Query re. Not testing for ESR as well as CRP

[Pollyanna16]

I have been asked why someone with PMR does not receive ESR results as well as CRP whilst having a flare. This lady has moved to a Cornwall recently and not come across this before. Is it because CRP gives a more reliable result? Would appreciate any thoughts. Thank you.

[PMRpro Ambassador]

There has been a (slow) movement to dispense with ESR as a test for years - it is very non-specific and all sorts of things can go wrong - the test must be done within 4 hours of taking the sample which mustn't be dropped, shaken or exposed to warmth or cold and the test can be a bit fiddly so a result isn't obtained and a resample demanded. Many places are changing over to plasma viscosity which is claimed to be much more reliable - trouble is, they don't have the baseline of knowledge for its meaning within PMR. If you read the rubrics for PMR they say CRP and ESR are both raised in most cases, some say CRP is ALWAYS raised. Neither is 100% true as we know but that is ignored. Neither were raised for me. At one point it was decided that ESR was of value in PMR - and only PMR - but even so, it is really only of value in the context of past readings and labs rarely looked at that. Unfortunately, some labs no longer offer ESR as a test whereas CRP is established as an infection and inflammation marker so is still available.

[Pollyanna16 in reply to PMRpro]

Thank you. As usual a really helpful reply! I’ve been wondering why ESR doesn’t appear in routine blood tests for some time myself.

[Rabbit090 in reply to PMRpro]

My doctor said exactly this! Also that they did do mine but the results don’t get pushed to MyChart.

[pog165g]

Here in Wales they only check for ESR if its specifically asked for by the rhumy

[Louisepenygraig]

I've only ever had raised ESR, never raised CRP

[PMRpro Ambassador in reply to Louisepenygraig]

Not unusual - which is why there was a push to retain ESR for monitoring PMR.

[Sandmason]

In the 2024 article in UptoDate.com they claimed that CRP is more helpful in PMR than ESR. My ESR has always been normal, while my CRP does indicate flares and other inflammation. But some are normal in both and it doesn't disprove PMR.

[PMRpro Ambassador in reply to Sandmason]

Exactly - I don't think that was based on enough data. Neither of mine were ever out of range. CRP never budged, ESR ran high for me.