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Our Guide to RA testing

Rheumatoid Arthritis

Harnessing science to improve the health and lives of people with rheumatoid arthritis (RA).

 

 

Rheumatoid arthritis testing

Rheumatoid arthritis affects an estimated 1.5 million people in the United States.1 For most people with RA, early diagnosis and treatment can control joint pain and swelling and lessen joint damage.

Labcorp is your trusted single-source solution for RA testing, from RA diagnosis to disease activity monitoring and treatment management.

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RA Diagnosis

Early RA diagnosis and initiation of disease-suppressing therapy may improve clinical outcomes and reduce the accrual of joint damage and disability.2 Labcorp offers several RA-specific markers that, when used in combination, provide industry-leading sensitivity and help support an early diagnosis of RA. Prognosis is dependent on early, accurate diagnosis and establishing an effective treatment plan.3 Diagnosis and classification of RA has relied heavily on anti-cyclic citrullinated peptide (Anti-CCP) and rheumatoid factor (RF) IgM.2 New markers are available to better identify patients with RA, stratify patients for risk of joint destruction and/or radiographic progression, and monitor disease activity and effectiveness of treatment.

RA Diagnosis

RheumAssure®

Labcorp’s RheumAssure panel contains Rheumatoid Factor (RF), Cyclic Citrullinated Peptide (CCP) Antibodies, and 14-3-3 eta protein tests. 

  • Used together, these three markers are able to diagnose established RA with a sensitivity of 88-96% and early RA with a sensitivity of 78-92%.3,4 
  • Elevation of one or more RheumAssure markers is consistent with an RA diagnosis, and if all three markers are negative, a diagnosis is less likely
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RA Diagnosis

RAdx6 Profile

The RAdx6 combines four novel markers (14-3-3 eta, Anti-Sa, Anti-CEP-1, and Anti-CarP) with two traditional markers (Anti-CCP and RF-IgM) to enhance diagnosis in early or established RA and help predict disease severity. 

  • Disappearance or decrease of 14-3-3 eta and/or Anti-Sa with treatment is associated with less radiographic progression
  • In preclinical RA, Anti-CEP-1 with Anti-CCP antibodies significantly raises the risk of imminently developing clinical RA
  • Anti-CarP may predict the development of RA independently of Anti-CCP and may be present years before the onset of symptoms in RA
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RA Diagnosis

SeroNeg RAdx4 Profile and RA Profile (RF and Anti-CCP) reflex to SeroNeg RAdx4

These diagnostic and prognostic panels are designed to complement traditional RF and Anti-CCP testing. The profile consists of 14-3-3 eta, Anti-Sa, Anti-CEP-1, and Anti-CarP. 

  • Enhances RA diagnosis and helps predict disease severity
  • Helps identify RA in Anti-CCP-negative and IgM-RF-negative patients and in the diagnosis of early RA

SeroNeg RAdx4 Profile
RA Profile reflex to SeroNeg RAdx4

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Disease Activity Monitor and Prognostic Tool

Vectra® by Labcorp

Achieving a state of disease remission in rheumatoid arthritis (RA) is a primary treatment goal. Until the desired treatment target is reached, drug therapy should be adjusted at least every three to six months. The desired treatment target should be maintained throughout the remaining course of the disease. Vectra provides an objective measure of RA inflammation and can be used to complement other disease activity measures.

RA Monitor & Prognosis

Vectra®

Vectra is an advanced blood test that objectively measures inflammation caused by rheumatoid arthritis. 

Vectra provides a personalized score by measuring 12 biomarkers and incorporates information on age, gender and adiposity to measure RA inflammation and predict future risk of radiographic progression.5

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RA Monitor & Prognosis

Vectra Cardiovascular Risk

Vectra Cardiovascular Risk provides a personalized assessment of inflammation to predict an RA patient’s risk of a cardiovascular event in the next 3-years.6

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Vectra is intended to be used at therapy initiation, change in drug therapy, and to monitor a patient once they achieve low disease activity

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RA Treatment Monitoring

Although RA treatment is multifaceted, medications play an important role in patient management. Newly developed laboratory assays aid physicians in monitoring use and maximizing effectiveness of both disease-modifying anti-rheumatic drugs (DMARDs) and biologics.

RA Treatment Monitoring

Methotrexate Polyglutamates

Methotrexate (MTX) is subject to wide pharmacokinetic variability. About 30% of patients do not respond to MTX treatment or experience adverse effects.7 Testing for MTX PGs can help assess patient compliance and determine correct dosing to achieve therapeutic levels and clinical response.8

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RA Treatment Monitoring

Hydroxychloroquine, Whole Blood

Hydroxychloroquine (HCQ) concentrations may be useful in achieving maximal clinical benefit while minimizing long-term retinal toxicity in lupus and other chronic autoimmune diseases. Monitoring HCQ may also improve adherence.

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RA Treatment Monitoring

Thiopurine Drug

Thiopurine-related testing may be used to assess dosing before and during treatment, as well as to identify patients who may be at risk for drug toxicity.9 The FDA-approved label recommends testing consideration for the most common TPMT gene mutations (genotype) or TPMT activity (phenotype) before beginning treatment due to potentially severe bone marrow toxicity.

TPMT Genotyping
TPMT Enzyme Activity

Monitoring Biologics 

Labcorp offers serum measurement of drug and anti-drug antibodies for patients on biologic drug therapy. Drug and anti-drug antibody levels provide the pharmacokinetic and immunogenic assessment that discerns the underlying mechanism of an inadequate response to biologic drug. Testing may be ordered at any time during therapy, though sample collection before the next infusion or injection is recommended.

Monitoring Biologics

DoseASSURE™

Labcorp’s DoseASSURE™ suite of tests includes the following drugs and anti-drug antibodies:   

Adalimumab and Anti-Adalimumab Antibody ADL 
Certolizumab and Anti-Certolizumab Antibody CTZ
Etanercept and Anti-Etanercept Antibody ETN 
Golimumab and Anti-Golimumab Antibody GOL
Infliximab and Anti-Infliximab Antibody IFX
Rituximab and Anti-Rituximab Antibody RTX
Ustekinumab and Anti-Ustekinumab Antibody UST

Want to Speak to your Labcorp Representative?
 

Rheumatology Services Hotline: 800-338-1918

Vectra® Customer Service: 877-743-8639

References

  1. Handout on Health: Rheumatoid Arthritis. National Institute of Arthritis and Musculoskeletal and Skin Diseases Website http://www.niams.nih.gov/health_info/Rheumatic_Disease/default.asp#ra_2 . Accessed February 25, 2014.
  2. Aletha D, Neogi T, Silman AJ. 2010 rheumatoid arthritis classification criteria. Arthritis Rheum. 2010;62(9):2569-2581.
  3. Maksymowych WP, Naides SJ, Bykerk V, Siminovitch KA, et al. Serum 14-3-3η is a novel marker that complements current serological measurements to enhance detection of patients with rheumatoid arthritis. J Rheumatol. 2014 Nov;41(11):2104-13. doi: 10.3899/jrheum.131446. Epub 2014 Aug 15. PMID: 25128504.
  4. Maksymowych WP, Boire G, van Schaardenburg D, et al. 14-3-3η Autoantibodies: Diagnostic Use in Early Rheumatoid Arthritis. J Rheumatol. 2015 Sep;42(9):1587-94. doi: 10.3899/jrheum.141385. Epub 2015 Jul 15. PMID: 26178283.
  5. Curtis, J.R., Weinblatt, M.E., Shadick, N.A. et al. Validation of the adjusted multi-biomarker disease activity score as a prognostic test for radiographic progression in rheumatoid arthritis: a combined analysis of multiple studies. Arthritis Res Ther 23, 1 (2021). https://doi.org/10.1186/s13075-020-02389-4 .
  6. Curtis, J.R., Xie, F., Crowson, C.S. et al. Derivation and internal validation of a multi-biomarker based cardiovascular disease risk prediction score for rheumatoid arthritis patients. Arthritis Res Ther 22, 282 (2020). https://doi.org/10.1186/s13075-020-02355-0 .
  7. Goodman S. Measuring methotrexate polyglutamates. Clin Exp Rheumatol. 2010 Sep-Oct; 28 (5 Suppl 61): S24-S26.
  8. De Rotte MCFJ, den Boer E, de Jong PHP, et al. Methotrexate polyglutamates in erythrocytes are associated with lower disease activity in patients with rheumatoid arthritis. Ann Rheum Dis. 2013;0:1-7.
  9. Chevaux JB, Peyrin-Biroulet L, Sparrow MP. Optimizing thiopurine therapy in inflammatory bowel disease. Inflamm Bowel Dis. 2011 Jun; 17(6): 1428-1435.

 

 

What is rheumatoid arthritis?

Rheumatoid arthritis is a chronic inflammatory disease that causes joint pain, stiffness, swelling and decreased joint movement. The most commonly affected joints are the small joints in the hands and feet. The synovial lining of the joint may become inflamed, causing long-lasting or chronic pain, lack of balance or deformity.1

  • RA affects an estimated 1.5 million people in the United States

  • RA is the most common type of autoimmune arthritis

  • Early diagnosis and treatment can help control joint pain and swelling and lessen joint damage for most people with RA

  • Labcorp offers a variety of tests to aid in the diagnosis, management of treatment, and monitoring of disease activity

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RA diagnosis

Early diagnosis is key to slowing the progression of the disease and preventing permanent joint damage, also known as radiographic progression.  A clinician will review, assess and discuss symptoms, perform a physical examination, order lab tests and may consider imaging tests, such as an X-ray or ultrasound.

Blood Tests used for RA Diagnosis

Traditional blood panels for RA diagnosis

  • Complete Blood Count (CBC) is used to check your overall health and check for abnormalities2
  • Erythrocyte sedimentation rate (ESR) (erythrocyte sedimentation rate) measures the rate red blood cells settle. Higher rates may indicate inflammation3
  • C-reactive protein (CRP) measures a protein made in response to inflammation4
  • Rheumatoid Factor (RF) measures proteins produced by your immune system that can attack healthy tissue5
  • Anti-cyclic citrullinated peptide (Anti-CCP) measures proteins made by the immune system that can attack healthy cells, which can indicate bone damage6
  • Antinuclear antibody (ANA) measures antibodies that your body makes to fight foreign substances7

Labcorp Specific RA Diagnosis Testing Panels

  • RheumAssure® contains Rheumatoid Factor (RF), Cyclic Citrullinated Peptide (CCP) Antibodies, and 14-3-3 eta protein tests
  • RAdx6 Profile combines four novel markers (14-3-3 eta, Anti-Sa, Anti-CEP-1, and Anti-CarP) with two traditional markers (Anti-CCP and RF-IgM) to enhance diagnosis in early or established RA and help predict disease severity
  • SeroNeg RAdx4 Profile and RA Profile (RF and Anti-CCP) reflex to SeroNeg RAdx4 These diagnostic and prognostic panels are designed to complement traditional RF and Anti-CCP testing. The profile consists of 14-3-3 eta, Anti-Sa, Anti-CEP-1, and Anti-CarP
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Testing for RA treatment decisions

Your healthcare provider will determine the best course of treatment. Prior to prescribing treatment, a series of tests will be need in order to ensure the treatment is right for you.

  • If your provider is considering putting you on a biologic, they will run the following tests: CBC, CMP, TB, and a Hep B Screening
  • If your provider is suggesting thiopurine as a treatment plan, they will order the following tests: CBC, and TPMT Enzymes/TPMT Genetics
  • When Methotrexate is recommended, the following tests will be ordered: CBC and CMP
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Monitoring disease activity with Vectra by Labcorp

Once your healthcare provider has made an RA diagnosis, it is essential to stay engaged with them and discuss treatment options. Monitoring your diseases and symptoms is key to achieving the best outcome possible.

Vectra by Labcorp is an advanced blood test that objectively measures inflammation caused by rheumatoid arthritis. Your Vectra score is personalized to you. Because people tend to have higher or lower levels of inflammation based on their age, gender, and level of body fat, each patient’s score is adjusted to account for these differences. Vectra reveals the severity of your RA, how well your current treatment is working and is the best predictor of future joint damage.

  • The scores range from 1-100, with lower scores indicating less RA inflammation and higher scores indicating more inflammation. Patients with Vectra scores in the low range are at a lower risk of future joint damage. Patients in the high and moderate categories are considered to have uncontrolled inflammation and may require treatment modification
  • Knowing your risk for joint damage can help you and your doctor assess the treatment plan that’s right for you
  • The Vectra test should be ordered as early as possible to establish a baseline score to compare with future Vectra scores. Changes in your score of 8 or more points in the moderate or high range indicates a change in your clinical response to therapy. This should result in a conversation with your provider about how to address the change
  • Vectra can be used after a change in drug therapy to measure your response to the new therapy

Using a molecular assessment, along with assessments by you and your doctor, can provide the most complete view of your RA inflammation.

Between appointments, you may experience frequent ups and downs with your rheumatoid arthritis. Tracking your RA symptoms can help you spot trends in how you feel and function. Having this information can help you and your provider see the bigger picture and know if your treatment plan is working well.8

Learn more about your Vectra score by downloading the Vectra by Labcorp patient brochure 

Take a deeper look at your Vectra test results with the Vectra post-test patient education tool 

UNDERSTAND YOUR COST

You may request an estimate of your out-of-pocket cost for the Vectra test ordered by your provider. You can request the estimate by phone* or during your visit to any Labcorp patient service center for blood draw. 

*Our dedicated Labcorp rheumatology service team is waiting to assist
(call center hours are 8am – 7pm ET Monday- Friday)

Call this number if you have insurance:

(877) 348-5191

Call this number if you do not have insurance:

(855) 522-2677, options 2-3

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RA treatment effectiveness

Newly developed laboratory tests help you and your healthcare provider in monitoring use and maximizing effectiveness of both disease-modifying anti-rheumatic drugs (DMARDs) and biologics.

  • DoseASSURE® Biologic TDM - If an inadequate response to a biologic is suspected, your healthcare provider may recommend DoseASSURE® Biologic TDM to understand your immune response to the drugs. Testing may be ordered at any time during therapy, though sample collection before the next infusion or injection is recommended
  • Methotrexate (MTX) Polyglutamates (PG) - About 30% of patients do not respond to MTX treatment or experience adverse effects.9 Testing for MTX PGs can help determine correct dosing to achieve desired therapeutic levels and clinical response10
  • Thiopurine Metabolites - Thiopurine-related testing may be used to assess dosing before and during treatment, as well as to identify you may be at risk for drug toxicity11
  • Vectra can be used after a change in drug therapy to measure your response to the new therapy

RA risks

Patients with RA have approximately 50% greater risk for cardiovascular disease (CVD) compared to the general population, and CVD is the leading cause of death in RA patients.12,13

30% of cardiovascular risk in patients with RA is attributed to systemic inflammation and other RA-related factors. 14

It is important to monitor and learn your risk for a cardiovascular event in the next three years with Vectra Cardiovascular (CV) Risk.

Vectra CV Risk is a validated test that measures proteins in the blood, called biomarkers, to assess your RA inflammation and predict your risk of having a major cardiovascular event (e.g., heart attack or stroke) in the next three years. Vectra CV Risk is the only multi-biomarker based CV risk predictor for RA patients.15

Vectra CV Risk provides an actionable result at point of care that highlights the role of reducing systemic inflammation associated with RA. Vectra CV can be added to your Vectra test for those who are 40 years old or older.

Ask your healthcare provider about the Vectra CV Risk assessment and learn more with the RA and cardiovascular risk sheet.

Additional resources
 

 

References

  1. Centers for Disease Control and Prevention. Rheumatoid Arthritis (RA). Accessed July 27, 2020. https://www.cdc.gov/arthritis/basics/rheumatoid-arthritis.html.

  2. National Library of Medicine. Blood count test. Medlineplus.gov. Accessed December 14, 2022. https://medlineplus.gov/bloodcounttests.html.

  3. National Library of Medicine. Erythrocyte Sedimentation Rate (ESR). Medlineplus.gov. Accessed December 14, 2022. https://medlineplus.gov/lab-tests/erythrocyte-sedimentation-rate-esr/.

  4. National Library of Medicine. C-Reactive Protein (CRP) test. Medlineplus.gov. Accessed December 14, 2022. https://medlineplus.gov/lab-tests/c-reactive-protein-crp-test/

  5.  National Library of Medicine. Rheumatoid Factor (RF) test. Medlineplus.gov. December 14, 2022. https://medlineplus.gov/lab-tests/rheumatoid-factor-rf-test/.

  6. National Library of Medicine. CCP Antibody tests Medlineplus.gov. December 14, 2022. https://medlineplus.gov/lab-tests/ccp-antibody-test/.

  7.  National Library of Medicine. ANA (Antinuclear Antibody) test. Medlineplus.gov. December 14, 2022. https://medlineplus.gov/lab-tests/ana-antinuclear-antibody-test/.

  8. Grainger R, Townsley H, White B, Langlotz T, Taylor WJ. Apps for People With Rheumatoid Arthritis to Monitor Their Disease Activity: A Review of Apps for Best Practice and Quality. JMIR Mhealth Uhealth. 2017;5(2):e7. Published 2017 Feb 21. doi:10.2196/mhealth.6956

  9. Goodman S. Measuring methotrexate polyglutamates. Clin Exp Rheumatol. 2010 Sep-Oct; 28 (5 Suppl 61): S24-S26.

  10. De Rotte MCFJ, den Boer E, de Jong PHP, et al. Methotrexate polyglutamates in erythrocytes are associated with lower disease activity in patients with rheumatoid arthritis. Ann Rheum Dis. 2013;0:1-7.

  11. Chevaux JB, Peyrin-Biroulet L, Sparrow MP. Optimizing thiopurine therapy in inflammatory bowel disease. Inflamm Bowel Dis. 2011 Jun; 17(6): 1428-1435.

  12. Aviña-Zubieta JA, Choi HK, Sadatsafavi M, Etminan M, Esdaile JM, Lacaille D. Risk of cardiovascular mortality in patients with rheumatoid arthritis: a meta-analysis of observational studies. Arthritis Rheum. 2008;59(12):1690-7.

  13. Andrews LW. What Rheumatoid Arthritis Does to Your Heart. Healthgrades. https://www.healthgrades.com/right-care/rheumatoid-arthritis/what-rheumatoid-arthritis-does-to-your-heart. Published October 3, 2019. Accessed September 24, 2020.

  14. Crowson CS, Rollefstad S, Ikdahl E, Kitas GD, van Riel P, Gabriel SE, et al. Impact of risk factors associated with cardiovascular outcomes in patients with rheumatoid arthritis. Ann Rheum Dis. 2018;77(1):48-54. 3. Crowson CS, Rollefstad S, Ikdahl E, Kitas GD, van Riel P, Gabriel SE, et al. Impact of risk factors associated with cardiovascular outcomes in patients with rheumatoid arthritis. Ann Rheum Dis. 2018;77(1):48-54.

  15. Curtis JR, Fenglong X, Crowson CS, et al. Derivation and internal validation of a multi-biomarker-based cardiovascular disease risk prediction score for rheumatoid arthritis patients. Arthritis Research & Therapy. Pending publication