Decoding the Laboratory tests for Rheumatoid Arthritis

Join Dr. Diana Girnita, an experienced rheumatologist, as she decodes the laboratory tests used for diagnosing Rheumatoid Arthritis (RA). In this episode, Dr. Girnita explores different types of laboratory tests and how are they helpful in making a diagnosis. Dr. Girnita is teaching you about the tools that your rheumatologist will use to make the diagnosis and get you helped.

Key Points Covered:

• Clinical Diagnosis Over Laboratory Tests: Emphasis on the importance of clinical signs and symptoms in diagnosing RA rather than relying solely on lab results.
• Case Study Illustration: Alexandra's experience post-pregnancy highlights common RA symptoms, underscoring the need for timely diagnosis and treatment.
• Delay in Seeking Specialist Care: Discussion on the tendency for patients to delay seeking specialist care for RA symptoms.
• Common Blood Tests for RA Diagnosis: Overview of key blood tests including markers of inflammation (ESR, CRP), Rheumatoid Factor (RF), and anti-CCP antibodies.
• Ruling Out Other Conditions: Importance of additional tests to differentiate RA from conditions that mimic its symptoms.
• Debate Surrounding ANA Test: Insight into the ongoing debate over the relevance of the ANA test in diagnosing autoimmune diseases like RA.

Whether you're newly diagnosed or a seasoned warrior against arthritis, 'Decoding RA' is your companion on the journey to understanding, managing, and ultimately thriving despite the challenges of autoimmune diseases. Don't let Rheumatoid arthritis go unnoticed. 

Stay tuned for the next episode!

Transcript

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Welcome to Thriving with Arthritis, the podcast that empowers you to live a better life, despite all the challenges of arthritis and autoimmune diseases. I am Dr. Diana Granita, your host, and a rheumatologist with over 20 years of clinical and research experience. With each episode, you will learn the most valuable information, the latest research, and many practical lifestyle options that will empower you. to fight arthritis.  Whether you're newly diagnosed or have been living with arthritis for many years, this podcast is here to support you every step of the way.

Let's begin. 



Today we're going to talk about something that a lot of my patients will ask. 

What are the blood work that you're going to order to diagnose me with rheumatoid arthritis?

I'm going to start by  telling you a story, as I usually do, a story of one of my patients.

Her name was Alexandra, and Alexandra was 31 years old when she came to my practice.  She was a new mom, and she recently welcomed in her family a bundle of joy, a girl that she named Sheila. 

Three months after giving birth, Alexandra started to experience joint pain in her wrist, in her hands. She started to have swelling in her wrist, and she had severe morning stiffness. 

Even the simplest task became incredibly challenging, like lifting her precious baby to breastfeed.  Because she was concerned about these new symptoms, she called her primary care physician, who after evaluating her, he ordered a few blood tests, and he saw that the markers of inflammation were high.  

He referred her to my office. 

I continue the evaluation and in about one week after I had the results of her test, I asked her to come back for discussion and to initiate treatment. 

Now, Alexandra's story is not unique. Unfortunately, many patients battle pain, swelling and stiffness for months or even years before they come to my office. 

You might think that this is easy, but most patients, they do encounter a lot of resistance from getting a referral to a specialist.  

Many patients will think that this is something that is temporary, it's gonna go away. 

So they take a few painkillers, like anti inflammatories that you find over the counter, which can help.

No doubt, they do help. 

There are other patients that will just blame their age, or they blame the fact that they overuse their joints.   Initially, patients get evaluated by their primary care physicians, who will examine them, and then will order the initial set of labs or x rays.



You have to understand that rheumatoid arthritis, despite all the testing that we will order  remains a clinical diagnosis.  

And a positive test without clinical signs or symptoms has very little value to none in the setting of  evaluating you for a diagnosis. 

On the other hand, A classic picture of rheumatoid arthritis, like we discussed in the previous episodes, with bilateral joint pain, with swelling on both hands or both feet or both knees at the same time. 

That classic picture of rheumatoid arthritis has much more value than negative tests. 

I know that you must be confused at this point, but I want to tell you that laboratory tests and imaging tests are far from perfect. 

I will walk you through the most common and most relevant blood tests and imaging tests that I order to diagnose patients with rheumatoid arthritis. 



Now what are the most common blood tests that we order for rheumatoid arthritis? 

Let's discuss them. 

The number one are markers of inflammation, like sedimentation rate or C reactive protein. 

Those are two markers that are usually ordered by your primary care physician.  

And usually, in patients with active disease, with joint pain, with swelling, one or both of these markers will be elevated. 

There might be other patients where both SED rate or sedimentation rate and C reactive protein are normal. 



The number two   laboratory test is called rheumatoid factor.  

This test is positive in about 60 to 70 percent of patients with rheumatoid arthritis. 

But once again, There might also be people with rheumatoid arthritis where this test is negative.



And the fact that you have this test negative will not rule out or exclude the possibility for you to have rheumatoid arthritis.

But it is also important to understand that a positive rheumatoid arthritis test or a positive rheumatoid factor test is also seen in other diseases. And I'm going to give you a few examples, Sjogren's disease, infections like hepatitis B or C, lymphomas, and even in normal people. 



Now we'll talk about another blood work that we do for patients with rheumatoid arthritis, and those are called anti CCP antibodies.

This test, the anti CCP antibodies, is often ordered along with the rheumatoid factor test.  But the specificity of this test, the anti CCP, is over 90%.  Now what does it mean for you?



If the test is negative, then the likelihood of you having rheumatoid arthritis is very small.

When both tests, rheumatoid factor and anti CCP antibodies are positive, patients are most likely diagnosed with rheumatoid arthritis. 

But that is not all.

There are other tests that we do to rule out other conditions that can mimic inflammation or inflammatory arthritis.



 I'm going to give you a couple of examples. 

Infections, for example. 

Infections with spirovirus with hepatitis B, C, TB, Lyme disease, HIV can also mimic rheumatoid arthritis. 



They can even cause a positive rheumatoid factor test.

That's why. Most of the time, we do order tests to evaluate you for such infections.

Because if you have an exposure to a child 

that goes to kindergarten, you might be exposed to parvovirus. And that's why you might have a disease that looks like rheumatoid arthritis, but it's not. 

If you recently had blood transfusions, then you are at risk to get hepatitis B or hepatitis C. 

If you recently changed your sexual partner, that will increase your risk to get HIV, and that's why we test you for this disease as well.

If you are in the woods and you got a tick bite, then you can develop Lyme disease, which can many times look like rheumatoid arthritis.



The last test that I want to talk about is the ANA test, or the antinuclear antibody test.  

In my medical community, there is an ongoing debate about whether we should or we should not order a positive ANA test.

I'm going to give you a couple of reasons that I consider important before I get this test.

I do want to rule out other autoimmune diseases  that can look like rheumatoid arthritis. For example, patients with lupus or Sjogren, they both can look like rheumatoid arthritis, but it's important to understand if there is a difference between those. 

Now when I want to adjust therapy, if the patient has an anti nuclear antibody test positive.

Then I tend to avoid certain treatments like TNF inhibitors, such as Humira or Embryol 

And if the ANA test is negative before treatment and then it becomes positive, then I know that it was negative and I can make certain correlations. 



Now you know what are the most common laboratory tests that we do to diagnose you with rheumatoid arthritis. And I hope that clarifies for you that not always a laboratory test will make a diagnosis  and your symptoms are so much more important when we evaluate you.  I have many patients in my practice that came with negative blood work. 

but they had the symptoms of rheumatoid arthritis.  And I will invite my patients to tell you the stories how they struggle to find the diagnosis, because many doctors, they look more at the computer, at the blood work test, than they listen to the patients. And I know that is sad, but that doesn't happen in my practice, rheumatologist on call.



I hope that you enjoyed this episode. You learned a lot. And I hope to see you in my next podcast episode.

Don't forget to leave me a comment. 

Leave me feedback. And ask your questions. 

 Because I am listening to what you want to know about rheumatoid arthritis, psoriatic arthritis, and many of the forms of inflammatory arthritis, and not only. 

And with that, thank you, and I will see you in the next episode.



 Thank you for joining Thriving with Arthritis podcast. If you find today's episode valuable, please subscribe. Consider to leave us a review as your feedback helps us improve and reach out more people like you. Remember, you are not alone in your journey with arthritis and autoimmune diseases. Together, we can learn, grow, thrive, and not just survive.

Stay tuned for our next episode where we will dive deeper into what's next. More topics that will matter to you. Until then, keep thriving!