PRTN3 and rheumatoid arthritis: The primary objective of this work was to study whether, in a cohort of 184 patients with ACPA-positive RA fulfilling the 2010 ACR/EULAR criteria, a particular HLA-DR background or original clinical patterns, were associated with antibodies to the epitopes from the 5 major hFib-cit peptides α36–50cit, α171–185cit, α501–515cit, α621–635cit, and β60–74cit.