The relationship between gingivitis and the serum antibodies to the microbiota associated with periodontal disease in children with Down's syndrome.

Gingival inflammation in Down's syndrome children (DS) develops earlier and is more rapid and extensive than in non-DS children. Abnormalities in host response to the oral flora have been proposed as etiological factors of this gingival inflammation. However, the relationship between gingivitis and the host response to oral microorganisms in DS by age has not been determined. The objective of this study was to clarify this relationship. Sera were obtained from 75 DS subjects (aged 2 to 18 years) and their gingival health assessed using a modified PMA Index (M-PMA). Antibody titers to Porphyromonas gingivalis (Pg), Prevotella intermedia (Pi), Treponema denticola (Td), Fusobacterium nucleatum (Fn), Selenomonas sputigena (Sel), Actinobacillus actinomycetemcomitans (Aa), and Streptococcus mitis (Mi) were determined using the micro-ELISA. DS subjects under 4 years old were found to have significantly more gingival inflammation than did normal children the same age. A significant positive correlation (r = 0.548, P < 0.0001) existed in the relationship between M-PMA score and plaque score for subjects in the G1 age group (deciduous dentition). At G1, the average antibody titers to Aa, Mi, and Fn exceeded those of the normal adult reference serum pool. In addition, IgG antibody titers to Pg, Aa, Fn, Sel, and Mi correlated significantly with the M-PMA scores in the G1 age group. There was a correlation between age (2 to 18 years) and these antibody titers. IgG antibody titers to Pg, Aa, Sel, and Mi increased significantly with increasing M-PMA score. Furthermore, the IgG antibody titers to Pg were higher (P < 0.05) in the most extensive disease group compared to the DS no-disease group. The IgG antibody titers to Pg at G3 (early puberty) were significantly higher when compared to G1 (preschool children). The IgM antibody titers to Aa at G3 were higher (P < 0.05) when compared to G1. This study suggests that colonization by Aa and Fn are closely associated with the onset of gingival inflammation in DS patients under 5 years old. Colonization by Pg, Aa, Sel, and Mi in DS appears to be associated with gingivitis at puberty.