<prompt> Which of the following statements about Rheumatoid Factor is true -It is an IgM antibody directed against IgGIt is an IgG antibody directed against IgMIt is more specific than Anti-CCP antibodiesIt is positive in all cases of Juvenile Rheumatoid Arthritis  <response>: Rheumatoid factor in Rheumatoid Arthritis is an IgM antibody directed against the Fc fragment of IgGAnti CCP antibodies are most specific blood test for rheumatoid arthritis specificity 95.Rheumatoid factor is positive in only 10 of patients with JRA. 