Ageing effects on humoral immune responses in chronic periodontitis

Abstract

Periodontal disease is a dominant global bacterial infection that increases with ageing.

Aim: This report focuses on host adaptive immune responses in periodontitis. While experimental models and humans diagnosed with periodontitis demonstrate an antigenic specificity for particular oral bacteria, we have a limited understanding of (i) how ageing affects the adaptive immune responses to these bacteria that chronically colonize the oral cavity for decades prior to disease expression and (ii) how the magnitude and specificity of the response interface with pathogens that emerge within the bacterial ecology during exacerbations of disease.

Materials and methods: Serum antibody levels to a group of pathogenic and commensal oral bacteria were measured in a population of individuals from 21 to 74 years of age, stratified based on clinical status of the periodontium, smoking and sex.

Results: Clinical parameters were not significantly different within health, gingivitis or periodontitis groups related to age. Antibody to oral pathogens and commensals was similar in different age groups in each of the clinical categories, with no age correlation noted in the periodontitis patients.

Conclusions: The adaptive immune responses to oral bacteria that chronically colonize the oral cavity appear generally unaffected by age, but clearly are linked to the extent of disease.

Keywords: ageing; antibody; oral bacteria; periodontitis.

Figure 1

Clinical measures of periodontal disease (A) bleeding on probing (BOP); (B) mouth mean probing pocket depth (PPD); (C) Percentage (%) of sites with PPD ≥ 4 mm; and (D) Percentage (%) of sites with PPD ≥ 5 mm according to age stratification in years. The bars denote group means and the vertical brackets enclose 1 SD.

Figure 1

Clinical measures of periodontal disease (A) bleeding on probing (BOP); (B) mouth mean probing pocket depth (PPD); (C) Percentage (%) of sites with PPD ≥ 4 mm; and (D) Percentage (%) of sites with PPD ≥ 5 mm according to age stratification in years. The bars denote group means and the vertical brackets enclose 1 SD.

Figure 1

Clinical measures of periodontal disease (A) bleeding on probing (BOP); (B) mouth mean probing pocket depth (PPD); (C) Percentage (%) of sites with PPD ≥ 4 mm; and (D) Percentage (%) of sites with PPD ≥ 5 mm according to age stratification in years. The bars denote group means and the vertical brackets enclose 1 SD.

Figure 1

Clinical measures of periodontal disease (A) bleeding on probing (BOP); (B) mouth mean probing pocket depth (PPD); (C) Percentage (%) of sites with PPD ≥ 4 mm; and (D) Percentage (%) of sites with PPD ≥ 5 mm according to age stratification in years. The bars denote group means and the vertical brackets enclose 1 SD.

Figure 2

Serum IgG antibody responses to (A) periodontal pathogens (A. actinomycetemcomitans-Aa, P. gingivalis-Pg, T. denticola-Td, T. forsythia-Tf); (B) oral commensal bacteria (A. naeslundii-An, C. ochracea-Co, P. loeschii-Pl, S. sanguinis-Ssa, V. parvula-Vp); and (C) sum of antibody levels to the group of pathogens or group of commensal bacteria. The bars denote group means and the vertical brackets enclose 1 SD. The asterisk (*) denotes significantly different than other disease categories for the same age category at least at p<0.05. The hashtag (#) denotes significantly different from levels in healthy subjects in the same age category at least at p<0.05.

Figure 2

Serum IgG antibody responses to (A) periodontal pathogens (A. actinomycetemcomitans-Aa, P. gingivalis-Pg, T. denticola-Td, T. forsythia-Tf); (B) oral commensal bacteria (A. naeslundii-An, C. ochracea-Co, P. loeschii-Pl, S. sanguinis-Ssa, V. parvula-Vp); and (C) sum of antibody levels to the group of pathogens or group of commensal bacteria. The bars denote group means and the vertical brackets enclose 1 SD. The asterisk (*) denotes significantly different than other disease categories for the same age category at least at p<0.05. The hashtag (#) denotes significantly different from levels in healthy subjects in the same age category at least at p<0.05.

Figure 2

Serum IgG antibody responses to (A) periodontal pathogens (A. actinomycetemcomitans-Aa, P. gingivalis-Pg, T. denticola-Td, T. forsythia-Tf); (B) oral commensal bacteria (A. naeslundii-An, C. ochracea-Co, P. loeschii-Pl, S. sanguinis-Ssa, V. parvula-Vp); and (C) sum of antibody levels to the group of pathogens or group of commensal bacteria. The bars denote group means and the vertical brackets enclose 1 SD. The asterisk (*) denotes significantly different than other disease categories for the same age category at least at p<0.05. The hashtag (#) denotes significantly different from levels in healthy subjects in the same age category at least at p<0.05.

Figure 3

Heat map of correlation of serum antibody levels in periodontitis patients stratified by age group and categorized by severity of periodontitis. The red circles highlight areas of the heat maps depicting different patterns of antibody correlations with clinical features in the age groups and disease severity.

Figure 4

Distribution of total bacterial and individual oral pathogens in subgingival plaque samples from diseased (A) and healthy sites (B) in periodontitis patients categorized into different age groups. The bars denote group means and the vertical brackets enclose 1 SD. The asterisk (*) denotes significantly different than other age categories at least at p<0.05.

Figure 4

Distribution of total bacterial and individual oral pathogens in subgingival plaque samples from diseased (A) and healthy sites (B) in periodontitis patients categorized into different age groups. The bars denote group means and the vertical brackets enclose 1 SD. The asterisk (*) denotes significantly different than other age categories at least at p<0.05.

Figure 5

(A) Serum antibody levels based on sex and stratified into age categories. (B) Serum antibody levels in smokers and nonsmokers stratified into age groups. The bars denote group means and the vertical brackets enclose 1 SD. The asterisk (*) denotes significantly different than other sex within an age category at least at p<0.05.

Figure 5

(A) Serum antibody levels based on sex and stratified into age categories. (B) Serum antibody levels in smokers and nonsmokers stratified into age groups. The bars denote group means and the vertical brackets enclose 1 SD. The asterisk (*) denotes significantly different than other sex within an age category at least at p<0.05.