Treg and TH17 link to immune response in individuals with peri-implantitis: a preliminary report.

BACKGROUND AND OBJECTIVES: Treg and TH17 cells influence the inflammatory process in periodontal diseases and could also play in a similar pattern, an essential role in immune-inflammatory mechanisms involved in the destruction of the peri-implant tissues, peri-implantitis. Therefore, this study evaluated the levels of RORγT and FOXP3 gene expression in subjects with peri-implantitis and healthy peri-implant tissues. METHODS: A total of 35 subjects with implant-supported restorations in both diseased and healthy clinical conditions (n = 15 healthy; n = 20 peri-implantitis) were included in this study. Peri-implantitis was defined as probing depth > 5 mm, bleeding on probing and/or suppuration, and peri-implant bone loss >4 mm. Peri-implant tissue biopsies were collected for analysis of the mRNA, RORγT, and FOXP3 expression levels. The samples were submitted to total RNA extraction, treatment with DNAse, and cDNA synthesis. Subsequently, real-time PCR reaction was performed to evaluate the levels of RORγT and FOXP3 gene expression to the reference gene. These were analyzed by the non-parametric Mann-Whitney method with a level of significance of 5%. RESULTS: Higher gene expression levels of the transcription factors RORγT and FOXP3 were detected in the tissues affected by peri-implantitis when compared with healthy tissues (p < 0.05). CONCLUSIONS: The present study demonstrated the possible existence of a hybrid TH17-Treg profile, based on the gene expression of transcription factors inducing differentiation of these cells. Further studies must be designed to gain a better understanding of the immunological mechanisms involved in the pathogenesis of peri-implantitis. CLINICAL RELEVANCE: The levels of RORγT and FOXP3 transcription factors that were linked to cells with the FOXP3+RORγT+ phenotype could be used as a predictor of peri-implantitis progression.

Expression Levels of Semaphorins 3A, 3B, 4A, and 4D on Human Peri-implantitis.

PURPOSE: To evaluate the gene expression levels of semaphorins 3A, 3B, 4A, and 4D in both healthy and diseased implants. MATERIALS AND METHODS: Subjects with peri-implantitis presented clinical attachment loss, probing depth ≥ 5 mm, bleeding on probing and/or suppuration, and radiographic bone loss > 4 mm. Peri-implant tissue biopsy specimens were sampled for analysis of the mRNA expression levels for semaphorins 3A, 3B, 4A, and 4D. A real-time polymerase chain reaction was performed, and the gene expression levels of semaphorins in relation to the housekeeping gene were analyzed by using the nonparametric Mann-Whitney test (P < .05). RESULTS: Thirty-five subjects (16 men, 19 women; mean age: 54.12 ± 2.34 years) with implant-supported restorations, using screw-shaped dental implants with internal or external hexagon were enrolled in this study. Higher levels of semaphorins 3A and 4D were detected in the peri-implantitis compared with the healthy tissues (P = .0011 and P = .0404, respectively), whereas Sem4A levels were significantly higher in the control group (P < .0001). Differences between groups in the expression levels of Sem3B were not significant. CONCLUSION: Advanced peri-implantitis lesions showed higher levels of gene expression for Sem3A and Sem4D and lower levels of Sem4A in comparison to tissues obtained from a healthy dental implant.