Serum Antibody Titres Against Porphyromonas gingivalis Fim A in Patients with Periodontitis with and Without Diabetes Mellitus Type 2

Periodontitis and type 2 diabetes mellitus are interconnected in a bidirectional relationship, yet the underlying mechanisms remain poorly understood. <i>Porphyromonas gingivalis</i> (<i>P. gingivalis</i>), a key periodontal pathogen, has been implicated in both conditions. This study investigates the association between antibody responses to <i>P. gingivalis</i> and the coexistence of periodontitis and diabetes, aiming to explore its potential as a biomarker for early screening. The developed enzyme linked immunosorbent assay (ELISA) was used to analyse in a pilot study the serum of subjects with periodontitis (<i>n</i> = 26), subjects with periodontitis and type 2 diabetes mellitus (<i>n</i> = 15), and healthy individuals (<i>n</i> = 13) for immunoglobulin (Ig)G- and IgM-antibody titres against FimA. A statistically significant difference (<i>p</i> < 0.001) between the IgG titres of the three study groups was observed. Patients with periodontitis and type 2 diabetes mellitus showed the highest IgG titres and thus the highest level of IgG antibodies, followed by periodontitis patients and finally the orally healthy subjects. This study demonstrated the establishment of a reliable and reproducible ELISA for the detection of antibodies against FimA from <i>P. gingivalis</i> W83. In addition, the outcomes of this study can be used to develop a screening assay that can indicate existing periodontitis and type 2 diabetes mellitus based on IgG antibody titres against FimA from <i>P. gingivalis</i>.