Rheumatoid Factor in PsA

Hi everyone. I’m being screened for a Clinical Trial specifically for PsA, which was my diagnosis six months ago. A month ago, as part of the screening process, my bloods showed zero rheumatoid factor (but there was rheumatoid factor originally). This started me off as an acceptable candidate. Now the second screening tests show my rheumatoid factor level is up to 34 after being off all medication for five weeks (I’m in agony!) There is now the question that I may have RA as well as PsA, therefore not eligible for this particular trial. I’m gutted! My Consultant now has to talk to the drug company to see if I can be accepted. If not, I may just have to go back to Methotrexate and pray I can get onto a biologic soon. Has anyone else any experience of having both PsA and RA? :sleepy:

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I had a chat with my daughter’s rheumatologist. My daughter has elevated anti ccp among other things, but is negative for rheumatoid factor. She was saying that anti ccp is actually more indicative of ra than rf. Regardless, both can be raised and it does not mean that you have RA. It can be elevated with other conditions too, including Sjogren’s. Take a look at this on Rheumatoid factor

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Though I haven’t had the experience myself, my understanding is that RF is just an autoantibody - it is positive in around 80% of patients with RA (though I remember reading years ago that it’s positive in only around 50% of patients within 3 months of onset), but can also be positive in Sjogrens, lupus, and a few others.

Whilst I haven’t looked into it with any depth at all, it kind of stands to reason that if it can be positive in sjogrens, there may be PsA patients with positive too (oh, and it can also be positive in people without arthritis, particularly if they have a family member with RA).

So, unless there is some other compelling indication you have RA, I wouldn’t let one positive RF result worry you in terms of having both RA and PsA.

I can really understand your worry about that excluding you from the trial though! (Must admit I’ve always had too many other comorbid possibles to even bother trying). On a more positive note though, if your Rheumy is willing for you to do a trial, then surely you are a biologic candidate if trial eligibility falls through. I can’t imagine, as a medical professional, recommending someone for a trial of untested drugs, then saying “oh but you’re not bad enough to need biologics, ho ho ho”


We certainly have had members here with both PsA and RA but I’ve not been able to find any past discussions so far by using the search option.

A bit of googling tells me that 34 is high enough to indicate RA. (Though a bit of googling shouldn’t be relied upon).

You’d think that the suspicion that you may have both diseases might bump up your chances of starting a biologic soon.

I think Jen most definitely has a point! And I think you should use that to your advantage. ‘Surely I must need biologics doctor, or you wouldn’t have put me forward, would you? I mean, I’m certain you’d never use your patients as guinea pigs …’ (Okay, scrap the last sentence).


Thank you both for your replies. I read a while ago that PsA patients don’t
have RF in their blood, however my Consultant disagrees with that. He says
it’s possible. This isn’t the first positive RF result I’ve had though.
Strange that it was positive at the beginning, negative a month ago and now
is back to being positive. What weird diseases these are.

Thanks for the link Stoney - I see it doesn’t mention PsA either, but the
fact that RF being positive doesn’t necessarily indicate RA is reassuring.
I was originally diagnosed with RA then the diagnosis was changed after
further testing, scans and X-rays to PsA. I now believe I have both. I have
a family history of psoriasis and have had the odd tiny patch myself many
years ago but have never had the typical plaque psoriasis that my sister

I’m still waiting to hear back from my Consultant as to whether or not the
drug company will accept me for the trial, as it is specific to PsA. If
there’s any chance I may have RA too then I’m out, as their results won’t
be accurate.

Jen75 they aren’t untested drugs on the trial - it’s a comparison trial
between two biologics to see which works best for PsA. Humira and Cosentyx
which are both tested and approved. So I don’t yet qualify for biologics as
far as the NHS are concerned, however if I don’t get on the trial I think
my Consultant will still push to get me on a biologic asap as my disease is
very active. I had to have three affected joints, swollen and tender, to
get on the trial and I’ve got 42! :confounded:

Thanks Sybil, if you’ve read my other reply to Stoney and Jen you’ll see that my rheumatoid factor fluctuated. And the Research Nurse seems to think it’s likely that I have both RA and PsA based on all test results. Oh no!!! :scream:

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Gee, Katie, what a disappointment—for two reasons, 1-possibly having both PsA and RA (that doubly sucks) and 2-being eliminated from the trial if that’s the case!

I know you were so looking forward to the trial—and for quite some time now. Now being off the meds and getting turned down is so hard to swallow!

I hope your rheumy agrees you’re ready for a biologic and this turns out to be a good disappointment…?..if there is such a thing!

I hope you’re able to keep working on your art—I know that’s not easy when you’re in pain. Take care, and hugs to you!

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Ahh thanks Grandma_J

Yes it’s a double blow, but as you say perhaps it’s meant to be and I get
to go on a biologic anyway. Fingers crossed :crossed_fingers: as I can’t face Methotrexate
again I don’t think xxx

Yet you have more than enough swollen joints, and have indeed tried 2 DMARDs. I think not being able to tolerate Sulfasalazine counts as having tried it, according to the NICE guidelines.


Oh really, that’s great. Hope yet! Thank you xx

I have seen this in the NICE guidelines, though perhaps they don’t want patients being too wised up, they only seem to mention qualifying for biologics when DMARDs haven’t worked these days. But it depends how ‘haven’t worked’ is interpreted. https://www.psoriasis-association.org.uk/media/PsA_Second_Line.pdf interprets NICE guidance like this:
‘Biologic Therapies should be considered if: -
The person has arthritis with three or more tender joints and three or more swollen joints, and at least two other DMARDs, given on their own or together, haven’t worked or cannot be tolerated (ie. caused significant side effects that meant treatment had to be stopped).’

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Sybil you’re so helpful. Knowing my Consultant he’ll go down that route for
me I’m sure. Thank you so much :blush:

I started off RF negative and then turned positive. I actually don’t know where it’s at presently. Bath noted it but is of the view I only have PsA presently and certainly that’s good enough for me. I must remember to explore it again though at my next appointment in March. However I’m doing pretty well on sulfasalazine at the moment so my view is long may that last. I so hope @Katie909 you get back on something soon and just feel lots better.

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Thank you @Poo_therapy. I was always RF positive from the beginning and
then it fluctuated. Five weeks ago I had it tested and it was negative,
zero in fact, which made me eligible for the trial. Last week I tested
positive at 34 and the drug company want 13.5 or less. I was on
Methotrexate and it helped but I had awful side effects, I was about to
start on Sulfasalazine when I realised I couldn’t take it as I’m allergic
to aspirin based products and it’s also an anticoagulant- I’m already on
anticoagulant therapy for a DVT. That’s why my Consultant thought I’d be a
good candidate for this biologics trial. He may persuade the drug company
to include me as all my other tests are fine, but I’ve been told it’s
unlikely so back to square one xxx

I’m sad I simply couldn’t tolerate the mxt side effects. Lasted no more than a couple of weeks either time, first by tablets, then by injection. I hadn’t appreciated sulfasalzine was an anticoagulant. That’s why when I cut my finger or something I bleed just more than usual! My bloods were a little ‘sticky’ initially so obviously it’s now helping that. The lack of side effects on sulfasalazine is for me a godsend though. I truly hope whatever about trials you just get on something soon that helps you.x

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Thank you x. :heart:

You’re right Sybil, I’ve been rejected for the clinical trial but my Consultant has just rung me to say he’s got me onto a biologic through the NHS (Humira) and to go into hospital this afternoon for a steroid injection and to talk to a Specialist Nurse about getting started with Humira. Hopefully I’ll get some relief soon. Thanks for your support. Really appreciate it xxx


That is wonderful news! I really like the sound of your consultant. Knowing that you have a good rheumy AND a biologic definitely in the offing too, you may find you start to feel a little bit better even before treatment commences! That’s so often the case.

Anyway, I just hope you get as good a result from Humira as I have. I did improve a fair bit on Mtx over a 3 year period but my swollen joints, though more supple, never went down. And then, with Humira, they returned to normal size and little by little I started to feel really well in so many ways.

I’m really happy for you :grinning::hugs::tada:

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Wow Sybil, thanks for your response - that’s so encouraging about Humira. I
have to say my Consultant is a star :star2: and has always done his best for me,
I’m so grateful he was appointed to me! I had a meltdown yesterday with
exhaustion and pain but do feel better just knowing I’m getting started
soon on a biologic - and the steroid injection in my bum :confounded: will help too!

Yay for steroids in the bum! I (briefly!) had a rheumy who was a right comedy act - oh my gawd he was dreadful! But he did say just one good thing and that was that if you gave steroids to random people in the street they’d all feel better, regardless of how healthy they actually were. And for us, a great reprieve!