Measuring and Tracking Rheumatoid Arthritis Disease Activity
Why is measuring the disease activity of rheumatoid arthritis important?
Regular and systematic assessment of rheumatoid arthritis (RA) disease activity is important because it allows you and your doctor to determine how well treatment is working and whether changes to the treatment plan are necessary. The goal of RA treatment is to reduce symptoms and prevent irreversible joint damage.
In a recent survey of RA patients only 55% of respondents reported hat their physician routinely measured disease activity during their visits.
How is RA disease activity measured?
A Disease Activity Score (DAS) is used to measure ongoing inflammation, symptoms, and/or joint damage and there are several different ways to monitor disease activity:
- Non-specific lab tests: Lab tests that measure two indicators of inflammation – the erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) can be used to assess disease activity.
- DAS28 (Disease Activity Score with 28 joint counts). The DAS28 score combines a count of tender and swollen joints, an assessment of health, and lab tests to identify inflammation.
- Vectra DA: A blood test that allows doctors to test for several biological markers (or biomarkers) of rheumatoid arthritis activity simultaneously.
What is the Vectra DA blood test?
Vectra DA is an advanced blood test for adults that measures RA disease activity. Vectra DA scores are used to track RA disease activity on an ongoing basis and may help identify the risk of future joint damage.
How Does Vectra DA Measure RA Disease Activity?
Vectra DA detects what’s going on below the surface by assessing multiple biological pathways that drive RA disease. Vectra DA provides information about RA that goes beyond physical symptoms
- The Vectra DA test measures the levels of 12 bio-marker proteins in the blood that have been linked to RA disease activity—and then combines them into a single score (between 1 and 100).
- The single score generated by Vectra DA classifies RA into low, moderate, and high disease activity – the lower the score, the better.
- Vectra DA also reports a Minimal Important Difference (MID) from one score to the next so you know if the change in your score is significant.
How accurate is Vectra DA?
In order to evaluate the Vectra DA test researchers compared the DAS28-CRP score with Vectra DA in 426 patients and found that the Vectra DA test results were statistically significantly correlated with the DAS28-CRP results in both seropositive and seronegative patients.
Among patients who started treatment with methotrexate or an anti-TNF drug, changes in the Vectra DA score provided information about response or non-response to treatment.
Additional Research Results on DAS That Might be Helpful
Is Vectra DA covered by insurance?
Medicare fully covers Vectra DA with no copayment* or deductible. Crescendo Bioscience’s goal is to ensure that cost is not a barrier for anyone with RA who wants a Vectra DA test – call 1-877-RHEUMDX (1-877-743-8639) to learn about financial assistance. See page 3 of this document for more information Ask your doctor about ordering Vectra DA for you *Medicare Advantage plans may require a copay.
ESR and CRP Lab Results are Poor Measures of Disease Activity and Often Inconsistent with Clinical Evaluations of RA.
In a report published in Arthritis Research and Therapy, researchers found that a common criterion for entry into rheumatoid arthritis (RA) clinical trials—elevated levels of what is termed acute phase reactant (APR)—often exclude patients who have active disease as measured by patient and physician assessments. Perhaps more importantly, many physicians rely on APR’s to help them determine RA disease activity. Better laboratory measures are needed to measure RA disease activity.
Disease progression in RA is often evaluated using a number of parameters, including imaging, laboratory results, as well as an assessment of tender and swollen joint counts and patient and physician assessments, which is referred to as clinical disease activity index (CDAI). The key laboratory marker, elevated APR, actually comprises two measurements, that of C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR). The difficulty in evaluating RA progression, and, therefore determining if a patient is a candidate for a clinical trial, is that many patients may have active disease as measured by the CDAI but have normal lab results, or even discordant results in which CRP is normal and ESR is not, or vice versa. Currently, patients who might have clinical indications for active disease but do not have elevated APR are excluded from clinical trials. This also has significant implications for monitoring and managing therapy of patients outside clinical trials.
This study looked at the baseline characteristics and one-year outcomes of 9,135 RA patients from the Consortium of Rheumatology Researchers of North America (CORRONA) database.
Researchers found that elevated levels of APR at the initial visit did not correlate with disease activity as determined by joint counts and the global assessments of the CDAI clinical evaluation. Specifically, the investigators determined that at the initial visit 58% of the patients with active RA had neither elevated ESR nor CRP. Further, of those with active RA, only 16% had elevated levels of CRP and ESR; 26% had one or the other elevated. Reliance on the APR values, researchers concluded, caused some patients with active disease to be excluded from clinical trials that they otherwise would be well suited for. Investigators further concluded after one year follow-up visits that obtaining initial APR levels and tracking them over time was an appropriate and useful protocol.
Other laboratory assessments of disease activity have been and are being developed. One newer way to measure disease activity is the Vectra DA test, which is a blood test that allows doctors to test for several biological markers (or biomarkers) of RA simultaneously. Vectra DA measures the levels of 12 proteins in the blood—biomarkers that have been linked to RA disease activity—and then combines them into a single score (between 1 and 100) that classifies the current level of RA disease activity as “low”, “moderate”, or “high”.
To compare Vectra DA results with conventional, clinical measures of RA disease activity, researchers evaluated 426 patients. One of the conventional measures of disease activity that was assessed was the DAS28-CRP. The DAS28-CRP involves a count of tender and swollen joints, patient-reported health measures, and a lab test to identify inflammation.
- The Vectra DA test results were statistically significantly correlated with the DAS28-CRP results in both seropositive and seronegative patients. Seropositive patients were those who tested positive for rheumatoid factor and/or anti-cyclic citrullinated peptide antibodies.
- Among patients who started treatment with methotrexate or an anti-TNF drug, changes in the Vectra DA score provided information about response or non-response to treatment.
These results validated Vectra DA as an objective measure of RA disease activity. The test is not intended to replace clinical assessment, but may provide additional, complementary information. Improved assessment of RA disease activity could refine treatment decisions and allow for better RA control.
More Accurate Measure of RA Response to Actemra® with Vectra DA® Score and Clinical Assessment of Disease Activity
The Vectra DA® score used in conjunction with clinical assessment may help more accurately measure response to Actemra® (tocilizumab), a biologic treatment, in rheumatoid arthritis (RA). These findings were published in Rheumatology International.
The Vectra DA test provides a multi-biomarker disease activity (MBDA) score that helps determine disease activity in RA. The test measures 12 biomarkers (or proteins) present in the serum (the liquid part of blood) that are associated with disease activity in RA. When Vectra DA measures these12 proteins, the test then combines them into a single score (between 1 and 100) that classifies the current level of RA disease activity as “low”, “moderate”, or “high.” Earlier research has suggested that some RA treatments result in similar MBDA scores and clinical disease activity (DA) scores (a doctor’s assessment of disease activity, such as counting the number of tender and swollen joints).
To better understand how Vectra DA and clinical DA scores reflect response to treatment, researchers evaluated these measures of disease activity in 78 RA patients treated with Actemra. At specific times, the patients had clinical DA assessed and blood collected for Vectra DA serum testing. The researchers looked for links between scoring and DA assessment and outcomes.
In the majority of patients, or 77.1%, Vectra DA score and clinical DA score placed patients at the same level of RA disease activity (low, moderate, or high) at the beginning of the study period. At a six-month follow-up, however, agreement in disease activity level between Vectra DA and clinical DA score was reduced to 23.7%. At checkpoints during the course of the study (one, three, and six months), there were smaller signs of reduced disease activity in Vectra DA scores than in clinical DA scores.
Looking specifically at Vectra DA results, researchers found that one particular inflammatory protein, interleukin-6 (IL-6), increased in most patients during treatment with Actemra. This increase in IL-6 may have been a factor in the decline in agreement between Vectra DA and clinical DA scores described above.
These findings suggest that when assessing RA disease activity in patients undergoing treatment with Actemra, doctors may get more accurate results using both MBDA scores and clinical measures. The rising levels of IL-6 observed during Actemra treatment may result in an inaccurate measure of actual disease activity.
Joint inflammation and damage are important determinants of disability in patients with rheumatoid arthritis (RA).
The multi-biomarker disease activity (MBDA) test (Vectra DA) analyzes 12 serum protein biomarkers and uses a validated algorithm to generate a score that represents the level of RA disease activity on a scale of 1 to 100 with categories of low (<30),>44).
Information about the level of disease activity allows doctors to monitor the response to treatment and to adjust treatment as needed. Commonly used measures of disease activity are the DAS28 (Disease Activity Score with 28 joint counts), the erythrocyte sedimentation rate (ESR) and levels of C-reactive protein (CRP). The DAS28 involves a count of tender and swollen joints, your own assessment of your health, and lab tests to identify inflammation.
The Vectra DA test allows doctors to test for several biological markers (or biomarkers) of RA simultaneously. Vectra DA measures the levels of 12 proteins in the blood—biomarkers that have been linked to RA disease activity—and then combines them into a single score (between 1 and 100) that classifies your current level of RA disease activity as “low”, “moderate”, or “high”.
The Vectra DA score has previously been found to be associated with identifying a risk for radiographic progression of disease in patients with RA. Doctors recently reported the results of a clinical study evaluating data collected from 6 groups of individuals with RA to see if a large sample size collectively evaluated could establish a relationship between a Vectra DA score and the risk for radiographic progression of RA.(1-10)
The study revealed that a high Vectra DA score was associated with an increased risk for radiographic progression of RA and that a high Vectra DA score was more predictive of progression that a high CRP or DAS39-CRP, two other commonly used measures of disease activity.
Vectra DA® Multi-Biomarker Disease Activity Score Predicts Progression in Rheumatoid Arthritis up to Two Years
The Vectra DA® (MBDA) score multi-biomarker disease activity (MBDA) score appears to help doctors predict the radiographic progression of early rheumatoid arthritis (RA) during the first two years of treatment. Understanding how RA is likely to progress is a critical part of planning optimal treatment. These findings were presented at the 2014 Annual Meeting of the American College of Rheumatology, November 14–19, in Boston, Massachusetts.
Radiographs, or X-rays, are used in patients with RA to measure how the disease is progressing or whether it’s responding to treatment (progression has slowed). This is called radiographic progression; doctors use it to measure joint inflammation and damage over time and determine patterns or changes in activity. In early RA the ability to predict what types of changes doctors might see on X-ray as RA progresses could help them choose effective therapies. The Vectra DA® score uses 12 serum (the liquid part of blood) proteins to measure disease activity in RA.
Researchers with the Swedish Farmacotherapy (SWEFOT) trial previously reported that Vectra DA® scores could help predict radiographic progression of RA during the first year of treatment. More recently, researchers with the SWEFOT trial evaluated whether Vectra DA® scores could help prediction RA progression beyond the first year of treatment—specifically, over the first two years of treatment, with the aim to help doctors plan treatment.
Researchers followed radiographic progression of patients with early RA for up to two years of treatment. A total of 220 patients were assessed from the start of the study through years one and two of treatment and another 133 patients from years one through two of treatment. The researchers monitored Vectra DA®scores against radiographic progression while also measuring disease activity with DAS28 (a disease activity measuring instrument) and C-reactive protein (a marking of inflammation).
The researchers found that patients with higher Vectra DA® scores at the start of the study whose Vectra DA® score remained high at three or 12 months had the highest risk of radiographic progression between the start and one or two years. On the other hand, patients with initial high Vectra DA® scores that had dropped to low at the three-month checkup had a low risk of radiographic progression between years one and two. Patients whose Vectra DA® scores remained low during the first year of study didn’t progress radiographically within two years. Those who started with mid-range Vectra DA® scores that then dropped to low at three and 12 months didn’t progress either.
The researchers concluded that the Vectra DA® score before treatment in early RA appeared to help predict radiographic progression over two years. Evidence that Vectra DA® scores can help predict radiographic progression through year two of treatment further supports the score as an valuable resource in planning treatment for patients with early RA.
 Hambardzumyan K, Bolce R, Saevarsdottir S, et al. In Early Rheumatoid Arthritis, the Multi-Biomarker Disease Activity Score at Different Time-Points is Predictive of Subsequent Radiographic Progression. 2014 American College of Rheumatology Annual Meeting. Abstract 364.
 Hambardzumyan K, Bolce R, Saevarsdottir S, et al. Pretreatment Multi-Biomarker Disease Activity Score and Radiographic Progression in Early RA: Results from the SWEFOT Trial. *Annals of Rheumatoid Diseases.*doi:10.1136/annrheumdis-2013-204986.
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- Kay, Jonathon, et al. Clinical disease activity and acute phase reactant levels are discordant among patients with active rheumatoid arthritis: acute phase reactant levels contribute separately to predicting outcome at one year. Arthritis Research and Therapy. Volume 16, issue 1. Published online February 3, 2014.
- Reference: Curtis JR, van der Helm-van Mil AH, Knevel R et al. Validation of a novel multi-biomarker test to assess rheumatoid arthritis disease activity. Arthritis Care & Research. Early online publication June 26, 2012.
Reiss WG, Devenport JN, Low JM, et al. Interpreting the multi-biomarker disease activity score in the context of tocilizumab treatment for patients with rheumatoid arthritis. Rheumatology International[online publication]. May 31, 2015.