confused with anti body test?

[Peapod87]

Hey all, so saw the diabetic dept at hosp today for a catch up as I newly diagnosed etc etc and I asked about the results for my anti body test as it was done over 2 months ago and hadn't heard back. She went to find out and said one of them came back negative which apparently happens to 30% of the tests and the other one came back very positive. I know there's no getting away from the fact I am type 1 but I just didn't get it? Anyone had same results?

Thank you

 

[Robin]

The antibody test that measures GAD, I know is notoriously unreliable. It shows positive while you are in the process of losing your beta cells, but once your immune system has destroyed them and calmed down, it then shows negative.

 

[Peapod87]

Ah I see I mean she didn't say it was anything to worry about its just after she mentioned it I wish I asked more. Thanks Robin

 

[Northerner]

Never had the tests done myself, although my consultant kept saying he was going to arrange them! I've heard the same from others, that the tests aren't ultra-reliable. I think a C-peptide test gives a better indication because it measures how much actual insulin you are producing - very low = Type 1/LADA, but high = Type 2, as Type 2s often produce lots more insulin than non-diabetic people as the pancreas tries to compensate for insulin-resistance.

How are things going for you now, @Peapod87 ? 🙂

 

[everydayupsanddowns]

One of the reasons why multiple antibodies are tested for is simply because these tests are nothing like as cut-and-dried as we would hope them to be. You can get T2s with antibodies, and T1s (who have been disgnosed for some time) with very few. It's all a bit complex and confusing. Even cPep is similar, in that you can have people with T1 for 75 years who are still producing *some* of their own insulin, despite having been insulin dependent all that time.

The new NICE guidance NG17 covers this topic beginning at page 80 with recommendations at page 102 section 5.6:

1. Diagnose type 1 diabetes on clinical grounds in adults presenting with hyperglycaemia, bearing in mind that people with type 1 diabetes typically (but not always) have one or more of:

• ketosis
• rapid weight loss
• age of onset below 50 years
• BMI below 25 kg/m2
• personal and/or family history of autoimmune disease. [new 2015]

2. Do not discount a diagnosis of type 1 diabetes if an adult presents with a BMI of 25 kg/m2 or above or is aged 50 years or above. [new 2015]
3. Do not measure C-peptide and/or diabetes-specific autoantibody titres routinely to confirm type 1 diabetes in adults. [new 2015]
4. Consider further investigation in adults that involves measurement of C-peptide and/or diabetes-specific autoantibody titres if:

• type 1 diabetes is suspected but the clinical presentation includessome atypical features (for example, age 50 years or above, BMI of 25 kg/m2 or above, slow evolution of hyperglycaemia or longprodrome) or
• type 1 diabetes has been diagnosed and treatment started but there is a clinical suspicion that the person may have a monogenic form of diabetes, and C-peptide and/or autoantibody testing may guide the use of genetic testing or
• classification is uncertain, and confirming type 1 diabetes would have implications for availability of therapy (for example,continuous subcutaneous insulin infusion [CSII or ‘insulin pump’] therapy). [new 2015]

5.When measuring C-peptide and/or diabetes-specific autoantibody titres, take into account that:

• 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]

 

[Peapod87]

So Type 1 is an auto-immune condition where the immune system, for some reason – not fully understood, recognises the beta cells in the pancreas as being unhelpful and need to be destroyed.

Type 2 diabetes is a more complex condition and not Auto-immune

So in type 1 diabetes the body builds an immune response against the beta cells – which is what destroys the cells.

Depending on how strong the response is determins how quickly the beta cells are destroyed (this partly creates the honeymoon period if it happens slowly )

The two types of antibodies that were measured in you are the ones that typically attack the beta cells and the fact that one of them was present shows that this is an autoimmune response and therefore type 1 diabetes and not type 2

This is what my diabeties educator said, kinda makes sense lol.

Thank you for your help tho everyone this really is a very knowledgeable forum .

Not too bad thanks Northener still honeymooning which is good I guess but I worry I'm going to forget what to do when it ends lol. How are you? xx

 

[Northerner]

Not too bad thanks Northener still honeymooning which is good I guess but I worry I'm going to forget what to do when it ends lol. How are you? xx

Good to hear you are ticking along 🙂 Don't worry, you'll soon pick things up when the honeymoon ends 🙂 I'm good, thank you 🙂