Rheumatoid Arthritis, the most prevalent type of bone disease, is mediated by an overreaction of the immune system, and can, therefore, affect virtually every organ system and creating a toxic joint fluid that leads to degradation of the articular bone and eventually to crippling joint damage. Because of the non-specificity of its symptoms, it is difficult to diagnose RA and differentiate it from other ailments.
RA is believed to have both genetic as well as an environmental basis of occurrence. Since the symptoms are varied, a singular test for diagnosis of RA is not possible.
Effective treatment of RA has been impeded by a paucity of accurate diagnostic and prognostic tests, owing to the heterogeneity of the disease. Evaluation of certain genetic biomarkers allows an early detection of susceptible individuals, estimation of severity, selection of therapy, and monitoring of response to therapy.
A biomarker is defined as any parameter (nucleic acids, proteins, sugars, lipids, and metabolites, as well as whole cells or biophysical characteristics of tissues) that can be objectively examined and measured as an indicator of a pathological activity, a pharmacological response or any biological process in general.
Evaluation of erythrocyte sedimentation rate, C-reactive protein (CRP), and rheumatoid factor (RF) indicates inflammation, however, the development of more specific biomarker tests is important.
Polyglutamate Testing
This is a measure of the effectiveness of methotrexate, a most commonly prescribed anti-rheumatic drug. Once it enters the cells, it is converted to methotrexate polyglutamate which perform the therapeutic action. The idea is to help rheumatologists understand whether methotrexate works on the patient and enable them to develop a personalized dosage or determine if a change in medication is required. As 30–40% of patients do not respond to methotrexate, the measurement of methotrexate polyglutamate in the blood is a good indicator to know whether the treatment is adequate or not. The measurement is taken three months after the person begins taking methotrexate.
Vectra DA
This is a blood test that measures 12 biomarkers of RA in one go. The test is not used to diagnose RA but to monitor disease activity. The Vectra DA score can also be relied upon to predict joint damage and flares instead of ultrasound and MRIs.
However, not everyone who has RA needs the test. It’s only needed when there is uncertainty about how active the RA is or if there is a change in treatment required.
Anti-CCP2 Test
This is the second generation of the first anti-CCP test, which has been around since the late 1990s. Antibodies of cyclic citrullinated peptides (CCP) are often present in the early stages of RA, even before its clinical signs appear. The CCP blood test was developed by selecting the CCPs that best detected RA. Being a highly sensitive and specific test, it is more accurate.
Anti-MCV
This blood test checks for antibodies produced in reaction to mutated citrullinated vimentin (MCV), a protein that drives RA.
Because MCV antibodies are highly specific and may be detectable several years before the RA actually manifests, the MCV test is a better predictor of aggressive disease or erosions. In most cases, both the CPP test and MCV test are done along with a test for rheumatoid factor. The test instantly identifies RA patients among patients with other forms of arthritis.
References:
- Biomarkers Track Arthritis Activity
- Early biomarkers of joint damage in rheumatoid and psoriatic arthritis
- Biomarkers for rheumatoid arthritis: Making it personal
- A Multi-biomarker Score Measures Rheumatoid Arthritis Disease Activity in the Best Study
Vitamin D: The One-Molecule Wonder
Current research shows that vitamin D not only betters bone health and provides muscular stability but it also prevents gastrointestinal and neurological ailments. Recently, vitamin D has been shown to play a role in cancer prevention, raising its stature amongst healthcare professionals. Read More..
