ANCA question

[liquoricet]

I think my GP is suspecting I have vasculitis or lupus. I wrote a really long message but thought I'd keep it succinct.

My question is, do the labs in the UK only screen for MPO & PR3 if the ANCA test was positive?

Thanks

[citygirl1234]

Hi,

There are two main ways that an ANCA test can be run - ELISA or immunofluorescence. The former is considered best practice and gives a quantifiable PR3 and MPO result. The latter looks at the staining pattern. Some labs just do the former, others do both. See vasculitis.org.uk/about-vas... for more information about the test. There is usually an accompanying note with the blood test result that states the method(s) used.

If your ANCA test is done by the ELISA method and it is negative, there will still be a PR3 and MPO value, it will just be below the threshold for positive. (There is a range used). It’s not like an ANA test, where they often only check for anti ds-DNA if the ANA result was positive (which is associated with lupus).

FYI ANCA tests are fairly specialist and can take longer to come back than other blood tests e.g. FBCs, even within a hospital setting.

It’s also worth highlighting a few things about the ANCA test and vasculitis in general:

(1) Neither a positive ANCA test nor a negative test by itself confirms or excludes ANCA vasculitis. The three ANCA vasculitis (“AAV”) conditions (GPA, EPGA & MPA) are associated with the Anti Neutrophil Cytoplasmic Antibodies but you can still have one of those three conditions and be ANCA negative. The only way to get vasculitis confirmed or excluded is via a holistic assessment by a specialist doctor with knowledge of vasculitis. Call or email vasculitis UK and they can help you find one. (vasculitis.org.uk/contact). Some of the vasculitis specialists are also lupus specialists (as both are similar(ish) autoimmune conditions), which I think is probably who you need to see so you can be assessed for both.

(2) Positive ANCA tests can also be associated with other conditions e.g. Ulcerative Colitis (so just like an ANA test result, they need to be put into context).

(3) There are lots of types of vasculitis and some people do have a form of vasculitis and SLE / lupus, so you may also want to ask your doctor to rule out the other types of vasculitis as well as some of them have similar symptoms. See vasculitis.org.uk/about-vas... for more information.

I hope this helps, best of luck to you.

[liquoricet in reply to citygirl1234]

Thank you, that is really helpful. It's unclear from the test results (which I've viewed on patient access which method they've used). However, all the results say 0.2 for ENA and ANCA so perhaps the means they were done at once.

My GP has been stabbing in the dark as we've discovered I've high crp/ESR/platelets but after lots of tests (abdominal ultrasound, chest x-ray and blood tests) still don't know why. Thankfully I'm not very symptomatic (slight joint pain) but that makes a diagnosis harder. I am going to give up googling and see what the general consultant says at my hospital appointment.

[citygirl1234 in reply to liquoricet]

You’re welcome. Sometimes it takes a while to work out what’s going on. (It certainly did for me). Sounds like your GP is determined to get to the bottom of it though and is willing to go through the full list including the rare conditions that often get missed, which is good! Hang in there, and ask as many questions as you need.

If lupus or ANCA vasculitis are suspected, your GP should also be doing a urine protein test as these conditions can affect your kidneys. (Protein often shows up in the urine before bloods change and if you do have kidney problems, you want to catch them early). If they ran an ANCA test they should also have done this.

If you want advice on the lupus side of things, Lupus UK are really helpful too (lupusuk.org.uk/ or search for Lupus UK on this site to find their forum).

[liquoricet]

Thank you, that's really helpful. I've looked at the lupus forum too.

My GP did do the urine protein tests and they were negative. (Urine protein electrophoresis and serum protein electrophoresis?) Is that right?

[citygirl1234 in reply to liquoricet]

You’re welcome. Excellent, glad to hear (that is right).

[philtw]

hi

I have GPA and ANCA tests for PR3 in my case

This affected my lungs as i had coin lesions

30yrs ago i had PAN which affected my kidneys.

[EGPAGuy]

I have EGPA and have never tested positive to an ANCA test-its not always a reliable marker. For a diagnosis you need to see a specialist..depending on your location this forum will likely be able to give you contacts to get your GP to refer you. Be persistent..Vasculitis and I am sure the same applies to Lupus are better treated when diagnosed early.

[liquoricet]

Thank you

[Suzi70 Administrator Vasculitis UK]

this page on the VUK website explains ANCA vasculitis.org.uk/about-vas...

ANCA blood tests are not usually routine it is a more expensive blood test and having a positive ANCA test doesn’t necessarily mean you have vasculitis. But further blood tests should be done and also a good doctor would look at all signs, symptoms and how the patient is feeling.

[Investigator1]

Hi liquoricet. ANCA and the tests surrounding it are a complete bag of spanner’s, they indicate certain things but not everything. My ANCA reading is 4 ish but my consultant says even after all the treatment that’s what it could be naturally.