Ontogeny of Secretory Immunity: Levels of Secretory IgA and Natural Antibodies in Saliva

Abstract

SummaryIn 187 healthy subjects from 2 months to 27 years of age, secretory IgA and free secretory component were assayed in samples of whole saliva obtained before and after stimulation with lemon juice. Antibody titers against Escherichia coli 0 antigens and against rabbit erythrocytes were also dosed in unstimulated saliva. Secretory IgA, undetectable in newborns, was present in all 2-month-olds tested in both unstimulated and stimulated saliva; thereafter secretory IgA levels increased progressively, reaching adult values by 6 to 8 years in unstimulated saliva and already by 2 to 4 years in stimulated saliva. The antibody titers assessed in unstimulated saliva followed a similar pattern also reaching adult values by 6 to 8 years. On the other hand, free secretory component levels showed no significant variation with age in unstimulated saliva whereas a slight increase was observed in the first year of life in stimulated saliva. SpeculationThe physiologic deficiency of SIgA and of secretory antibodies in infancy and childhood might well play a role in the pathogenesis of infectious diseases of the respiratory and gastrointestinal tract frequent in this age group.

Does Variability in Salivary Protein Concentrations Influence Oral Microbial Ecology and Oral Health?

“…Strong correlations over time have been reported for parotid saliva densitometric patterns (Oberg et al, 1982), stimulated parotid saliva concentrations of total protein, lysozyme, lactoferrin, and peroxidase , and unstimulated whole saliva concentrations of amylase, total protein, lysozyme, lactoferrin, peroxidase, and slgA Jenzano et al, 1987;Rudney et al, 1993). There is some uncertainty regarding the stability of slgA, since studies have reported conflicting results (Claman et al, 1967;Stuchell and Mandel, 1978;Burgio et al, 1980;Widerstrom and Bratthall, 1984;Bratthall and Widerstrom, 1985;Rudney et al, , 1993. This may be partly an artifact of sample size, since total slgA has been correlated over time in studies involving larger numbers of subjects (Bratthall and Widerstrom, 1985;Gleeson et al, 1991;Rudney etal, 1993).…”

Salivary Immunoglobulin Classes in Nigerians with Periodontitis

“…25 sIgA levels, which are undetectable in newborns, increase progressively and reach adult values in stimulated saliva by 2 to 4 years of age and, in unstimulated saliva, by 6 to 8 years of age. 26 In contrast, salivary IgG is primarily derived from serum via gingival crevicular fluid (GCF) and is present in low concentrations. Consequently, the IgG concentration in saliva should increase as inflammation of the periodontal tissues becomes more severe and vascular permeability increases, resulting in increased flow of GCF.…”

Secretor status and humoral immune responses to Neisseria lactamica and Neisseria meningitidis

“…The full protective potential of secretory IgA is not present in the infant at birth [4,5]. Adult levels of secretory IgA are not reached until after 1 year of age [6,7]. It has been suggested that in infants the presence of IgM compensates partially for the low levels of IgA [7].…”