InstalabInstalabAn arthritis panel brings together several complementary blood markers to help clarify whether joint pain, stiffness, or swelling is driven by inflammation, autoimmunity, or crystal deposition. No single test can diagnose arthritis on its own. This panel is designed to map the underlying biology so clinicians can narrow the cause and guide next steps.
Rheumatoid factor is an autoantibody, meaning an antibody that targets the body’s own tissues. In rheumatoid arthritis, the immune system becomes misdirected and produces antibodies against proteins in the joints, leading to chronic inflammation and joint damage. Elevated rheumatoid factor increases the likelihood of rheumatoid arthritis, especially in the right clinical context, but it is not specific. It can also be seen in other autoimmune diseases, chronic infections, and even in some healthy older adults. That means a normal value does not rule out rheumatoid arthritis, and a high value does not confirm it on its own.
C reactive protein and erythrocyte sedimentation rate are general markers of inflammation. C reactive protein is a protein made by the liver in response to inflammatory signals such as interleukin 6. It rises quickly when inflammation is active and falls quickly when inflammation resolves. ESR measures how fast red blood cells settle in a tube over one hour. Inflammatory proteins make red blood cells stick together and fall faster, leading to a higher ESR. CRP tends to reflect real time inflammatory activity, while ESR changes more slowly and can remain elevated even after inflammation improves. Both markers are useful for assessing how active an inflammatory arthritis is and for tracking response to treatment, but neither identifies the cause of inflammation.
Uric acid reflects purine metabolism, which is how the body breaks down DNA and certain foods. When uric acid levels are high, crystals can form in joints and trigger gout, a form of inflammatory arthritis caused by crystal induced immune activation rather than autoimmunity. Elevated uric acid supports a diagnosis of gout, especially during recurrent attacks, but levels can be normal during an acute flare. Conversely, some people have chronically high uric acid without ever developing gout. This marker is most useful when interpreted alongside symptoms and joint findings.
The antinuclear antibody screen looks for antibodies directed against components of the cell nucleus. A positive ANA suggests loss of immune tolerance and is commonly seen in systemic autoimmune diseases such as systemic lupus erythematosus, mixed connective tissue disease, and Sjögren syndrome. ANA can also be positive in a small percentage of healthy individuals, particularly women and older adults. A negative ANA makes many systemic autoimmune diseases less likely, while a positive result often prompts more specific antibody testing to clarify the diagnosis.
Taken together, this panel helps distinguish inflammatory arthritis from non inflammatory joint conditions, differentiate autoimmune disease from crystal driven arthritis, and assess the intensity of immune activation. It is especially useful when symptoms are nonspecific or early, when imaging may still be normal, and when a single marker alone would be misleading. Like most immune and inflammation tests, results are most powerful when interpreted in context rather than in isolation.