The Role of the Laboratory in the Diagnosis of Rheumatoid Arthritis
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The following questions were submitted by viewers and answered by the presenter, Melissa Snyder, PhD, from the Division of Division of Clinical Biochemistry and Immunology at Mayo Clinic in Rochester, Minnesota. Questions are presented as submitted (unedited).
Is Mayo Rochester using the 3rd generation anti-CCP test and is this what is used in the Mayo Clinic Health System?
I don’t know about the Mayo Health System, but the lab in Rochester is using the 3rd generation assay for anti-CCP. The labs at Mayo Medical Laboratory New England and at the Florida campus perform anti-CCP testing, and they are using the 3rd generation kit also.
In the 4th slide you list the environmental risk factors. Could smoking cessation cure/reverse the clinical symptoms?
Unfortunately, smoking cessation will not cure the disease or reverse the clinical symptoms. The link between smoking and RA is clear (smoking is a risk factor), but the mechanism is largely unknown. However, it is believed that smoking may induce citrullination of proteins and peptides, which leads to an immune response against these epitopes. Part of this immune response is the anti-CCP antibodies that we can measure in the lab. Once the immune response is activated, however, it doesn’t stop, even if smoking is stopped. In addition, once the damage to the joints and other organs occurs (due to the activation of the immune system), the damage cannot be reversed. This is why most rheumatologists believe that treatment during the early stages of the disease is critical in preventing the immune-mediated irreversible tissue damage.
How important is the lab for the ongoing clinical management of a diagnosed RA patient?
Unfortunately, the lab does not play a large role in monitoring RA patients. The titer of neither anti-CCP antibodies nor rheumatoid factor (RF) change with disease course. In other words, the amount of antibody doesn’t increase with an increase in disease activity nor does the amount decrease with response to therapy. As part of monitoring patients with RA, clinicians may order general markers of inflammation, such as C-reactive protein (CRP) or erythrocyte sedimentation rate (ESR). However, treatment will be based almost exclusively on the clinical presentation of the patient.