Age and Oral Disease Effects on Systemic Inflammatory and Immune Parameters in Nonhuman Primates

Center for Oral Health Research, College of Dentistry, University of Kentucky, Lexington, KY; and Caribbean Primate Research Center, University of Puerto Rico, Sabana Seca, PR

	Abstract

This report evaluated systemic inflammatory and immune biomarkers in a cohort of Macaca mulatta (rhesus monkeys) maintained as a large family social unit, including an age range from <1 year old to >24 years old. We hypothesized that the systemic host responses would be affected with age, gender, and clinical oral presentation of the population, contributing to inflammatory and immune responses that would reflect chronic oral infections. The results demonstrated that the prevalence and severity of periodontitis, including missing teeth, increased significantly with age. Generally, minimal differences in clinical parameters were noted between the genders. Systemic inflammatory mediators, including acute phase reactants, prostaglandin E₂ (PGE₂), cytokines/chemokines, and selected matrix metalloproteinases (MMP) demonstrated significant differences in the various age groups of animals. Many of these were increased with age, although PGE₂, RANTES, bactericidal permeability inducing factor (BPI), MMP-1, and MMP-9 were significantly increased in the young group (1-3 years old) compared to the older animals. We observed that in the adult and aged animals, the systemic inflammatory mediator levels were significantly elevated related to gingival inflammation and periodontal tissue destruction. Serum antibody levels to a battery of periodontal pathogens in the young animals were generally <50% of those in the adults, and were significantly related with aging in the cohort. The antibody levels, particularly to P. gingivalis, F. nucleatum, and T. forsythia, were most significantly elevated in animals with periodontal disease, irrespective of the age of the animal. These results provide a broad description of oral health and host responses in a large cohort of nonhuman primates from very young animals to the aged of this species. The findings afford a base of data to examine the ontogeny of host responses at mucosal sites, such as the gingival tissues.