In the CP group, sera reactivity by ELISA was significantly higher than in the G and H groups (Kruskal-Wallis p<0.001; Dunnet t3 p= 0.001 and Dunnet t3 p= 0.0001). There was no statistically significant difference between G and HP reactivity (Dunnett t3 p=0.617). Among individuals with chronic periodontitis, the IgG-anti-P. gingivalis serum levels were positively correlated with percentage of clinical attachment level =5mm (r s = + 0.375, p<0.05) and a negative correlation was found between IgG-anti-P. gingivalis levels and percentage of probing pocket depth 0-3mm (r s = - 0. 411, p< 0.05). The analysis of sera immunoreactivity profiles to sonicate antigen by Western blotting showed differences between the sera of CP, G and H group individuals. The serum from CP frequently reacted with high molecular weight (103 kDa, 86 kDa, 72 kDa, 60 kDa, 58 kDa, 52 kDa) protein fractions.
Conclusions:
Serum levels of IgG anti-P. gingivalis distinguished individuals with chronic periodontitis, gingivitis and healthy periodontium. There was a correlation between clinical parameters and serumIgG levels against P. gingivalis. There was a difference in the recognition profile of protein fractions among the studied groups and some bands were more specific.