β2-Glycoprotein I-Dependent Anti-Cardiolipin Antibodies Associated With Periodontitis in Patients With Systemic Lupus Erythematosus

Background: It was reported that patients with systemic lupus erythematosus (SLE) exhibited increased levels of anticardiolipin (anti-CL) antibodies, a class of antiphospholipid antibodies associated with thrombosis. beta 2-glycoprotein I (beta 2GPI) has been considered as the actual target antigen for anti-CL antibodies. This study investigates the association of periodontal infection with anti-CL antibodies in patients with SLE. Methods: Fifty-three SLE female patients and 56 healthy female volunteers were recruited in this case-control study. All participants received periodontal examinations. The presence of Porphyromonas gingivalis and Treponema denticola in saliva and plaque samples was detected by polymerase chain reaction. Levels of serum anti-CL and anti-beta 2GPI antibodies were examined using enzyme-linked immunosorbent assay. Results: Patients with SLE exhibited more periodontal attachment loss and increased titers of serum anti-CL and anti-beta 2GPI antibodies compared with healthy controls. Patients with active SLE who harbored P. gingivalis or P. gingivalis together with T. denticola intraorally exhibited significantly higher anti-CL and anti-beta 2GPI antibodies than those without these bacteria. Anti-CL and anti-beta 2GPI antibody levels correlated positively with clinical attachment level. Furthermore, increased anti-beta 2GPI antibody levels were significantly associated with C-reactive protein and erythrocyte sedimentation rate. Conclusions: Elevated anti-CL and anti-beta 2GPI antibody levels were associated with periodontopathic bacteria and periodontal breakdown in patients with SLE. Periodontitis might be a modifiable risk factor for SLE.