Context: Rheumatoid arthritis (RA) has a heterogeneous course, spanning from mild forms tending to
remission and reacting well to treatment, to aggressive forms resistant to classical therapeutic measures.
Reliable predictive parameters of the disease course in RA are needed. Raised levels of Rheumatoid
Factors (RFs) are associated with RA and that this RF is found in IgM, IgA and IgG classes
(isotypes).
