Blood Tests for Rheumatoid Arthritis, part 2
Many people with active RA have “normal” test results
In my last post, I posed the question: Is There a Blood Test for Rheumatoid Arthritis? I told you that the answer is yes – and no. I went on to describe the “yes” by summarizing four principal blood tests used in diagnosing Rheumatoid Arthritis. Now it is time to elaborate upon the “no.”
I found this startling:
You may already know that there is not a blood test to definitively measure Rheumatoid Arthritis. No blood test can be used to precisely diagnose RA in all patients. But just as importantly, there is not a test which can reliably gauge the degree of RA activity within a patient.
But, wait, it gets more interesting:
The most thorough study of the usefulness of these tests was a large study conducted in both Finland and Tennessee. Almost 2,500 patients were studied over a period of 25 years. The CRP, sed rate (ESR), and Rheumatoid factor (Rf) were all monitored.
Look at some of the results. ESR was normal in 45% (Finland) and 47% (Tennessee) of patients. CRP was normal in 44% and 58%. And all Rheumatoid factor (Rf) tests were negative in 38% and 37% of patients.
Why does this matter?
Doctors commonly use these three tests to “monitor disease activity.” That means they are looking to these numbers to show whether the disease is active and whether a patient’s current treatment plan is adequate. Some doctors are more reliant upon them than others. I have met one rheumatologist who says that he relies upon them completely.
So read this carefully:
Many people with RA experience plenty of active and damaging disease while one or all of these indicators are “normal.”
Here are a few cases in point:
- “Sometimes also patients with rheumatoid arthritis have low CRP response in relation to the severity of the disease.” Axis-shield
- “By the same token a normal sed rate is meaningless in a patient with known SLE if they are having symptoms of a flare.” (Sounds like this rheumatologist considers the lab test pretty useless to measure flares in Lupus.) Nathan Wei, MD, FACP, FACR
- “However, a low CRP level does not always mean that there is no inflammation present. Levels of CRP may not be increased in persons with rheumatoid arthritis and lupus. The reason for this is not known.” University of Southern California
- “Many people with active RA have inactive values of ESR/CRP and many with inactive RA have active values.” Journal of Rheum.
- “Both ESR and CRP were normal in 33% and 42% of patients” in the large study mentioned earlier. Journal of Rheum. abstract
What is the bottom line?
Only a small percentage of people with RA actually had abnormal results to all three blood tests (ESR, CRP, and Rf) in the huge Finland / Tennessee study. “All 3 tests were abnormal in only 28% in Jyväskylä (Finland) and 23% in Nashville (Tennessee).” The authors of the study concluded: “Normal ESR, CRP, and RF are seen in a substantial proportion of patients with RA at this time.” Journal of Rheum. abstract
There is hope.
I had already spent many grueling hours researching for this series when I happened upon an article entitled The Many Myths of Erythrocyte Sedimentation Rate and C-Reactive Protein. I was thrilled to find a rheumatologist who holds the following viewpoint. “Learning when to ignore a test and when to rely on it lies at the heart of good medical care… It is, perhaps, time for more research about testing and measurement in clinical practice.” I recommend the article in the Journal of Rheumatology by Frederick Wolfe, M.D.
Recommended reading:
- Is there a blood test for Rheumatoid Arthritis? Part 1
- Dr. Dolittle and Rheumatoid Arthritis
- How Rheumatoid Arthritis Impacts Lives
Greetings and gratitude Kelly, (from downunder)
Researching and based on my own experience there is a great need more for more reliable tests. One year ago at 53 I was diagnosed RA positive. I am still in denial. I Stopped the Methotrexate and prednisone four months ago. As all tests for CRP & ESR normal low range. My rheumy diagnosed possible fibro in response to my pain swelling symptoms stating RA was well controlled. Last few weeks fever, fatigue, swelling, restricted movement in more joints can’t bend thumb or straighten middle fingers and excruciating pain like broken fingers. No redness or heat. More joints affected, wrists, knees and ankles. If anything I am underweight. Also I have had the flu last few weeks. My CRP ESR all normal!!! Hohum. I am going back on the meds although I wish we all could have remission without the toxic medication-as I am scared of permanent damage.
I do not have all of my lab tests results. Due to two past positive RF tests and arthritic pain and inflammation episodes I finally saw a rheumotologist. I saw a hand specialist who diagnosed moderate joint damage at the base of one thumb that a joint replacement would relieve chronic pain and swelling. The rheumy’s opinion on consultation was I had early onset osteo arthritis and no RA. Again I am positive for RF and negative for sarcoidosis and Hepatitis A and C. Of course when I have had symmetrical swelling of all fingers and sometimes 2-3 no MD has seen me. The hand X-Ray showed no ulnar deviation which I have in one hand. Would the technician lining my fingers straight have given a false X-ray impression? Maybe flRes of osteoarthritis also occur symmetrically.
My last flare was both hands with several fingers involved. When the worst ended the one thumb continued to have pain. I conclude I may not know what causes the positive RF tests and I may not be believed I have pain in my hands episodic that makes work difficult and activities of daily living.
I was diagnosed last week and finally decided tonight to seek info from wise and caring RA’ers. I found your safe site but read a link that sent me googling down the rabbit hole that is the internet… I will stick with you from here on out. I am so very grateful you are here. Thank you!
My Rheumatologist has run the Vectra DA twice so far. 1st one came back just in the Highly Active range. ~5 months and after switching to Humira it dropped to the low activity range! If you don’t have insurance the test is very expensive. Luckily for us TRICARE does cover it.
Rhuematologists need to give you advice and instruction on R.A., after giving you a diagnosis !!!!!!! Also I’m afraid to take the Methotrexate. It seems to do as much harm as Good .What do others think of it? What is it’s Purpose????
Hi dianee – Some doctors can’t offer that advice because they don’t know what information is needed. That’s one of the things the Rheumatoid Patient Foundation has done in creating brochures used in doctors’ offices. http://rheum4us.org
On methotrexate – there are many articles on that here on RAW that would help you be informed and decide what’s best for you – and lots of comments to hear other people’s experiences – https://www.rawarrior.com/tag/methotrexate/
I cannot believe what I am reading….
Well, here’s the deal. I’m a 29 year old guy who for 1 month has been having pain in both wrists, fingers, ankles, and stiffness in the fingers when at rest.
As an avid artist and model kit enthusiast, the prospect of having RA is
soul crushing… Like a sick joke.
I already have one autoimmune condition. Alopecia Areata.
So one ruins my looks, and the other might potentially ruin my ability to do
the thing that I love.
I had all of the blood tests done and everything came back normal.
I rushed to my GP within a month of these symptoms knowing that early treatment is
very important.
He is saying that I don’t have it because of the blood test results.
Maybe it’s too soon for it to show on a blood test, or maybe i’m seronegative?
I don’t know…
Meanwhile, the pain in my fingers seems to be worsening.
Could this be ANYTHING other than RA??
I’m not sure what to do next..
The GP can’t say you don’t have it because it’s supposed to be diagnosed by specialists – rheumatologists or sometimes immunologists. (Not that they don’t miss many diagnoses too.) All that to say – you need to see a specialist.
If labs are still negative, it can still be diagnosed obviously and yes, levels increase over time as you said. In Europe, they’d use ultrasound to identify inflammation or increased blood flow. In the US, you have to get one who can recognize what they see and what you tell them.
Could it be anything else? There are a few rarer conditions that cause similar symptoms but RD is the most common. And blood tests can rule out rare syndromes. Barring that, it could be rarer rheumatological disesae – and being male, maybe a spondylarthropathy. But starting in hands and widespread other joints makes that less likely.
My best advice, if you have any swelling or redness or anything that can be seen, schedule the doctor appointment then. Take pix if you can’t. Repeat the lab tests at a different lab next time since errors happen. Mention any family history of RA/ RD or anything else that might help identify it.
RD can be “invisible” for a long time – but like you know – waiting means a lower chance of treatment response. So many of us are fully disabled because of this barrier. However, better doctors can “see” what others can’t – such as tenosynovitis (seen on the palm side of the hand), so find a doctor who will listen.
Best of luck to you David.
Yes I do live in The United States…
I have my follow up appointment with the GP coming up soon.
It was the nurse who read me my results who said he doesn’t think
that I have it due to the test results.
Fortunately there is an Early Arthritis Clinic in the city that
I live in. I’ll beg for an appointment with them since they need a
doctors referral in order to get an appointment..
I have no obvious signs right now. No swelling. Nothing
but the pain itself. My family members think I am being a
hypochondriac. The worst part about all of this is if it is
RA, than I feel like I may have brought this on myself.
I have been isolating for a couple of years now and not been properly controlling stress and anxiety. Poor diet and lack of exercise when both the Alopecia Areata and the joint pain started…
I’m afraid that I may have triggered this myself and that makes me feel just absolutely awful.