It can be quite difficult to diagnose rheumatoid arthritis (RA).
People can have different symptoms and yet still be classified as having RA. So, what's the difference between Seronegative and Seropositive RA?
In this video, I explain these classifications.
A RA diagnosis is made from a combination of clinical symptoms and findings, supported by various investigations.
Useful investigations include the following blood tests: rheumatoid factor (RF), anti-cyclic citrullinated peptide antibodies (anti-CCP) and the inflammatory markers (ESR and CRP). However, up to 30% of patients have completely normal blood tests.
RF testing is actually testing for a group of non-specific antibodies. While they can be found in up to 70% of patients diagnosed with RA, they can also occur in healthy people who will never get rheumatoid arthritis. RF can be elevated in many diseases such as hepatitis, chronic infection or other inflammatory diseases.
Anti-CCP antibodies, also known as ACPA are much more specific for RA. This means that a positive anti-CCP result will usually be highly suggestive that RA is the diagnosis.
A negative anti-CCP result does not however rule out the disease as these antibodies are not found in all patients.
A positive anti-CCP result tends to be suggestive of a potentially more serious and destructive disease (if not controlled by appropriate treatment).
Seropositive RA refers to the presence of RF and/or anti-CCP antibodies in a person diagnosed with RA.
Seronegative RA refers to the situation where both antibodies are not elevated.
It's useful for you to understand this distinction. Sometimes, it may influence how certain your rheumatology team is with the diagnosis, and sometimes it may affect the treatment plan.