Secretory immune status of oral cavity in the patients with Сandida-associated denture stomatitis

Age-related changes in the oral mucosa immunity, including decreased contents of secretory immunoglobulins and antimicrobial peptides in saliva, along with changed balance of pro- and antiinflammatory cytokines, care risks for development of purulent-inflammatory or allergic diseases of the oral cavity. For example, denture stomatitis (DS) caused by Candida albicans occurs in about 30—70% of denture users. The purpose of this study was to assess the secretory immune state of oral mucous membranes in the patients with Candida-associated denture stomatitis. We examined 42 elderly patients (61-72 years old) with one-piece acrylic dentures for at least, 6 months (15 men and 27 women). Based on clinical and microbiological studies, the patients were divided into a group with DS (n = 24) and a group without DS (n = 18). The contents of secretory immunoglobulin A (sIgA) and proinflammatory cytokines was determined, i.e., interleukin-1β (IL-1β), interleukin-6 (IL-6), interleukin-8 (IL-8), tumor necrosis factor-α (TNFα), and anti-inflammatory cytokines, e.g., receptor antagonist of interleukin-1 (RAIL), interleukin-4 (IL-4), interleukin-10 (IL-10), as well as antimicrobial peptides (cathelicidin LL-37, lactoferrin and alphadefensins 1-3 (HNP1-3). The sIgA levels in the salivary fluid of patients with DS (0.92 (0.80-1.26) g/l) were significantly lower (p < 0.05) than in patients without stomatitis (1.71 (1.23-2,13) g/l). In the group with advanced DS, a significant increase of IL-1β levels in saliva was observed, along with simultaneous decrease of IL-8 concentrations, compared to the other group, without differences in TNFα and IL-6 concentrations. Increased contents of IL-10 in saliva was also noted. It was shown that the concentrations of cathelicidin LL-37 in saliva of the DS patients was increased two-fold, whereas the contents of neutrophil-derived alpha-defensins (HNP 1-3) was decreased. Conclusions: The development of inflammation in denture stomatitis caused by usage of removable acrylic dentures associated with Candida albicans infection is characterized by functional insufficiency of the secretory immunity of the oral mucosa associated with decreased amounts of secretory immunoglobulin A and antimicrobial peptides of neutrophilic origin. Low levels of alpha-defensins may suggest a decrease in the functional activity of neutrophils in the elderly, thus leading to higher susceptibility to fungal infection of oral cavity.