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Objective: Down's syndrome (DS) individuals suffer from an increased susceptibility to infections. Here, we assessed age-related changes in the salivary-specific humoral immunity of DS subjects., Design: Parotid and whole saliva were collected from a young group of DS (YDS, n=30, 23.3+/-4 years), an older group of DS individuals (ODS, n=10, 51.9+/-8 years) and compared to two age-matched groups of healthy volunteers--a young group (YC, n=29, 22.8+/-5 years) and an older group (OC, n=10, 48.4+/-9 years). The levels of total IgA, and specific antibodies to three common oral pathogens (Porphyromonas gingivalis, Actinobacillus (Aggregatibacter) actinomycetemcomitans and Streptococcus mutans) were analysed., Results: The limited increases in IgA concentrations could not compensate the dramatic reduction in the salivary flow rate observed in DS individuals. Therefore, the median secretion rates of the specific antibodies in whole and parotid saliva were 70-77% and 34-60% (respectively) lower in YDS individuals as compared to YC and farther 77-100% and 75-88% (respectively) lower in ODS compared to YDS. In contrast, the antibody secretion rates were similar for parotid saliva, or even increased for whole saliva of OC, compared with YC. Consequently, a dramatic cumulative extreme reduction (>92%) in the bacterial specific salivary antibodies differentiated the adult DS individuals from to their age-matched controls., Conclusions: Our results indicate a severe immunodeficiency in the secretion rate of the specific salivary IgA response of in DS individuals which intensifies with age.

Antimicrobial peptides play an important role in the innate immune response. Deficiency in salivary LL-37 antimicrobial peptide has been implicated in periodontitis in patients with morbus Kostman syndrome. Down syndrome is associated with periodontitis, diminished salivary flow, and salivary immunoglobulin deficiency. In the present study, levels of LL-37 and its hCAP18 precursor were measured in saliva samples from young individuals with Down syndrome and compared with levels in those from age-matched healthy controls. LL-37 and human cathelicidin antimicrobial protein (hCAP18) were detected in whole but not in parotid saliva. hCAP18 was more abundant than LL-37. The concentrations of salivary hCAP18 and LL-37 were found to be higher in individuals with Down syndrome than in healthy controls, but their secretion rates were similar. We concluded that, while the adaptive immunity of individuals with Down syndrome is impaired at the oral mucosa, the secretion rate of the LL-37 component of the innate immune system is normal.

Background: Periodontal disease in Down's syndrome (DS) individuals develops earlier and is more rapid and extensive than in age-matched normal individuals. The present study evaluated a group of DS patients, who had been participating in a 10-year preventive dental programme, for the impact of the programme on their periodontal status., Methods: Thirty DS patients (mean age 23.3 +/- 4 years) were compared with 28 age-matched healthy controls (mean age 22.8 +/- 5 years). The hygiene level, gingival condition and periodontal status (periodontal probing depth, clinical attachment level and radiographic alveolar bone loss) were determined., Results: In spite of similar oral hygiene and gingival measures, DS patients, as opposed to the control ones, had a severe periodontal disease. The prevalence, extent and severity of periodontitis in the DS group were significantly greater than in the control group. The teeth most commonly and severely affected were the lower central incisors and the upper first molars. DS patients lost significantly more teeth due to periodontitis., Conclusions: The clinical and radiographic picture found in the present DS group is characteristic of localized aggressive periodontitis. Within the limitations of this study, it seems that the preventive dental programme had no effect on periodontal destruction progression of localized aggressive periodontitis in DS individuals and that impaired oral hygiene plays a relatively minor role in the pathogenesis of this disease. Future controlled studies are needed to assess the effectiveness of different preventive dental programmes in preventing the progression of periodontitis in DS patients.

Background: The purpose of the present study was to evaluate the possible correlation between recurrent respiratory infections (RRIs), gingival health and the secretion rates of salivary immunoglobulins (Igs) in institutionalized (I) and non-institutionalized (NI) individuals with Down's syndrome (DS)., Methods: Stimulated parotid saliva was collected from nine I and 14 NI subjects with DS. Salivary flow rate, secretion rates of total salivary IgM, IgG and IgA, and the incidence of RRIs were determined. Gingival health was recorded by using the plaque index, the gingival index and the percentage of bleeding surfaces (BS)., Results: The mean salivary flow rate and parotid Ig secretion rates in the I group were 25% of those of the NI group. The prevalence of RRIs in the I group was more than twice that in the NI group. Oral hygiene and gingival health were significantly better in the NI group., Conclusions: The lower parotid Ig secretion rates in I individuals with DS might be a possible factor involved in their susceptibility to recurrent infections compared to NI subjects with DS.

The purpose of the present investigation was to assess the correlation between recurrent respiratory infections and the levels of salivary Ig in a group of young Down's syndrome (DS) individuals. Twenty-three DS and 10 age- and sex-matched healthy individuals were included. DS individuals who had experienced three or more upper respiratory tract infections (n = 10) in the previous 12 months were compared to DS individuals who had not experienced recurrent respiratory infections (n = 13) and to healthy controls (n = 10). A statistically significant reduction in the Ig salivary secretion rate was recorded in the subgroup with recurrent respiratory infections. No significant differences were seen between the subgroup without recurrent respiratory infections and controls. It is suggested that the secretory immune system provides local immune protection against pathogens in the respiratory tract. Detection of salivary Ig levels may serve as a predictor of the susceptibility of DS individuals to recurrent respiratory tract infections.

Infections associated with Down Syndrome (DS) are prevalent in the mucosal-gastrointestinal and respiratory systems, for reasons that are uncertain. The purpose of the present study was to assess the levels of parotid salivary immunoglobulins (Ig) in a group of DS individuals as a possible factor in the susceptibility of mucosal surfaces to infections. Twenty-nine DS and 10 age- and sex-matched healthy individuals were included. Salivary flow rate and IgA, IgG, and IgM concentrations were recorded. The secretion rates of IgA and IgG were diminished by 83% (p < 0.001) and 75% (p = 0.05), respectively, whereas the secretion rate of IgM was not statistically significantly lower. Analysis of the data suggests that DS individuals are immunodeficient in the humoral mucosal immune response. This may explain, in part, the high incidence of recurrent infections in target organs of the secretory immune system in DS subjects.

Saliva is essential for oral defense against infections. Decreased salivary secretion may result in increased dental caries, oral mucosal changes, an altered sense of taste, difficulty in swallowing, and oral pain. A review of the literature reveals sporadic and contradictory reports on the use of sialometry and sialochemistry to explain the role of saliva in the oral health and well-being of subjects with Down syndrome. The present study documents parotid gland saliva secretion at different ages in a group of subjects with Down syndrome. Saliva was collected from 39 patients 11 to 62 years old, by means of a parotid salivary gland cup and under standardized conditions of stimulated secretion. The rate of salivary secretion in the entire group of patients with Down syndrome was lower than that of healthy controls and lower in the older study group compared with the younger group. Institutionalized subjects or those living in hostel-like apartments had a lower secretion rate than those living at home. No difference in salivary flow was found between those patients with Down syndrome with normal thyroid output and those with hypothyroidism who were receiving replacement therapy. In a four-way ANOVA with flow as the dependent variable and Down syndrome, hypothyroidism, institutionalization, and age as factors, Down syndrome was found to be the only variable significantly related to flow (p = 0.017). Our findings indicate that stimulated parotid salivary hypofunction in Down syndrome subjects is mainly related to their genetic disorder.

Alterations in the size, morphology and number of teeth are among the many inherited disorders that have been reported in individuals with Down syndrome. By contrast, third molar agenesis and tooth transposition have been largely ignored and the prevalence of canine impaction has not been reported. The intention of this study was to quantify the occurrence of these anomalies in a group of individuals with Down syndrome, using standardized records, which included a clinical examination, dental casts, and a panoramic radiograph. The results show a notably high prevalence of third molar agenesis (74% of individuals older than 14 years), canine impaction (15%), and maxillary canine/first premolar transposition (15%), compared to published figures from random population samples. These anomalies should not be seen as separate, independent entities, but as associated phenomena. The slow rate of cell growth and a consequent reduced cell number that characterize this syndrome may be responsible for the underdevelopment of the upper jaw, the delayed dental development, the reduction in teeth number and size, and the altered path of canine eruption. No explanation, other than genetics, is immediately available to explain why the maxillary canine/first premolar transposition should represent another phenotypic expression of this trisomy.