Avaliação dos níveis séricos de anticorpos IgG e subclasses e IgA, reativos a Porphyromonas gingivalis em indivíduos com periodontites crônica e agressiva

by Trindade, Soraya Castro

Periodontitis is an inflammatory oral disease caused by multifactorial intrinsic and extrinsic agents including Gram-negative bacteria, like Porphyromonas gingivalis. This study was undertaken to evaluate immunoglobulin A, Immunoglobulin G and immunoglobulin G isotype serum antibodies against Porphyromonas gingivalis ATCC33277. This study included 89 patients divided in four groups: 29 chronic periodontitis (CP), 12 aggressive periodontitis (AP), 22 gingivitis or mild periodontitis (GP), and 26 healthy controls (HC). Humoral response was assayed by ELISA to verify serum levels of IgG, IgG1, IgG2, IgG3, IgG4 and IgA reacting to sonicated P. gingivalis ATCC 33277 crude extract and fraction IV obtained by chromatography. Serum levels of IgA, IgG (p<0,01), IgG2, IgG3 and IgG4 to the fourth eluate was higher in CP group compared to healthy control. CP group had higher levels of IgG and IgG4 to both antigens than GP group and higher levels of IgG and IgG4 to sonicate than AP group. There were statistically significant differences in serum levels of IgG to both antigens (p<0,01), IgG2 to fraction IV (p<0,01), IgG3 to fraction IV (p<0,05) and IgG4 to both antigens (p<0,05) between AP and HC groups. IgG1 titers to sonicate were significantly elevated (p<0,05) in GP compared to AP group. The findings suggest that the ELISA method to detect IgG and IgG4 to both antigens and IgG3 to fraction IV allow one to discriminate the groups, but IgG4 to fraction I was the best for discriminating among groups. Antibody production in the aggressive periodontitis group was not regular with respect to the isotypes analyzed