Analysis of CD15, CD57 and HIF-1α in biopsies of patients with peri-implantitis.

Peri-implantitis is an infectious disease characterized by inflammation of the tissues surrounding the implant, bleeding on probing with or without suppuration, and bone loss. Peri-implant lesions contain a leukocyte infiltrate of plasma cells, lymphocytes, macrophages and neutrophils. A survey of the literature did not show any studies reporting an association between hypoxia and peri-implantitis. The aim of the present cross-sectional study was to evaluate histological changes and immunostaining for CD15, CD57 and HIF-1α in the peri-implant mucosa of patients with and without peri-implantitis. Mucosal biopsies were obtained from 18 patients with peri-implantitis and 10 control subjects without peri-implantitis at a private health care center between 2010 and 2012. The sections were fixed in 10% buffered formalin, processed and embedded in paraffin for histopathological and immunohistochemical study. Acanthosis, spongiosis and exocytosis were observed in both groups, with no significant difference between them. The peri-implantitis group showed increased immunostaining for CD15, a neutrophil marker, and HIF-1α, a tissue hypoxia marker, but no significant difference in immunostaining for CD57, a Natural Killer cell marker. The increase in neutrophil (CD15) and hypoxia (HIF-1α) markers in patients with peri-implantitis suggests an active participation of neutrophils and hypoxia in the pathogenesis of this disease. Since the present study was the first to evaluate the expression of CD15, CD57 and HIF-1α in peri-implant tissues, further studies should be performed to better understand the role of these molecules in peri-implantitis.

Expression of IL-6, IL-10, IL-17 and IL-33 in the peri-implant crevicular fluid of patients with peri-implant mucositis and peri-implantitis.

OBJECTIVES: The aim of this study was to compare the levels of IL-6, IL-10, IL-17 and IL-33 in the peri-implantar crevicular fluid (PICF) and in parotid gland saliva (PGS) of healthy patients, and peri-implantitis and peri-implant mucositis patients. MATERIALS AND METHODS: The PICF was collected from 40 implants as follows: 10 peri-implant mucositis patients, 20 peri-implantitis patients and 10 healthy patients. The PICF and PGS samples collected from each patient were quantified for IL-6, IL-10, IL-17 and IL-33 by enzymatic immunosorbent assay (ELISA). RESULTS: IL-6, IL-17 and IL-33 levels on PIFC were significantly higher in peri-implantitis group when compared to healthy group. IL-17 and IL-33 levels in PIFC were significantly higher in peri-implant mucositis group than in healthy group. There was no significant difference when comparing IL-6, IL-10, IL-17 and IL-33 levels in PGS among healthy, peri-implant mucositis and peri-implantitis groups. CONCLUSIONS: Therefore, as in patients with peri-implantitis there were significantly higher levels of IL-6, IL-17 and IL-33 in PICF, we believe that these cytokines were intensifying local inflammatory process, and contributing to clinical aspects such as increased marginal bleeding and probing depth found in patients with peri-implantitis. Furthermore, as IL-17 and IL-33 were increased in patients with peri-implant mucositis, hypothesized that these cytokines were also contributing to the inflammatory process observed in this disease.

Evaluation of peri-implant mucosa: clinical, histopathological and immunological aspects.

OBJECTIVE: The aim was to compare the inflammatory response in peri-implant mucosa between patients with peri-implantitis (PP-group) and patients with healthy peri-implant tissues (HP-group). MATERIALS AND METHODS: Two fragments of peri-implant mucosa of 18 patients were collected and serial sections were performed for histological and immunohistochemical analysis. RESULTS: When compared with HP-group, PP-group showed higher immunostained cell density for TGF-ß, IL-17 and CD31, beyond greater density of red cells, leukocytes, mast cells chymase (MCC) and mast cell tryptase (MCT). HP-group patients showed higher IL-13 expression and increased amount of collagen fibres when compared with PP-group. In PP-group there was significant positive correlation between MCT density and density of blood vessels immunostained, and between MCC density and density of blood vessels immunostained. There was significant negative correlation between the IL-17 density and collagen percentage. CONCLUSIONS: This study demonstrated that in patients with peri-implantitis there was higher of TGF-ß and IL-17, indicating that these cytokines are directly involved in the inflammatory process. Thus, understanding the influence of cytokines in the peri-implantitis installation, new therapies could be developed in order to inhibit the synthesis of IL-17 and induce synthesis of IL-13 in peri-implant tissue, contributing to increase the longevity of the implant.