RHEUMATOID FACTOR (RA)
1 SST/2.0 mL serum. After 30 minutes of clotting, promptly centrifuge and refrigerate.
Refrigerate: 8 days
Rheumatoid factor is essentially an IgM antibody that is directed toward IgG. Although it is a non-specific marker, it is associated with autoimmunity and rheumatoid arthritis. IgG antibodies may be altered to be recognized as “foreign”, resulting in an autoimmunity.