Relatives Without Rheumatoid Arthritis Show Reactivity to Anti–Citrullinated Protein/Peptide Antibodies That Are Associated With Arthritis‐Related Traits: Studies of the Etiology of Rheumatoid Arthritis

Abstract

RA-free first-degree relatives (even those negative for RF and anti-CCP-2) demonstrate reactivity to multiple ACPAs, and the presence of an increasing number of ACPAs may be associated with signs of joint inflammation. Prospective evaluation of the relationship between these findings and the progression of classifiable RA is warranted.