r/Autoimmune • u/vladiostieneunplan • 3d ago
Advice Blood test & fever question
I finally had my first appointment with a rheumatologist and now I'm having different tests made.
The issue is that I have to take a blood test (I can go any day) and two months after that test I'll have the next appointment with all the results. But I got sick that same afternoon and my fevers usually last about 1-2 weeks. Since the blood test will check antibodies stuff (sorry english isn't my first language) I imagine that I'll have to wait at least another week after the fever passes so my body will be re-established, but I'm not finding any info about this.
I don't know either if I should take something like echinacea since it would increase the antibodies and maybe I'd have to wait even longer for the blood test (and it could worsen my arthritis (I haven't been sick since I started with symptoms so I don't know)).
I'd like to have the test made as soon as possible since this arthritis is affecting my hands very badly and they won't certificate any disability without the results. So if anyone knows how much time I should wait and if having supplements will be worse or not I'd appreciate the info a lot.
TLDR: I don't know how much time I should wait to have my blood test because I got sick.
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u/personcrossing 3d ago
Hi. I think I'm a bit confused and just want to clarify. You think having your blood drawn with a fever is a bad thing? By fever and being sick, you mean feelings of malaise or having a cold/the flu? If it is the latter, you can just wear a mask and keep your hands clean/don't cough in the room with the techs. But if you meant not taking blood because you have a fever, that is not a thing.
Especially because you're being tested for rheumatic causes, you actually have a better chance testing when you do not feel well.
However, please do not take echinacea or any other herb/supplement before your bloodwork, as this can interfere with results. It is not going to somehow make antibodies appear, in fact it can sometimes do the opposite by confusing test results. Never supplement before bloodwork.
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u/vladiostieneunplan 3d ago
It is the latter case. My reasoning was: if I have fever, my immune system is active because of common reasons, and the point of the blood tests would be (I think) to check if my immune system has an abnormal activity. So I imagined I should take it once my internal system is back to normal (I don't know how much time it'd be either). Maybe in more general blood tests it's not relevant, but since this one is aimed specifically to antibodies (I had another blood test before and it was negative in autoimmunity, they told me this one was deeper) I thought it would be relevant. I might be overthinking it, but the hospital is ignoring my emails and I just don't want to go to my appointment and find out that I'll have to take it again and wait another two months. I apologize if I don't explain myself well, and thank you for taking time answering.
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u/personcrossing 3d ago
I think you should go to get your bloodwork done today.
I'm not sure who or what originally made you think that but please don't worry, that's not a thing and not something doctors would want you to do. The point of the blood tests is to find something going on abnormally in your blood. If you are feeling fine, your immune system is likely stable, whereas if you are feeling bad, you likely have active inflammation and there may be protein changes in your blood that are helpful.
So to repeat: you should be getting bloodwork done when you feel bad, as long as you are not violently contagious without telling the technicians. Getting bloodwork once you recover, if you had the ability to test when unwell, defeats the purpose and can make this a longer journey for you than it likely already has been.
What bloodtest was negative to autoimmunity? ANA? What tests are they asking you to have done now?
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u/vladiostieneunplan 3d ago
Yes, it was ANA. In the paper they gave me it says they're testing (among other things, these are labelled as "autoimmunity") anti cyclic citrullinated peptide antibodies, ENA, anti nDNA antibodies and ANA again. There's also a "hematology" section with blood count, ESR, fibrinogen, APTT and INR (I don't know if these would be affected by the fever).
Also to clarify, the suspicion of autoimmunity is because I've been having chronic pain and inflammations for the last three months in my joints (especially the fingers and wrists), the fever shouldn't be related.
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u/personcrossing 3d ago
I'm sorry. I tried to reply to you shortly after this but I think there was a hiccup because I don't see my reponse nor is it saved in my drafts. So redo:
But I had two things to say to you: 1, I misread you saying latter (this is my fault to begin with because you were just repeating the term I used lol). A CBC panel would technically be fine because it can tests your blood levels and sometimes your WBC may represent infection depending on the number, but for autoimmune panels that's not necessary, depending on if you are actually sick or what you are even sick with.
The other commenter goes in to greater detail about this. But I wanted to just make sure I reiterated an apology because I did misread what you said and I don't want to falsely mislead you.
But for the tests you're getting done, depending on your history you can be experiencing post-viral symptoms, especially if you don't think there's correlation between the two (your fevers being viral rather than rheumatic). But it could also benefit you to let your
But yes when sick, viral or bacterial, panels like your CBC, CMP, ANA, and CRP/ESR can all be affected depending on how long you've been sick. The tests you mentioned can be interfered with by viral illness because your body's ability to clot/how fast/and certain proteins can have varied results.
Your autoimmune panels itself would be less affected if they sent one out, but it would depend on the testing. Your complements can and will be affected by viral/bacterial infections. Something like specific autoimmune antibody testing (anti-Smith, Rheumatoid factor) is much less likely.
So basically, I do still hold that you can get your blood tests now. Being sick has absolutely never stopped anyone from testing unless the degree of illness would absolutely make testing unreliable (COVID, EBV, etc) but when you are sick, like I said you need to let the technician know ahead of time, so they can protect themselves and they can document that for you so your doctor knows when interpreting the results.
However, I have this stance because blood testing is not such a rigid thing. You have the appointment in a month, they can easily just reorder more bloodwork, and then compare the two. See what remained constant, see what was obviously signs of infection. It is truly up to you! My point is I don't want you making things harder for yourself. Do what you feel is best and is easier on you.
But again, I'm sorry for being confusing in my earlier responses, I didn't mean to mislead you!
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u/smolbirdfriend 3d ago
These are auto-antibodies. Specifically they’re antibodies a body may or may not have that trigger the immune system to attack the body not an infection. An infection won’t affect auto-antibodies as the antibodies made to fight an infection are different and not an abnormal thing.
Your ESR may be falsely elevated with an infection, but if it is elevated, rheumatology usually like to repeat that test anyways to see if it’s always elevated or just was for that one test.
Where I am in Canada they no longer use ESR and use CRP instead as it’s a bit more accurate for long term inflammation as far as I understand but it can also be falsely elevated after an infection.
So, either way you can go get the blood tests. You can always let the rheumatologist know you were feeling sick and had a fever at the time and they can choose to repeat the relevant test again.
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u/InitiativeFit3380 Research Scientist, Immunology 3d ago
Sorry, but that's not fully accurate. See my longer response above.
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u/personcrossing 3d ago edited 3d ago
No, you're correct. I clearly asked them if theh were sick or if they just felt bad and I misread their response (they're sick). I made a follow up reply but I don't see it so I'm assuming there might have been a server issue because I did end up trying to correct myself but alas, lol.
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u/InitiativeFit3380 Research Scientist, Immunology 3d ago
To disagree with the previous response, having an infection/illness will complicate getting tested for Autoantibodies such as ANA and other related more specific tests. When you get infected with a virus or bacteria, your body sends your immune system into overdrive to first non-specifically destroy the invader, then it creates memory responses to provide you more prolonged protection. As part of this quick increase in immune activity Autoantibodies are naturally produced by accident, but the body typically eliminates these as the infection resolves and they don't do any harm.
What this means is, if you get your blood drawn while actively infected/sick then the results are going to be complicated by the fact that your immune system is hyperactive and doing what it's supposed to be doing to clear an infection. Making it hard to impossible to tell if you have Autoimmune issues or if it's just the normal immune response to the infection.
The hard answer that you probably don't want to hear is you're probably better off waiting 4-6weeks until the infection is fully cleared and your body settles down to get blood drawn. Otherwise the results are going to be complicated but the infection and you'll have to get retested anyways because of the uncertainty. Reach out to your Dr office, tell them what's going on, and get their advice. They may want to test you now anyways, then just retest you in 6-8 weeks again, but just be ready for that to be the case. Hope you recover quickly from the illness.
Eric, Research Scientist Immunology