biostudies-literatureDe Vries CNIDCR NIH HHSEuropean Research Councile005111https://www.ebi.ac.uk/biostudies/studies/S-EPMC11792289biostudies-literatureUnknown11(1)<h4>Objective</h4>The antibody response against <i>Porphyromonas gingivalis</i> (<i>Pg</i>) is elevated in rheumatoid arthritis (RA), especially in patients with anti-citrullinated protein antibodies (ACPA). Here, we investigated whether antibodies against the <i>Pg</i> virulence factor arginine gingipain (Rgp) are associated with the RA-risk phase and development of arthritis.<h4>Methods</h4>At-risk individuals were included in a prospective study (Risk-RA) based on a positive anti-cyclic citrullinated peptide 2 (CCP2) antibody test, and having musculoskeletal complaints but no signs of arthritis. Study participants were followed for ≥3 years (arthritis-free, n=165) or until arthritis onset (progressors, n=95). Anti-Rgp IgG was measured in Risk-RA (260 baseline and 247 follow-up samples) RMD open&lt;i&gt;Porphyromonas gingivalis&lt;/i&gt; associates with the presence of anti-citrullinated protein antibodies, but not with the onset of arthritis: studies in an at-risk population.PMC11792289772209R01 DE022597De Vries CCirciumaru AKisten YHensvold APotempa BLundberg KMathsson-Alm LWesterlind HPotempa JDehara Mfalse&lt;i&gt;Porphyromonas gingivalis&lt;/i&gt; associates with the presence of anti-citrullinated protein antibodies, but not with the onset of arthritis: studies in an at-risk population.<h4>Objective</h4>The antibody response against <i>Porphyromonas gingivalis</i> (<i>Pg</i>) is elevated in rheumatoid arthritis (RA), especially in patients with anti-citrullinated protein antibodies (ACPA). Here, we investigated whether antibodies against the <i>Pg</i> virulence factor arginine gingipain (Rgp) are associated with the RA-risk phase and development of arthritis.<h4>Methods</h4>At-risk individuals were included in a prospective study (Risk-RA) based on a positive anti-cyclic citrullinated peptide 2 (CCP2) antibody test, and having musculoskeletal complaints but no signs of arthritis. Study participants were followed for ≥3 years (arthritis-free, n=165) or until arthritis onset (progressors, n=95). Anti-Rgp IgG was measured in Risk-RA (260 baseline and 247 follow-up samples) 2025-01-01T00:00:00Z2025 Jan2025-04-04T07:26:22.241Z2025-04-04T07:26:22.241ZS-EPMC117922893989020610.1136/rmdopen-2024-005111