Sedimentation rate versus CRP count?

[casse]

Anyone know which is more important sed rate, or CRP? And what should a good CRP reading be?

[Annodomini]

My GP and Rheumy are more interested in my CRP than in my ESR. Raised CRP can be a symptom of infections such as sinus infections which I think explains my raised CRP.

[casse in reply to Annodomini]

Thanks been reading and agree it looks like CRP more important. Hard to distinguish elvated CRP from a flair or prednisone withdraw. Will have to do more research.

[HeronNS]

On the Patient website I found this: "The ESR is more useful than serum CRP for diagnosis and monitoring of polymyalgia rheumatica or temporal arteritis and is more frequently elevated during relapse."

patient.info/doctor/acute-p...

[casse in reply to HeronNS]

Great article thank you 😀

[venezia1]

It seems there is not much agreement about this. At my visit to my specialist nurse today I asked this question, and she said that ESR is the most important indicator for rheumatoid, and that CRP is really only useful in indicating possible infections. Hope this helps!

[casse in reply to venezia1]

More I read more confused I get but thank you I guess they're both important hopefully I'm going through withdrawal second day on 30 and not another flair. Have to wait two weeks for the blood work.

[Hidden in reply to venezia1]

Not true! Patients with other forms of Vasculitis can have CRP's as high as 300 because of inflamation not infection.

[Hidden]

I think it varies from patient to patient. Neither are specific for PMR/GCA. They are both general markers of inflamation or infection, CRP is produced by the liver.

Depending on your lab a " normal " CRP is usually under 5 or 10 ( I think the USA values are slightly different. ). Either way they should be used in conjunction with symtoms to assess disease state.

[Annodomini]

My initial CRP was 250. And there was no doubt that I had PMR. It still hovers around 20 which may be a chronic sinus infection which post-dates my PMR.

[DorsetLady PMRGCAuk volunteer]

Don't think either is more important than other. I had both done at beginning of treatment, but over time the CRP was discontinued. This was more noticeable when I changed surgeries, and I think that it was down to the fact that, the CRP samples couldn't be transported to the local hospital within the timescale required for the test to be done.

Somewhere in the recess of my mind, the timescale of under 4 hours for the CRP test seems relevant. I may well be wrong, and if I am, I sure someone will correct me, so I'll apologise in advance!

[Hidden in reply to DorsetLady]

It's ESR that needs to get to the lab quickly 😄

[DorsetLady PMRGCAuk volunteer in reply to Hidden]

Okay thanks. Knew one was - so had 50/50 chance of being right - or wrong. Duh! 😂

[casse in reply to DorsetLady]

Yes, there is a time limit that's why the last two years I get all my lab work done at hospital so they can do it quickly the reports were so different from the other lab and the hospital it was amazing

[DorsetLady PMRGCAuk volunteer in reply to casse]

That's interesting. Must admit I have wondered about that myself.

[SusanEleven]

My rheumatologist has never monitored ESR. Just CRP. Though she always tells me it only indicates inflammation somewhere in the body. Normal labs here are <5. When my PMR was first diagnosed my CRP was 35. Pred tamed the symptoms very quickly and after my first month on pred CRP was normal again. It has gone up and down (11 during a flare and 9 now as my tapering continues) but my doc is focused mainly on my symptoms versus blood test results.

[PMRpro Ambassador]

CRP is a protein made by the liver in response to inflammation. ESR/sed rate measures the speed with which the red blood cells settle to the bottom of a special test tube - that speed is influenced by proteins which are found on the surface of the red blood cells so CRP is also involved in that. If inflammation is present in the body, no matter what it is, then either or both ESR and CRP are likely to be raised - but about 20% of people don't show this response of what are called "acute phase reactants" and their readings remain in the "normal range" whatever is going on. Others have a stubbornly high reading - with little or nothing wrong. Some 95% of the levels in the general population vary between about 5 and 30 - so that leaves a few of us at each end who fill in those little corners of the bell-shaped curve.

Actually, ESR/sed rate has been said by experts for years to be so non-specific it shouldn't be used - it can be raised because of so many different things from a cold to pregnancy! But doctors are very wedded to their lab tests and continue to use them! The best doctors treat the patient and not the lab results!

Studies of patients with diagnoses of PMR and GCA suggested that CRP might be a more reliable monitor - it is affected by other things less than ESR tends to be. But a chest infection can cause a very elevated CRP - even though there is nothing going on with the PMR/GCA (or any other vasculitis). And some patients have seen that their ESR reflectes their symptoms better than CRP - everyone is different and really, it is YOUR "normal" that is important.

The "normal range" depends on the lab, it varies slightly from lab to lab so you always need to look at the figures in brackets after the result which tell you what reference range your lab uses. And a slightly raised level of either on their own shouldn't result in a change in pred dose as a reflex response - another blood test should be done a week later to see if there is a trend. If it is rising or if there are accompanying symptoms of PMR/GCA - that should result in consideration of raising the pred dose but not otherwise until you have waited a bit to see what's going on.

[Doralouise77]

My sed rate has always been relatively normal so my rheumy goes more by my CRP. The day mine jumped drastically I spoke with him and he said it was more likely an infection which it proved to be.

Something I've been trying to figure out is if the different values we see for CRPs are not necessarily lab differences but due to a different type of CRP tested? There is a regular CRP and a highly sensitive CRP (hsCRP) (....and I've just learned today a third one, cCRP, cardiac CRP). The hsCRP is used more as a tool for determining cardiac risk in normal people and the value is lower, desirable under 1 mg/L.....we started ordering this almost 10 years ago at the clinic I worked at as part of a cardiovascular assessment.....whereas the regular CRP is used for assessing chronic inflammation and normals are usually up to 10 mg/L.....so....are some values we're seeing reflective of doctors ordering the hsCRP? which maybe isn't the best one to assess PMR/GCA? or maybe some labs only do one or the other? If you google the difference there's lots of info....but I'm still left wondering about the values reported as to lab difference or test difference....

Cheers

[casse in reply to Doralouise77]

Both of my doctors agreed I should get it done at the hospital not sure if it was the CRP or sed rate because they do it right away at lab it has to be sent out and it doesn't get done in so many hours. I'm sure it was the same test that I always get. I am also able to pull up my lab results usually within 24/48 hrs. on the portal from the hospital where the old lab would take days. Been going almost every three weeks now for two years and they are just great the people at the hospital, I am blessed!

[PMRpro Ambassador in reply to Doralouise77]

I was under the impression the hsCRP and the cardiac one were the same - maybe not. However, one of the links in this suggests that while they are possibly different the assay used is the same and different names are probably pointless. The rest provides some interesting responses to the question if you have the science background (sorry anyone else, it's probably Chinese to you):

researchgate.net/post/Do_yo...

The levels are much lower and mostly you will get ordinary CRP reported as a matter of course - because if it is above 1 the concept of hsCRP be swamped. And actually - anyone with a raised CRP due to inflammation SHOULD be considered as at higher risk for cardiovascular disease and be monitored appropriately (that's my opinion and I shall stick to it).

And nothing changes the fact that every lab has its own "normal range".

[Doralouise77 in reply to PMRpro]

i found this article very informative too.

fda.gov/MedicalDevices/Devi...

Cheers

[casse]

Thank you both, very informative but just scan through so long. Again thank you