Age-dependent deficiency in saliva and salivary antibodies secretion in Down's syndrome.
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.


METHODS
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.
Department of Orthodontics, Hebrew University-Hadassah School of Dental Medicine, P.O. Box 12272, Jerusalem 91120, Israel. drchaushu@gmail.com
S
S
Chaushu
G
G
Chaushu
M
M
Zigmond
E
E
Yefenof
A
A
Stabholz
J
J
Shapira
J
J
Merrick
G
G
Bachrach
D000328:Adult; D016976:Aggregatibacter actinomycetemcomitans / Q000276:immunology; D000375:Aging / Q000276:immunology*; D000907:Antibodies, Bacterial / Q000032:analysis*; D000917:Antibody Formation; D016022:Case-Control Studies; D004198:Disease Susceptibility; D004314:Down Syndrome / Q000276:immunology*; D005260:Female; D006801:Humans; D007070:Immunoglobulin A / Q000032:analysis*; D008297:Male; D008875:Middle Aged; D010306:Parotid Gland / Q000276:immunology; D016966:Porphyromonas gingivalis / Q000276:immunology; D012463:Saliva / Q000276:immunology*; D012472:Salivation / Q000502:physiology*; D018709:Statistics, Nonparametric; D013295:Streptococcus mutans / Q000276:immunology
D000907:Antibodies, Bacterial; D007070:Immunoglobulin A