Blood tests

[JanetRosslyn]

Just wondering... I take my coated Pred at 7am. If I have blood tests at 8am (when it has not yet taken effect) will I get different ESR/ CRP results than if I have the tests taken at 3pm?

AND... sorry, second question... when the results of my last blood tests come through are they likely to be skewed by the fact that I came down with a bad chest infection a few hours after they were taken?

My rheumy is happy for me to amend my dose of pred depending on how I feel and blood results. Not feeling great, but that's more the chest infection than the PMR I think. Definitely not dropping pred till I feel much better, but, like I say, I was wondering if things might affect blood results.

[Hidden]

An interesting question JanetRosslyn. I don't know the answer, but I will be watching with interest for answers

[SheffieldJane]

My guess is that your blood test results will show a lower level of inflammation because you are on a course of Prednisalone ( which doesn’t cure, but relieves the inflammation). I also think that any kind of infection gives you a false high or rather it will show up. So they won’t give an accurate picture of PMR - only your symptoms do that.

[JanetRosslyn in reply to SheffieldJane]

Thanks Sheffieldjane. I know pred works by reducing inflammation, but just wantwondered if the levels of inflammation in the blood varied throughout the day? Have decided that from this point forward I will always have blood tests taken at the same time of day so I can get a true comparison each month, but the question still niggles at me... especially early on the morning when I'm lying awake in bed and my mind goes a wandering.

[Marilyn1959]

I too am interested in answer to timing of pills influencing results. Thank you for thinking of this and posing the question.

I know my Rheumy tells me not to have blood test if I suspect an infection of any kind. Presumably because this might skew results?

[JanetRosslyn in reply to Marilyn1959]

Good morning Marilyn1959. Yes, with the timing thing, I don't know why I hadn't even thought of it before (I've been on Pred since Dec 2016) but now I have thought about it I can't help wondering.

And it sounds as if the chest infection I had brewing is likely to affect my latest results. I felt a little 'off' when I had the bloods taken, but it wasn't until a few hours later that I started feeling really rough and the coughing started. Oh well, when the results finally come through (10 days) I'll be wary to interpret them cautiously!

Thank you.

[PMRpro Ambassador]

If you keep a record of the ESR/CRP results it shouldn't make that much difference what time the blood test is taken - it is an overall trend you should be looking at and it should be generally falling/staying low whichever stage you are at. Some of the protein level reflects the previous days, the protein level won't fall and rise quickly with the dose of pred, that just wipes up the inflammation itself. You should never up the pred just because you had a single raised blood result - you should repeat it a week later and see if there is a trend. The ESR and CRP only reflect the amount of inflammation somewhere - they aren't the inflammation itself.

If you were hatching a chest infection then both ESR and CRP may have been raised because of that - it is impossible to tell without knowing how much inflammation was already present.

TEN DAYS to get the blood test results? That's a trifle useless! You need to know what they are now, not 2 weeks ago!!! I know the system is different - but I can collect mine from the lab the same day.

[JanetRosslyn in reply to PMRpro]

Thanks PMRPro, that's useful info. And yes, 10 days to get results, if I'm lucky! They tell me it's 7 days, but that never happens and every time I have to press the doctor to chase them for me. And now they've just started adding another delay because the staff won't let me have the results without the doctor's specific authority... every single time... Last time, they told me they had the results at day 10, but then i had to wait another 4 days before the doctor gave his authority to release them to me (weekend and his non working days). Madness. I'm writing to the practice manager.

[PMRpro Ambassador in reply to JanetRosslyn]

Yes - sounds reasonable and something I;d be doing. There REALLY isn't a lot of point waiting for 2 weeks to know - if you are flaring it could have run away with itself by then!

[piglette]

My CRP and ESR rocket up if I have a cold.

[JanetRosslyn in reply to piglette]

Useful to know, Piglette. It will be interesting to see what's happening to mine... eventually. Thanks.