Nonspecific and specific immune responses in a child with Down's syndrome and her sibling. A case report

Periodontal diseases in Down syndrome during childhood: a scoping review

BACKGROUND

Down syndrome (DS) is a genetic condition that involves the deregulation of immune function and is characterized by a proinflammatory phenotype leading to an impaired response to infections. Periodontitis is a highly prevalent chronic inflammatory disease. It has been shown that adults and teenagers with DS are more susceptible to this disease, but a similar correlation in DS children remains elusive. This systematic scoping review aims to address this knowledge gap by examining periodontitis in DS children, with a secondary objective of elucidating the underlying mechanisms involved.

METHODS

Our primary search was conducted via the PubMed/MEDLINE database and Google Scholar, covering the period from 1951-July 1st, 2024. Primary studies written in English or French were included. The excluded articles were reviews, in vitro or animal studies, studies on teenagers or adults, and studies involving patients with disabilities other than DS. The quality of evidence was assessed via the Newcastle‒Ottawa scale for observational studies and a published tool for evaluating the quality of case reports and case series.

RESULTS

The initial electronic database search yielded a total of 2431 articles. 58 full-text articles, comprising seven cross-sectional studies, 36 case‒control studies, seven cohort studies, and eight case reports and case series, were included in the review. Compared with healthy children or children with disabilities, DS children appear to have more severe periodontal inflammation. However, the evidence is inconclusive regarding the presence of bone loss, with studies divided on this issue. Local risk and etiopathogenetic factors do not seem to play a significant role in increased inflammation. Instead, this difference could be attributed to the general proinflammatory phenotype of children with DS.

CONCLUSIONS

DS children seem to have higher periodontal inflammation than other children, but no periodontal bone loss. Investigating periodontal inflammation in DS children could provide valuable insights into the deregulation of immune function in these patients.

Aggressive forms of periodontitis secondary to systemic disorders

A number of systemic disorders increase a patient's susceptibility to destructive periodontitis and have impacts on periodontal disease progression and severity. The underlying factors are usually genetic and are mainly related to alterations in the immune response and in certain endocrine functions, leading to various syndromes in which periodontitis and/or early tooth loss are secondary manifestations. Neutrophils are important immune defense cells that play a significant role in controlling the spread of microbial plaque infections in the dentogingival region. This review focuses on a selected group of systemic disorders that are associated with alterations in either neutrophil counts (quantitative disorders) or function (qualitative disorders), and defects in the mineralization of bone and dental tissues. In most of these diseases controlling the periodontal disease progression is very challenging. Proper diagnosis is a prerequisite for proper management of the periodontal problem. Future advances in research, including gene targeting and the resolution of enzyme deficiencies, may bring about remedies of the underlying systemic disorders and may significantly improve the outcome of periodontal treatment in these patients.

Oxidative burst intensity of peripheral phagocytic cells and periodontitis in Down syndrome

BACKGROUND

This study investigated the oxidative burst function of peripheral phagocytic cells (granulocytes and monocytes) and assessed the relation between oxidative burst and periodontal status in adult individuals with Down syndrome (DS) vs. other groups.

METHODS

Of 55 DS individuals (18-56 years old), 74 individuals with mental retardation (MR) and 88 medically healthy controls (HC) participated in the study. The MR and HC groups were age, race and gender matched with the DS group. Gingival index, plaque index, probing depth, attachment level and bleeding on probing were recorded for each subject. Whole blood was collected for granulocyte/monocyte oxidative burst tests. Oxidative burst was determined by flow cytometry in terms of percentage of cells actively involved in oxidative burst, and oxidative intensity (magnitude of ROIs per cell).

RESULTS

The basal oxidative burst intensity of DS granulocytes was higher than that of HC and MR granulocytes (p = 0.05). The Escherichia coli stimulated oxidative burst intensity of DS monocytes was higher than that of HC and MR monocytes (p = 0.05). Regression analysis controlling for age, sex, race and plaque levels showed a significant association between monocyte oxidative burst intensity and loss of periodontal attachment in DS subjects (p < 0.01). Regression analysis also showed a significant association between granulocyte oxidative burst intensity and bleeding on probing in all subjects (p < 0.05).

CONCLUSIONS

Oxidative burst activity of peripheral monocytes and granulocytes is elevated in DS affected individuals and may contribute to periodontal tissue inflammation and loss of periodontal attachment in this susceptible group.

Phagocytic cell activity and periodontitis in Down syndrome

BACKGROUND

This study investigated the phagocytic function of peripheral granulocytes and monocytes from adult individuals with Down syndrome (DS) and assessed the relation between phagocytic function and periodontal status.

METHODS

Fifty-five DS individuals (18-56 years old), 74 mentally retarded individuals, and 88 medically healthy controls (HC) participated in the study. Gingival inflammation index, plaque index, probing depth, periodontal attachment level (AL), and bleeding on probing were taken for each subject. Whole blood was collected for granulocyte/monocyte phagocytosis tests. Phagocytic function was determined by flow cytometry in terms of percentage of cells actively involved in phagocytosis, and phagocytic intensity (magnitude of the bacterial staining per cell).

RESULTS

Phagocytic intensity of both granulocytes and monocytes was comparable in HC and DS subjects. While AL was directly related to phagocytic intensity of both granulocytes (r = 0.14, P = 0.03) and monocytes (r = 0.2, P = 0.003) in all subjects, this relationship was stronger in DS than in other subjects, even after controlling for known risk factors for periodontitis (P < 0.05). Monocyte phagocytic intensity was the only necessary predictor of AL (P = 0.003), indicating a similar relationship between AL and phagocytic activity in either cell type.

CONCLUSIONS

While granulocyte and monocyte phagocytic intensities are similar in Down and non-DS individuals, phagocytic intensity was associated with more AL in DS than non-DS individuals.

A Comparison of the Gingival Health of Children with Down Syndrome to Healthy Children Residing in an Institution

The purpose of this study was to compare the onset and severity of gingivitis in children with Down syndrome, when compared to a healthy control group of children. The subjects included 41 children with Down syndrome ages two to 14 years (mean age: 7.6 years) and 112 age-matched healthy controls. We assessed the gingival health of all subjects using the gingival inflammation (M-PMA) index and periodontal probing depth (PD). Children were divided into three age categories: <5 years (AI), 5 to <10 years (AII), and 10 to <17 years (AIII). Supragingival plaque was measured using the Oral Hygiene Index (OHI) and the subjects were screened with the BANA test (Perioscan-Oral-B). Measurement of the M-PMA index in the healthy children showed an age-related increase (F = 10.369, p < 0.001), and the M-PMA index at the younger age group <5 year (AI) was significantly lower than that for the other two age groups All or AIII (p < 0.005, p < 0.001). In contrast, the M-PMA index values at AI and AIII in the subjects with Down syndrome were significantly higher than those for healthy children (p < 0.001, p < 0.001). Both groups had an age-related increase in PD (F = 3.388, p < 0.05 & F = 10.806, p < 0.001), and PD at AIII was significantly higher than that at AI in both groups (p < 0.01, p < 0.001). The children with Down syndrome showed an age-related increase in the BANA test score (F = 3.452, p < 0.05), and the BANA test score at AIII was significantly higher than that at AI (p < 0.02). The BANA test score in the healthy children was not age-related but was significantly higher than that in the children with Down syndrome (p < 0.02, p < 0.05).

Evaluation of Surgical and Non-Surgical Periodontal Therapies, and Immunological Status, of Young Down's Syndrome Patients

BACKGROUND

Individuals with Down's syndrome (DS) differ in their oral condition compared with the healthy population. Periodontal disease in persons with DS under the age of 30 years is very high. Immune deficiencies are also present. For dental practitioners it is difficult to decide on a particular course of treatment. In this study, patients with DS were selected in order to 1) evaluate the effectiveness of surgical and non-surgical periodontal therapies and 2) assess their immunological status.

METHODS

The population consisted of 14 DS patients (14 to 30 years old). Surgical and non-surgical periodontal therapies were compared in a split-mouth design. Clinical measurements of plaque index (PI), gingival index (GI), probing depth (PD), and clinical attachment levels (CAL) were taken at baseline, posttreatment, 6 months, and 1 year. Immunomodulatory activity of neutrophils was analyzed in vitro by chemotaxis (Boyden migration chamber), phagocytic activity, and production of super-oxide anion (NBT reduction) tests and compared between DS patients and healthy controls.

RESULTS

Both surgical and non-surgical therapies showed a significant improvement in all the clinical parameters compared to baseline. There were no differences between surgical and nonsurgical therapy in PI or GI. There was a significant PD reduction with the non-surgical therapy at 1 to 3 mm PD. However in PD >3 mm the surgical therapy, although not statistically significant, showed better results. Neutrophil chemotaxis, phagocytic activity, and production of super-oxide anion were significantly decreased in the DS patients.

CONCLUSIONS

After a year, both surgical and non-surgical therapies have similar periodontal clinical improvement in DS patients. There is partial impairment of immunological functions in DS individuals which does not seem to affect the clinical response to therapy.

Derangement of non-specific immunity in Down syndrome subjects: low leukocyte chemiluminescence activity after phagocytic activation

Metabolic activation of peripheral blood leukocytes (chemiluminescence) from 27 children with Down syndrome (DS) and 23 age and sex-matched control children after phagocytic stimulation by opsonized zymosan particles was investigated through a chemiluminescence assay. Using autologous plasma or serum as opsonizing media, phagocytic activity of circulating leukocytes was significantly decreased in DS subjects. A further decrease of phagocytic activity was found in neutrophils from DS children, when normal heterologous plasma or sera were used. On the other hand, sera or plasma from DS subjects significantly increased phagocytic activation of leukocytes from normal donors. In DS subjects opsonizing agents such as serum immunoglobulins and complement fractions were in the normal ranges of concentration. Thus, the impaired chemiluminescence of neutrophils was mainly due to a metabolic impairment at the cellular level. A decreased production of radicals derived from the oxygen metabolism in neutrophils may be an important step of immune derangement leading to the increased incidence of infectious diseases frequently associated with DS.

Enhancement of lipopolysaccharide-stimulated cyclooxygenase-2 mRNA expression and prostaglandin E2 production in gingival fibroblasts from individuals with Down syndrome

It is well known that Down syndrome (DS) is a premature ageing syndrome. Periodontal disease in individuals with DS develops rapidly and extensively in a relatively younger age bracket compared with that in healthy controls. The mechanisms involved in the periodontal inflammatory processes in DS patients are not fully understood. In the present study, the non-inflamed gingival fibroblasts isolated from seven patients with DS (DGF) and seven healthy controls (NDGF) were stimulated with lipopolysaccharide (LPS) derived from Actinobacillus actinomycetemcomitans (A. a.). We measured the level of prostaglandin E2 (PGE2) production by DGF and NDGF by radioimmunoassay, and also measured the mRNA expression of cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) by using the real-time PCR method. We found the higher levels of LPS-stimulated COX-2 mRNA expression and PGE2 production in DGF when compared with those in NDGF. This study may indicate that overexpression of LPS-stimulated COX-2 induced a greater ability of DGF to produce PGE2, and that these phenomena may be responsible for the severer periodontal disease in DS patients.

Absence of a specific subgingival microflora in adults with Down's syndrome

BACKGROUND

Periodontal disease in Down's syndrome (DS) is generally characterized by a high degree of bone loss. Bone loss of 5 mm or more is observed in 70% of these subjects. Among DS subjects, considerable differences in disease progression occur. So far, no studies have been conducted in which specific properties of the subgingival microflora have been related to the condition observed.

AIMS

To investigate (1) the subgingival microflora in DS subjects and other mentally retarded (control) individuals which were matched to the utmost and (2) to investigate the subgingival microflora of a "low-risk" and a " high-risk" group formed in DS subjects.

MATERIAL AND METHODS

17 DS subjects and 17 control subjects were matched with respect to age, plaque level and bleeding on probing. In addition, the DS group was divided in a "low-risk" group (0-2 teeth lost due to periodontal disease n=6) and a "high-risk"group (6-13 teeth lost due to periodontal disease n=11). Prevalence and proportions of the putative periodontal pathogens Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Bacteroides forsythus, Peptostreptococcus micros, Fusobacterium nucleatum and Campylobacter rectus in the subgingival plaque were determined using anaerobic culture techniques. No differences in the prevalence of distinct suspected periodontopathic bacteria and bacterial subgingival composition between the DS group and the control group could be established. Also no differences in the prevalence of the seven investigated microbial species between the "low-risk" and the "high-risk" group were observed.

CONCLUSIONS

Because of the lack of differences in microflora between the DS group and the control group, a specific effect of the microbiological composition in the periodontal status of subjects with DS can be excluded in this population. Host factors constitute the more likely explanation of the differences observed in DS.

A survey of oral health in a population of adults with developmental disabilities: comparison with a national oral health survey of the general population

During 1991, an oral health assessment of 101 adults with developmental disabilities aged from 21 to 53 years was undertaken as part of a broader health survey which also included medical, psychological and nutritional assessments. The study group consisted of a random sample of adults chosen from the developmentally disabled population known to be living in the lower North Shore area of Sydney. This paper describes the results of the oral health assessment and compares them with an oral health survey of the Australian population done in 1987/88. Forty-six per cent of the study group were males (mean age 33.5 years) and 54 per cent were females (mean age 33.0 years). Compared with similar age subgroups in the Australian population, the following factors were more frequently reported in the developmentally disabled group: a dental visit in the last 12 months (65 per cent vs 50 per cent; Odds Ratio (OR) 1.9:95 per cent Confidence Interval (CI): 1.3-2.8); use of public rather than private dental services (42 per cent vs 6 per cent; OR 11.3:95% CI 7.5-16.9); oral mucosal pathology requiring treatment (15 per cent vs 2 per cent; OR 8.5:95% CI 5.2-13.8); severe periodontal disease (16 per cent vs 3 per cent; OR 6.9:95% CI 4.2-11.4); and moderate to severe malocclusion (26 per cent vs 11 per cent; OR 2.1:95% CI 1.3-3.5). Fifty-eight per cent of subjects felt they needed no dental treatment but on examination of the oral mucosa, periodontal tissues and teeth, over 90 per cent were found to require some sort of dental treatment.

Serum antibody response to Actinobacillus actinomycetemcomitans in Down's syndrome

Persons with Down's syndrome (DS) are susceptible to severe and precocious periodontal disease. Several organisms have been implicated in the etiology of periodontal disease, including Actinobacillus actinomycetemcomitans (Aa). It is unknown whether circulating antibodies correlate with the severity of periodontal disease in DS. This study determined the circulating antibody titers to Aa in sera of DS and normal patients. Eleven DS patients with periodontal disease (pocket depth > 4 mm), five DS patients with gingivitis (inflammation and pocket depth < or = 3 mm), and 10 non-DS healthy subjects had blood drawn and analyzed for antibody response to Aa. Conventional enzyme-linked immunosorbent assay (ELISA) with goat anti-human IgG was performed for Aa-reactive serum diluted 1:200 to 1:12,800. Geometric mean titer was calculated, and significant differences were noted between the control group and the DS groups (p = 0.05), with the DS periodontal group having the highest response, followed by the DS gingivitis and normal controls, respectively. The DS groups were not significantly different. DS patients may exhibit a higher Aa antibody response, due to the presence of the organism, previous exposure, or in proportion to the extent of their periodontal condition.

Nonspecific immunity in Down syndrome: a study of chemotaxis, phagocytosis, oxidative metabolism, and cell surface marker expression of polymorphonuclear cells

We have investigated several aspects of nonspecific immunity in Down syndrome (DS), utilizing peripheral polymorphonuclear leukocytes (PMNL), obtained from 12 children aged 8-16, diagnosed as trisomy 21, and their healthy matched controls. We used the under agarose method for chemotaxis assays, and flow cytometry for the determination of phagocytosis of monodispersed fluorescent beads, metabolic burst activity, and neutrophil surface marker expression on these cells. Our results indicate that a chemotactic defect exists in PMNL of DS children. However, no statistically significant differences were found between PMNL from DS children and those from controls in phagocytosis, oxidative burst, and expression of the markers CD11a, CD11b, CD16, and CD 18. Furthermore, no overexpression of CD11a and CD18 was present as a consequence of gene overdosage in PMNL from DS children. On the other hand, 3 different neutrophil subpopulations could be observed according to the CD16 staining pattern in DS children and controls; this might be a consequence of genetic variation or may represent different states of activation of these cells. Other factors such as T-cell involvement, and the role of cytokines, cyclic nucleotides, and zinc serum levels in DS patients should be further investigated in order to define the causes of the immunological derangement present in this condition.