Does any know what a normal RF blood result is? - NRAS

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Does any know what a normal RF blood result is?


Nurse told me today that my RF result was very high at 1200, does anyone know what the normal range should be?

And I'm sure I read somewhere that a high results may mean an aggresive form of RA....

Thanks for any info :)

14 Replies

Hey Wiliby

I have this page bookmarked

it says 14 to 60units or below is 'normal'

I did read elsewhere though that the RF goes up and down often and a higher than normal reading can manifest also if you are unwell (non RA related unwellness like a virus or something, I'll post it if I can find it)



Thanks for that, had a look at it; surely mine was 120 and not 1200! but she even wrote in on my yellow card.....

I did find a site that mentioned over 300 would mean severe RA and went into meltdown thinking what on earth would 1200 do to me!!!

Feeling a bit silly now :)

Cheers x


Hi Wiliby

Rheumatoid factor is an immunoglobulin (antibody) which is able to bind to other antibodies. Labs have two ways of expressing their Rheumatoid Factor results. A figure on its own, without knowing its significance, can be misleading.

It can either be expressed in IU (international Units)/ML or as a titre. The latter measures how much the blood sample can be diluted before the RF can no longer be detected. A titer of 1 to 20 (1:20) means that RF can be detected when 1 part of the blood sample is diluted by up to 20 parts of a salt solution (saline). A larger second number means there is more RF in the blood. Therefore, a titre of 1:80 shows more RF in the blood than a titre of 1:20.

I imagine, and it is only a guess on my part, that the colon has been missed and your result is 1:200. If this is the case it is quite high and I would assume your RA was quite active when the test was done. The highest I have come across is about 1:400.

A very high reading can be due to the presence of a viral infection.

I'll try and check this out when I visit the hospital this afternoon!

Have you had the anti-ccp test done? It's far more reliable than the RF which isn't highly regarded these days. The RF can give a positive result without the presence of RA as it covers various other inflammatory conditions. When I was diagnosed I had a negative RF and was seriously ill for several years!

Lyn x


Thanks Lynn,

Yes, I would say active as I was experiencing my first flare.

First my husband came down with swine flu, then Amy (5 weeks old) became very ill with it and we were in hospital isolation for a few days, maybe I was also fighting off swine flu myself which was a viral infection.

The stress that we went through may have contributed.

The morning we got out of hospital I started what I understand now was the start of my first flare. Throughout my pregnancy, my doctor thought all RA symptoms were down to hormones so stupidly I stopped breast feeding 2 days later thinking I would return to normal! then it really hit me and was then given the RA test.

Do you think I should ask for a re-test to see if there is a difference?

All makes more sense to me now, thank-you. Very kind of you to attempt to find out at the hospital this afternoon, hope that goes well for you.

Angela x


Gosh, Angela what a time you have had! It must have been very distressing for you all with little Amy.

I have found out some interesting information from our rheumatology nurse practitioner this afternoon. Asking questions (of the right people!) can be beneficial at times :)

It seems a Rheumatoid Factor of 1200 units is possible in some people and is suggestive of a very high level of antibodies in the body. I have only ever come across anything up to about 400! Don't go into panic mode yet though! Although the high number correlates with a severe and aggressive form of RA it can be well controlled. I see you are in Scotland where they use the step down method of combination therapy. You are given 3 DMARDS at the outset and as symptoms lessen the drugs are slowly reduced to a level at which the RA is controlled. In England and Wales we use the step up method and generally start off with one control drug (often mtx) and add to this as required. Each method has its pros and cons.

I imagine your doctors will re-check the RF, every now and again, as a matter of course to ensure the level is dropping and the meds are working well. Be re-assured though, I have a friend in Scotland who was quite ill at the outset and was put on the same meds as you. She now leads a normal life with little evidence of RA and no joint damage. She's now just on MTX and Hydroxy and doing very well :)

You seem to be in very good hands and receiving excellent care. Hope the improvement in symptoms is fast and lasting Angela :)

Lyn x

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Thanks again Lyn,

I juct checked my result again, 1210 oh gosh just when I thought I was starting to get my head round it all!!

Yes, I have a lot of faith in my consultant but a reading that high, I wonder if it is harder to control at that level. I read your blog and what with you being sero-neg for so long but having such a battle with RA it just doesn't make sense whereas I have a very high reading and I actually don't feel so bad at the moment.....

Being on comb therapy hasn't ben so bad as I first imagined and after what I've been reading I think I'd prefer this aggresive approach. It has been suggested that I start on a biologic soon.

Amy is amazing and recovered quickly thankfully, she's been a blessing throughout all of this, I may have been quite depressed coming to terms with it all;but she smiles all day sleeps all night, how lucky I feel to have her!! :)

I may post that question now, see what others RF count is....

Thanks again Lyn, I really appreciate your help xx


Hi Angela

The high level of antibodies is only suggestive of the 'possible' severity of the disease based on the premise that the more antibodies you have the more aggressive it 'may' be. RA doesn't follow a pattern and it's difficult to predict outcomes.

Some people are positive to Rheumatoid Factor but never develop RA, others are are negative yet have severe RA. Please bear in mind the RF is nothing more than an indicator. If the medication that is right for you is found, the disease should be brought under control very quickly so I wouldn't be too concerned just yet.

Although I was only anti-ccp tested a few months ago for the first time (the test wasn't available when I was diagnosed) it seems likely that I have actually been sero-positive most of the way through! My own case highlights the inadequacies of relying on the RF test which, since the introduction of anti-ccp, has largely gone by the wayside because of its unreliability.

It's great that you don't feel too bad at the moment. Keep with the positives and you will be well placed to accept and deal with what RA throws your way. Okay, we perhaps can't beat it hands down but we can achieve a balance that allows us to lead a normal life, one that may require a few changes and adaptations in some respects, but nonetheless fulfilling and worthwhile.

Amy sounds absolutely adorable, enjoy her now whilst she is still your little baby ... they grow up far too fast!

Lyn xx


surely you should have been vaccinated.?. I received the vaccination for swine flu. at gp hurt like hell more than standard flu vaccine. was bothered about it cos.. had seem some one develop epstein barr from it.. but was told had to have it cos of methotrexate plus working in hospital v high risk.. we had an out break last year.. one girl made national headlines.. now dead..put into induced coma.. baby delivered by caesar section v sad


Wasn't offered the vaccination, not sure why now, my husband also declined it then caught it after dealing with a patient (he's a paramedic) so we blame him!! :)

I remember that one being in the news, very sad. Whats epstein barr?

I suppose having RA we have to have these vaccinations now, do we?


epstein barr rare nasty partial nerve damage/ paralyis didnt want the jab cos of the risk.. x


The year before last, myself and my whole family were called for swine flu jab, I had to have 2! Not a mention this year! Have to laugh, does anyone know really whats going on with these vaccinations - my arm was killer too!!!


I was only told initially that mine was positive and they wanted to do further tests for lupus etc. Has never been mentioned since by my Rheumatologists. I don't know if this is something they really look at after the first positive result. as I mentioned before, I had my RF tested in my 30s and it was negative, but lo & behold positive in 40s darnation!!! triggered by stress!!


just to clarify.. i did have the swine flu..jabs.. wiorst arm pain ever! and the normal flu jabs.. the anti body. rf values interesting..

lynns and other blogs in ever day speak.. ra is causes by over active immune system.. body gets confused and then "attacks" its self hence pain, inflammation joint damage.. basically immune sytem too active so would have high anti body levell.. these are the search and destroy things in blood. also so are white blood cells they engulf germs/.viruses .. the vacinations are necessary because methotrexate, ciclosporin. ant tnf.. work to suppress the immune system.. trying to prevent joint damage are you all with me?.. therefore more at risk of nasties such as swine flu, tb, chicken box....

bet before ra was diagnosed most of you hardly got a cold and indeed hardly do now!! I know i dont!!


That makes sense, I couldn't understand at that time why I never caught it after nursing them both.

Haven't had a proper cold in years!!!


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