I've just been to my GP and he says that my last blood test shows raised MPO (which it has in the past too) but he didn't explain what it means except to say that 'it was to do with my vasculitis' and to be honest I didn't feel well enough go into it with him.
Can anyone enlighten me please? I would be very grateful.
Ally
From Wikipedia: "Myeloperoxidase (MPO) is a peroxidase enzyme that in humans is encoded by the MPO gene.[2] Myeloperoxidase is most abundantly expressed in neutrophil granulocytes (a subtype of white blood cells).[3] It is a lysosomal protein stored in azurophilic granules of the neutrophil. MPO has a heme pigment, which causes its green color in secretions rich in neutrophils, such as pus and some forms of mucus."
Don't understand a word of it though. Maybe you could look at the article yourself to find out more:
en.wikipedia.org/wiki/Myelo...
Yes I read this too but was more confused - if that's possible!
What type of vasculitis have you been diagnosed with AllyGY2013? Is it MPA?
GPA/WG is what my rheumy believes I have. I see him annually In October. GP says a copy of results have been sent to rheumy.
MPO is an enzyme that is found in the white blood cells that are called neutrophils (there are several different white blood cells). It is almost always raised in MPA, tends to fall when the treatment is working and may rise again if the treatment isn't enough to control the vasculitis but it isn't 100% accurate for monitoring treatment. It does tend to be an indicator of how active the MPA is though.
There are a whole range of blood tests for these sorts of illness, the others are mostly autoantibodies, ANCA, and when you put the results all together it can make one illness more likely than another. It is pretty complex - and I'll lay odds your GP didn't know what it meant either other than it was to do with the vasculitis! Does this help?
Yes it does thank you.
it stands for Myelo Peroxidase the significance of it, is that MPO+ is "usually" an indication of MPA (Microscopic Polyangiitis ) whereas Proteinase 3 is an indicator of C ANCA, which is "usually" associated with Wegeners Granulomatosis ( GPA) in some cases there is an overlap between WG and MPA.
Thanks for that.
I was ANCA positive a year ago, that's when rheumy said Wegeners but no longer ANCA positive but MPO seems to have been raised throughout although only told that today.
Won't get to see rheumy until October and my last appointment was a total waste of time he just gave me a cursery check, noted eyes and mouth still dry, didn't listen to my concerns and just said 'keep taking the meds' (plaquenil and anti inflammatory) and that was that. I am lucky that my GP surgery has 2 GPs with interest in rheumatology who try to support me, but the one which I see most of will be retiring in the not too distant future.
MPo and PR3 ANCA testing
P anca positive with mpo negative 
P-ANCA MPO positive since 2008. 
ANCA MPO and Systemic sclerosis positive - Suddenly ESR 93
P-ANCA and MPO - not yet diagnosed and extremely anxious
