uncommon test. In my borough all blood tests are done through three test centres by the local hospital trust. Two at the major hospitals in the very north of the borough, and a local centre near where I live in the south.

After looking through the reference book my local centre had to call in to ask what colour phial is needed for C-peptide, then said they cannot perform it as the sample needs to be kept on ice and they did not have that facility. So I had to go to one of the hospitals, and even they had to go away to find out what to do.

When the results came back I was told to book an appointment with the practice pharmacist. This turned out to be because those tests came back normal. so their only concern was my high HbA1c. The pharmacist was insistent my high levels were due to me stopping taking Gliclazide, despite me saying it stopped working and despite the high glucose readings when taking it, which they dismissed as meaningless for being a spot test. But then this is the same person who when I first asked about my levels in April said a reading of 30 was impossible.

Fortunately I had a G.P. appointment lined up the following day anyway, and when I explained all this to them they accepted that Gliclazide was the answer, but again said my C-peptide level was normal. As they did not know what to prescribe they went to consult with my usual G.P. When they got back to me I was told my C-peptide was actually normal for a normal fasting glucose reading, but was low for my levels.

That is were things are at the moment, as the G.P. referred me to the diabetes clinic and I am still waiting for that appointment.

From that experience I would say that phlebotomists do not perform the test with any sort of regularity that they do not know what to do, some are not even equipped for it, and it is not even in the guidebook.

And whilst G.P.s do know they can order it, and are willing to do so, they only understand it in the more binary terms of type 1. That is it is either very low (T1) or not (T2 unless T1 antibodies).

But I do not know if they can or would do the other antibody tests as I never asked for them. I was only told, when I first asked for advice, to request GAD and C-peptide so that is what I did. It is only reading up afterwards I fund out there were other antibodies.

Mind, it is also possible that a GAD test is a panel that also tests for the others? I never knew to ask when I got the results. But if the C-peptide is enough (hopefully!) for a better diagnosis then I suppose it does not matter anyway.

 

[Kirth]

Oh no! I have something in common with Theresa May!
Thank you @grovesy for pointing me towards the Exeter team.
Very interesting article and confirms my surmise that C-peptides are a key test in LADA diagnosis.
It seems the C-peptide test is has stringent sampling requirements (must be frozen and received in the lab within 24 hours), still I cannot believe it is not available in London.

 

[Becka]

But I live in London?

 

[Kirth]

Managed to track down the lab test directory for Barts trust at the RLH.
The test is available but you have to be referef by your team/GP.
They have a 2 hour sample time limit so I will have to go there to be tested.
The clinic could have told me this instead of just saying 'we don't do them'.
To think I work in a path lab and have had to track this information down myself, I can see why many lay-people are left floundering.

 

[DaveB]

Hi. I've been down the same route and still travelling. As my GP refused to accept that I might be T1, I had GAD and C-Peptide tests done by Medichecks 5 years ago. I had a further C-Peptide test done in London last year by them which showed further reduction in my insulin down to near T1 level. My original GAD was negative. I asked my DN in June this year for an 'NHS' C-Peptide to check my diagnosis as I wanted to be listed as T1 if possible to help get a free CGM in the future; she said OK and did refer me. I have a phone call with the Diabetes Clinic in October so we'll see - I'm not hopeful. BTW Medichecks have a 20% discount offer currently (I'm not connected with them but they seem to be the only private clinic available for lab tests in the UK that don't need a referral). I believe the NHS usually uses Exeter for it's tests.

 

[Becka]

Our trust uses Viapath for tests — which is a service they founded so I am not sure where it sits on a scale of public to private — but they list C-peptide as one they offer.

User account

www.viapath.co.uk

Checking that also answered my wondering over whether GAD antibody testing is done as a panel: "These autoantibodies are tested for by enzyme-linked immunoassay and is only able to be requested as a complete panel.". Although that seems to test three of the five antibodies.

Glutamic Acid Decarboxylase (GAD) Antibodies

www.viapath.co.uk

And, on an personal note, that in turn led me to a fascinating line on Wikipedia stating that "Cyclosporine A, an immunosuppressive agent, has apparently halted destruction of beta cells (on the basis of reduced insulin usage), but its kidney toxicity and other side effects make it highly inappropriate for long-term use."

I used to take Ciclosporin, until I had to stop due to it causing kidney damage. Given everything I have read suggests a shorter gap to loss of function compared to when I was diagnosed, this seemingly explains that.

Mind, the way my body works it comes as little surprise to know it was playing organs off against each other. The tattle-tale kidneys just had to go and tell my blood tests so they could get the competition excluded.

 

[Kirth]

Viapath are wholy owned susiduary of Serco and do the pathology testing for most of South London NHS trusts, it's name was changed after it was caught double charging for tests.
I was diagnosed with uveitis two years sgo which an autoimmune disease of the eyes, so my body has already been fighting itself.
I am a Biomedical Scientist and yes tests can come as individuals or a panal depending on the manufacturet and the stability of the tests and the frequancy required.
It may OK to have a full panel of test even if one has short shelf life if you are using them fast enough.
Test with special requirements and short shelf lives will be centralised in more specialist centres. That doesn't help people in more rural areas and if the tesrs are not in the directory of your local path lab your GP probably won't enve knoe they are available.

 

[Docb]

@Kirth, I might have differences with you on the fructose issue, but I find your insights into the realities of testing very useful.

People tend to assume that you give a sample, it goes somewhere instantaneously, where somebody presses a button and out comes a number that is sacrosanct and tells you everything. Having run QA labs in the past I know that is rarely the case. A lot more goes on in the background than most appreciate and it good to have that re-inforced by somebody currently doing it on a daily basis.

 

[Robin]

@SB2015 has recently had a C-peptide, via a urine sample, see here.

C Peptide result

I had a c peptide test, from a urine sample, recently as I was interested to know if I had any Beta cells still lurking and mucking around when least expected. The value came back as 0.08 which is severe lack of insulin. However I have no idea whether that figure means whether there are still...

forum.diabetes.org.uk

She is away from the forum for a few days, I think, so may take a while to see this thread.

 

[Becka]

Viapath has never been wholly owned by Serco. It started out with them as commercial partner to Guy's and St Thomas' Hospitals when they spun off their pathology service in 2009. They then joined with KingsPath, the pathology service of King's College Hospital in 2010.

Serco were the majority partner in the beginning, though I do not know the split, however the three ended up being equal partners for most of its existence. Until this summer when the two N.H.S. trusts bought out Serco's share.

 

[DaveB]

Sadly Viapath don't do private tests; only thru the NHS.