Salivary Concentration of Secretory Leukocyte Protease Inhibitor, an Antimicrobial Protein, Is Decreased with Advanced Age

Abstract

Background: Secretory leukocyte protease inhibitor (SLPI) exhibits antimicrobial activities that, in addition to other well-characterized proteins such as lysozyme and lactoferrin, is thought to play a critical role in mucosal defenses. Although elderly individuals are particularly susceptible to mucosal infections, salivary production of SLPI has not been assessed in an aged cohort. Objectives: Hypothesizing that oral SLPI concentrations are reduced with advanced age, this cross-sectional study compared SLPI concentrations to concentrations of lysozyme, lactoferrin and total protein in unstimulated salivary secretions of healthy, community-dwelling 79+-year-old and younger adults. Methods: Study participants were 45 non-hospitalized dentate adults aged 79–89 (23 elderly) or 21–51 years (22 non-elderly). Home-based interviews and clinical examinations determined dentate status and confirmed the absence of dentures, oral mucosal disease, anti-infective medication use, irradiation therapy for head and neck cancer and self-perceived xerostomia. Whole unstimulated saliva was collected from all subjects and analyzed for antimicrobial protein concentration by enzyme-linked immunosorbent assay and for total protein content by the bicinchoninic acid method. Bivariate and multivariate (generalized linear modeling) analyses evaluated the relationships between age, gender and salivary protein concentrations. Results: Mean salivary levels of SLPI and lysozyme were lower in elderly compared with non-elderly subjects (p < 0.001), unlike lactoferrin and total protein levels. Similar results were obtained when concentrations of the individual proteins were normalized to the total protein concentration, suggesting that glandular production of SLPI and lysozyme preferentially decreases with aging. Gender differences were detected only for SLPI concentrations; males had lower SLPI levels than females regardless of age (p < 0.01). Generalized linear models confirmed that age (p < 0.001) and gender (p < 0.05) were each associated with the SLPI concentration and together accounted for 50% of the variation in SLPI concentration in this population. Conclusion: These findings indicate that SLPI production is diminished among healthy community-dwelling older adults, particularly elderly males. Further investigation should determine the impact of decreased local SLPI production on the increased risk of oral mucosal disease with advanced age.

HPV Prevalence and Concordance in the Cervix and Oral Cavity of Pregnant Women

“…Thus it is likely that the mechanism of risk or detectability is associated with other factors. Oral saliva has been shown to be protective against infections through the existence of a number of oral antimicrobial agents such as lysozyme, lactoferrin, sIgA and cytokines [30][31][32] . In addition, the highly keratinaized tissue that characterizes the oral cavity may provide a barrier against HPV infection, making it less likely that the virus will invade and reach the basal cell layer than in the cervical mucosa.…”

Anti-Inflammatory and Antimicrobial Roles of Secretory Leukocyte Protease Inhibitor

“…Shugars et al found that salivary SLPI concentrations diminish with aging. Hence, the proclivity of the elderly toward oral fungal infections may, in part, be due to reduced salivary SLPI levels compared to those in younger adults (43).…”

Detección de VPH en boca y cérvix de pacientes con diagnóstico citológico sugestivo de infección genital

“…Se ha sugerido que esta diferencia entre ambas regiones anatómi-cas pueda deberse a características de la mucosa oral que no comparte la mucosa cervical, incluyendo el tejido queratinizado que actuaría como una barrera contra infecciones microbianas, dificultando el paso del virus a la capa de células basales. Además, la saliva contiene agentes antimicrobianos como IgA, citoquinas, lactoferrina y lisozima cuya producción incrementa durante procesos infecciosos, tal como se ha registrado en respuesta a micosis; estos agentes también protegen contra la infección por VPH 10,14,15 . Sin embargo, otros investigadores consideran que la diferencia en la frecuencia de VPH detectada en las mucosas oral y genital sugiere que la infección genital no es necesariamente un factor predisponente para la infección oral en el mismo paciente y que ésta puede ser considerada un evento independiente 16 .…”