Rheumatoid Arthritis Test: Some Funny Factors

Oh finally, the real “RA test”!

The other day, I picked up my lab test results. Because of new insurance, I’d been sent to a new lab. New procedures. New forms. New nightmare parking lot.

I’m such an RA geek I start reading my blood test results the minute they are handed to me while walking out the door. This time something jumped off the page at me. New name for the Rheumatoid factor: it’s the RA Test.

Oh good, they finally found the definitive test. Oh darn, I passed.  Oh no, that’s nuts.

Is there a Rheumatoid Arthritis test or not?


Oh you wanna know more? About a year ago, I wrote my first posts about Rheumatoid Arthritis blood tests. In Is There a Blood Test for Rheumatoid Arthritis? Part 1, I tried to explain in plain talk how four different tests are used together to help identify Rheumatoid Arthritis. Then, in Blood Tests for Rheumatoid Arthritis, part 2, I looked at the reason all the blood tests we do for Rheumatoid Arthritis still do not provide an adequate Rheumatoid Arthritis test. One third to almost half of RA patients have negative results on the commonly used tests for Rheumatoid Arthritis.

Those are nice short posts with easy to understand language. But I did hours and hours of research. There are lots of scholarly articles linked there. I hope you’ll look at them when you have time.

“False negative” Rheumatoid Arthritis test

It’s not “false negative.” It oughta be called “fake negative.” What they do call it is sero-negative. It means we didn’t find the Rheumatoid factor antibodies in your blood serum. At least the ones we looked for. At least today.

In another post, Rheumatoid Factor Test: Should We Rely on Rheumatoid Factor Levels, we learned that there is actually more than one kind of antibody to be tested and more than one kind of Rheumatoid factor test. A negative result on a Rheumatoid factor test could be positive if it were performed in a different way. There is not a Rheumatoid Arthritis test. Period.

I was wondering why it was so hard for many people to understand that Rheumatoid factor is NOT the “Rheumatoid Arthritis TEST.” Now I get it. What else were the poor dear patients to think when they look at the paper and it says “RA Test”?

Docs who say it, however, have no excuse for being confused since they went to school to learn this stuff.

“False positive” Rheumatoid Arthritis test?

This is also a misnomer. There is no “false positive” because there is nothing “positive” or definite about a Rheumatoid factor test. Patients with RA may have Rheumatoid factor antibodies that are detectable at some times and not at others.

But there are many of other things that can trigger a positive result to a Rheumatoid factor test. Here’s an article with a fairly long list of triggers for a positive result to the so-called Rheumatoid Arthritis test on AnswerBag.com. Some triggers for a positive test include autoimmune diseases, infections and viruses, cancers, kidney disease, HIV, and other chronic diseases. I wonder what those patients think when they sit in their car reading RA Test: positive.

Recommended reading:

Kelly Young

Kelly Young is an advocate providing ways for patients to be better informed and have a greater voice in their healthcare. She is the president of the Rheumatoid Patient Foundation. Kelly received national acknowledgement with the 2011 WebMD Health Hero award. Through her writing, speaking, and use of social media, she is building a more accurate awareness of Rheumatoid disease aka Rheumatoid Arthritis (RA) geared toward the public and medical community; creating ways to empower patients to advocate for improved diagnosis and treatment; and bringing recognition and visibility to the Rheumatoid patient journey. In 2009, Kelly created Rheumatoid Arthritis Warrior, a comprehensive website about RA of about 950 pages and writes periodically for other newsletters and websites. Kelly served on the Mayo Clinic Center for Social Media Advisory Board. There are over 42,000 connections of her highly interactive Facebook Fan page. She created the hashtag: #rheum. Kelly is the mother of five, a home-schooler, Bible teacher, NASA enthusiast, and NFL fan. You can also connect with Kelly by on Twitter or YouTube, or LinkedIn. She has lived over nine years with unrelenting Rheumatoid disease. See also http://www.rawarrior.com/kelly-young-press/

15 thoughts on “Rheumatoid Arthritis Test: Some Funny Factors

  • July 13, 2010 at 12:37 pm

    When I was diagnosed with rheumatoid arthritis I did receive any “positive” RF, which I have also heard referred to as a RA factor. But it was not until about two years later when the nodules started appearing up and down my arms and I had other symptoms that all the doctors went, “oh good, we diagnosed her correctly.”

    I felt like you did; I was relieved I had a correct diagnosis, but unfortunately additional symptoms were needed to be able to confirm that.

    There is a reason it’s called the “practice of medicine.”

  • July 13, 2010 at 3:30 pm

    Kelly, I appreciate so many things you do but your attention to this topic brings my greatest gratitude. Periodically over a 12 year span of time doctors would look at me and say this seems like RA. Then the sed rate would come back elevated and they would be even more convinced but as soon as that rf factor came back negative they would decide they were wrong and give me nsaids and a pat on the back. I finally have a great rheumatologist and feel as good as I have felt in a very long time because of treatment. I know there are others out there like me and I would love to have had the information you share here 12 years earlier. I am certain you are helping many with this research. Thanks and keep up your good work.

    • July 13, 2010 at 6:00 pm

      Thank you for the good words Kay. 😀
      It bothers me that some doctors seem to foster a view that there are two types of RA: sero-positive and sero-neg. There are actually several antibodies that can be identified and perhaps one day we will know several classes of RA. As far as the Rf goes, many patients like you will one day see a positive result. I’ve seen those who have a Rf result that is sometimes negative and sometimes positive – that’s not very black and white if you ask me.

  • July 13, 2010 at 9:23 pm

    I didn’t have time to read all the information, but there is a test call anti-CCP (anti-cyclic cintrullinated peptide antibody). That, when RA is suspected, is a much more precise marker than the RF.

  • October 4, 2010 at 7:29 pm

    I guess my excitement at hearing a diagnosis of RA from my Doctors should be tempered, with all the false positives in the testing of it, although my feelings and description on how the pain was attacking me sure matched the symptoms given, time will tell…

  • May 23, 2011 at 10:17 pm

    I understand how if one is testing negative, this kind of information might provide some reassurance. But what about those of us who test off the charts for RA factor? Mine is holding steady at 550. Sed rate 48, CRP 1.5. My symptoms were as follows: joint pain, swelling, stiffness and redness at several joints (some symmetrical, others staggered); low grade fevers (below 100F) almost daily; extreme fatigue; extreme pain in hands/wrists/fingers and feet/ankles/toes—to the point that I couldn’t use them, sleep, or do anything else. I thought I’d been screened for all other possible diseases (eg: Hepatitis ABC, TB, Cancer, etc) but after reading this, I’m a little freaked out. One of the things the Rheumy told me was that RA diagnosis can sometimes be determined by how well a patient responds to Prednisone—and I did respond within about a month. But a month after that I was flaring again, and it’s been back and forth for six months now. Is there something else I should be asking to be tested for? What am I missing?

  • August 26, 2011 at 4:01 pm

    Hi Kelley

    Your webpages have been so helpful. I contacted you recently and you replied. If I hadn’t kept reading the information you had given I would have continued to be told I have fibro. I remained persistent. I had a new Dr and this is how It started along the lines of having RA. She did some research and made some phonecalls more that The RA Dr did.
    It turns out that as I have hepatitis C a small percent of people are developing what they call hepatitis C arthritis which mimics RA without the swelling. Have you heard or know anything about this please.

    • September 2, 2011 at 11:20 pm

      I do not know about it – but I have heard it from one other patient – who is now doing well. I hope they sort your yours very soon!

  • October 17, 2011 at 12:21 pm

    I am happy to finally find such in-depth information about RA. The doctors swore I had it but when both factor tests came back neg they moved on. I tested positive for sjogrens disease and see a rheumatologist on thursday. I have read it is a secondary disease to RA and hope they do more testing on me.

    • October 18, 2011 at 10:32 am

      Tomi, Good luck on Thursday! I hope that you have a good rheumatologist who will yes run more tests, but also take a thorough history and do a good examination! There is so much more to RA diagnosis than the Rf test. About 1/3 of RA patients are Rf negative. You can read more about diagnosis of RA using the tab on the menu at the top of the page where it says “Do I have RA?” and all the posts about diagnosis are also found using the tag “RA diagnosis” – here’s the link: http://www.rawarrior.com/tag/rheumatoid-arthritis-diagnosis/

  • December 9, 2014 at 12:03 pm

    Does Orencia affect the RA factor? CAN it give a false negative? Im so confused about all this crap. Does Orencia help fibromyalgia?

  • April 9, 2015 at 8:59 am

    2 years ago, I had an elevated RA factor so my NP sent me to Rheumatologist. He examined me, even did a breast exam on the first visit. He would xray my feet or hands every month, but always insisted that I undress completely.(He meant naked, which I never did? After about 4 months of xrays, no other labs, and no other exams other than holding my hands, he asked me if anything was hurting. I told him my knees, but they always hurt. He told me to undress so he could check them, but I had a surprise for him. I had gym short under my sweat pants. He then told me to take those off too, which I refused. I told him that he could see my knees perfectly without me undressing any further. He glanced at my knees, told me that I had OA and fibromyalgia, that I don’t have RA and told me to follow up with my NP. The report he sent to her was like there is nothing at all going on. I have swollen joints, low grade temps off and on, the fatigue makes me want to cry, and every morning it is like my feet and ankles were placed in a vise while I slept. I am only 48 yrs old, and used to be in great shape, but my muscles are wasting and I feel like I am 90. Some days are worse than others and this is a bad one. I don’t know what to do. I don’t want people to think I am a complainer, so I don’t say anything but now my thumb tips and a few fingers are starting to curve. I just don’t know what to do or how to tell a good dr from a not so good one. Everyone that I asked about the other RA dr said he was great, but they were men. Any advice would be appreciated.

  • September 28, 2017 at 8:33 am

    Hi there! So glad I came across your page!
    So I have a 5 year old who I believe may have juvenile rheumatoid arthritis, but all blood work comes back fine. I am not really sure where to go at this point and am trying to do my research. My dad had it as a kid and my husband nephew who is 9 now has it. My little guy is in pain just in his knees all the time. We are constantly giving him ibuprofen to no avail and I see it starting to slow him down. My heart aches for him and I wondered if you had any suggestions on what are next step should be! Thanks for your time!

    • October 15, 2017 at 11:01 am

      Dear Jordyn, My heart goes out to your son. Please tell him there are a lot of warriors who hope he feels better. My suggestion is to start looking for a pediatric rheumatologist that has good reviews – this might take a while, but you need one whose patients trust her/him. Meanwhile you should watch carefully for any swelling or puffiness & photograph it. Re- test the blood work as often as the ped says – probably at least 1 x per year. Test all these antibodies: ACPA (anti-CCP) 14-3-3eta, rheumatoid factor. If there is swelling or persistent pain, you can try to get a musculoskeletal ultrasound – but they are mainly only in academic centers in the U.S. A couple of my kids have shown signs too, so I know how this is heartbreaking.


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