Dr. Alok Kalyani

Rheumatoid Factor (RF) is an autoantibody—a type of protein produced by immune system—that can attack your body’s own tissues instead of foreign antigens like bacteria and viruses.

Even if your rheumatoid factor (RF) is negative,You can have Rheumatoid Arthritis . This condition is known as seronegative rheumatoid arthritis.

Seronegative vs. Seropositive RA

• Seropositive RA: RF and/or anti-CCP (anti-cyclic citrullinated peptide) antibodies are positive.
• Seronegative RA: RF and anti-CCP antibodies are negative, but clinical symptoms and imaging still support a diagnosis of Rheumatoid Arthritis

Anti-CCP is More Specific

If RF is negative, a positive anti-CCP test may still confirm RA. If both are negative, the diagnosis may still be made based on symptoms and imaging.