Anti-cardiolipin and Anti-b2-Glycoprotein I in Periodontitis

Objectives: Anti-phospholipid antibodies, including anti-cardiolipin (a-CL), anti-b2-glycoprotein I (a- b2GPI), and lupus anticoagulant antibodies, are characteristic of the Antiphospholipid Syndrome (APS), which is present in about 30% of patients with SLE. The clinical sequellae of APS, including thrombotic events such as stroke, myocardial infarction, and adverse pregnancy outcomes such as spontaneous abortions and prematurity, are remarkably similar to systemic conditions associated with periodontitis. Furthermore, some microbial pathogens are thought to be able to induce cross-reactive a- b2GPI . We therefore measured levels of anti-CL and a- b2GPI in sera from patients characterized as to their periodontal status. Methods: Sera were collected from a total of 335 subjects with no attachment loss (NP), gingival recession (GR), chronic periodontitis (CP), or aggressive periodontitis (LAgP and GAgP). Commercially available ELISA assays for a-CL and a- b2GPI were employed. Results: There were no differences in levels of a-CL between the diagnostic groups. However, CP and GR patients had significantly elevated mean levels of a- b2GPI (10.8+2.8 and 11.9+2.8 U/ml respectively) compared to NP (7.4+3.0), LAgP (8.2+3.2) and GAgP (7.3+3.1) patients. There was a significantly greater proportion of subjects with clinically elevated levels of this antibody (>11U/ml) in patients with CP and GR than in the other groups. A cross-reactive hexapeptide of b2GPI (TLRVYK) reported to be found in antigens from a variety of microbial pathogens was found by a BLAST database search to be present in the arg-gingipain of P. gingivalis. Absorption of sera with high titers of a- b2GPI with P. gingivalis W83 and 33277 resulted in absorption of a- b2GPI. Conclusions: The pathologic autoantibody a- b2GPI is present in patients with periodontal attachment loss, and P. gingivalis may have an cross-reactive epitope with b2GPI. This may in part explain the systemic pathology observed in patients with periodontitis. Supported by DE13102 from NIH/NIDCR.