JUP and rheumatoid arthritis: Albeit our data cannot support that the presence of Porphyromonas gingivalis DNA represents a surrogate marker for the occurrence of ACPA [31], certainly the presence of Pg DNA in UPIA and its presence in the synovial tissue of RA patients, suggests that the bacterium has a role in the pathogenesis of RA, which can still be maintained long after the initial disruption of the immunologic tolerance.