Analysis of the cytokine profiles of the synovial fluid in a normal temporomandibular joint: Preliminary study

The purpose of this study was to compare the cytokine profiles of the synovial fluid from the temporomandibular joint (TMJ) spaces of normal individuals and temporomandibular disorder (TMD) patients. Thirty-four patients with planned orthognathic surgery did not present abnormalities of the TMJ on magnetic resonance images and radiographs and did not show the symptoms identified by the Research Diagnostic Criteria for TMD (RDC-TMD); as a result, they were assigned to the control group. Twenty-two patients who sought treatment for TMD during the same period were assigned to the TMD group. Synovial fluid was collected from superior TMJ spaces, and cytokine expression was analysed by an enzyme-linked immunosorbent assay (ELISA). Significant differences were tested using Fisher's exact test (p < 0.05). Granulocyte Macrophage Colony stimulating Factor (GM-CSF), interferon (INF), interleukin (IL)-1β, IL-2, IL-6, IL-8, IL-10 and tumour necrosis factor (TNF)-α were detected in the TMD group, whereas no cytokines were detected in the control group. The most prevalent cytokines in the TMD group were IL-1β, IL-6 and GM-CSF. IL-4 and IL-5 were not detected in either the TMD group or in the control group. None of the cytokines that were detected in patients with TMD were found in the articular spaces of normal individuals.     

Clinical diagnosis of temporomandibular joint arthritis

Evidence‐based clinical diagnostic criteria for temporomandibular joint (TMJ) arthritis are not available. To establish (i) criteria for clinical diagnosis of TMJ arthritis and (ii) clinical variables useful to determine inflammatory activity in TMJ arthritis using synovial fluid levels of inflammatory mediators as the reference standard. A calibrated examiner assessed TMJ pain, function, noise and occlusal changes in 219 TMJs (141 patients, 15 healthy individuals). TMJ synovial fluid samples were obtained with a push–pull technique using the hydroxycobalamin method and analysed for TNF, TNFsRII, IL‐1β, IL‐1ra, IL‐1sRII, IL‐6 and serotonin. If any inflammatory mediator concentration exceeded normal, the TMJ was considered as arthritic. In the patient group, 71% of the joints were arthritic. Of those, 93% were painful. About 66% of the non‐arthritic TMJs were painful to some degree. Intensity of TMJ resting pain and TMJ maximum opening pain, number of jaw movements causing TMJ pain and laterotrusive movement to the contralateral side significantly explained presence of arthritis (AUC 0.72, P < .001). Based on these findings, criteria for possible, probable and definite TMJ arthritis were determined. Arthritic TMJs with high inflammatory activity showed higher pain intensity on maximum mouth opening (P < .001) and higher number of painful mandibular movements (P = .004) than TMJs with low inflammatory activity. The combination TMJ pain on maximum mouth opening and Contralateral laterotrusion <8 mm appears to have diagnostic value for TMJ arthritis. Among arthritic TMJs, higher TMJ pain intensity on maximum mouth opening and number of mandibular movements causing TMJ pain indicates higher inflammatory activity.     

Th1/Th17/Th22 immune response and their association with joint pain,imagenological bone loss,RANKL expression and osteoclast activity in temporomandibular joint osteoarthritis: A preliminary report

It is well accepted that the presence of cytokines belonging to the Th1/Th17/Th22 axis of immuno‐inflammatory response in the joint environment, such as IL‐1β, IL‐17 and IL‐22, respectively, are associated with pathogenesis of several synovial joint degenerative disorders. During temporomandibular joint osteoarthritis (TMJ‐OA), IL‐1β and IL‐17 have been implicated in the inflammation and resorption of sub‐chondral bone; however, the role of Th22 response in the TMJ‐OA pathophysiology has not been established. This study aimed to compare the expression of Th1/Th17/Th22‐type cytokines, chemokines and chemokine receptors in synovial fluid samples obtained from TMJ‐OA or disk displacement with reduction (DDWR) patients. In addition, it aimed to associate these levels with joint pain, imagenological signs of bone degeneration, RANKL production, osteoclastogenesis and osteoclast‐induced bone resorption. Higher levels of IL‐1β, IL‐17 and IL‐22 were expressed in TMJ‐OA compared with DDWR subjects, and these increased levels significantly correlated with RANKL expression, joint pain and articular bone degeneration. Higher levels of CCR5, CCR6 and CCR7, as well as their respective ligands CCL5 and CCL20, responsible for recruitment of IL‐1β, IL‐17 and IL‐22‐producing cells, were over‐expressed in TMJ‐OA compared with DDWR subjects. Osteoclastogenesis and osteoclast‐induced bone resorption were significantly greater in presence of synovial fluid from TMJ‐OA compared with DDWR subjects. These data demonstrate that cytokines, CCLs and CCRs associated with the Th1/Th17/Th22 axis of immuno‐inflammatory response are involved in TMJ‐OA pathogenesis. These findings suggest that IL‐22 is involved in the RANKL expression in TMJ‐OA, which in turn induces differentiation of osteoclasts and subsequent resorption of sub‐chondral bone.     

Effects of interleukin‐1β and tumor necrosis factor‐α on macrophage inflammatory protein‐3α production in synovial fibroblast‐like cells from human temporomandibular joints

Background

Interleukin‐1β (IL‐1β) and tumor necrosis factor‐α (TNF‐α) are key mediators of the intracapsular pathological conditions of the temporomandibular joint (TMJ). Therefore, the gene expression profiles in synovial fibroblast‐like cells (SFCs) from patients with internal derangement of the TMJ were examined after they were stimulated with IL‐1β or TNF‐α to determine which genes were altered.

Methods

Ribonucleic acid was isolated from SFCs after IL‐1β or TNF‐α treatment. Gene expression profiling was performed using oligonucleotide microarray analysis. On the basis of the results of this assay, we investigated the kinetics of macrophage inflammatory protein‐3α (MIP‐3α) gene expression using PCR, and protein production in TMJ SFCs stimulated by IL‐1β or TNF‐α using an ELISA. Inhibition experiments were performed with MAPK and NFκB inhibitors. SFCs were stimulated with IL‐1β or TNF‐α after treatment with inhibitors. The MIP‐3α levels were measured using an ELISA.

Results

Macrophage inflammatory protein‐3α was the gene most upregulated by IL‐1β‐ or TNF‐α stimulation. The mRNA and protein levels of MIP‐3α increased in response to IL‐1β in a time‐dependent manner. In contrast, during TNF‐α stimulation, the MIP‐3α mRNA levels peaked at 4 h, and the protein levels peaked at 8 h. In addition, the IL‐1β‐ and TNF‐α‐stimulated MIP‐3α production was potently reduced by the MAPK and NFκB signaling pathway inhibitors.

Conclusion

Interleukin‐1β and TNF‐α increased the MIP‐3α production in SFCs via the MAPK and NFκB pathways. These results suggest that the production of MIP‐3α from stimulation with IL‐1β or TNF‐α is one factor associated with the inflammatory progression of the internal derangement of the TMJ.     

Local effects of intra-articular injection of anti-rabbit tumor necrosis factor alpha monoclonal antibody in antigen-induced arthritis of the rabbit temporomandibular joint

J Oral Pathol Med (2012) 41 : 96–105 Background: Local effects of intra‐articular (IA) injection of anti‐rabbit tumor necrosis factor alpha monoclonal antibody (anti‐TNFα mAb) for antigen‐induced mono‐arthritis (AIA) of the rabbit temporomandibular joint (TMJ) and its systemic influences were evaluated. Methods: Biochemical analysis of synovial fluid (SF), clinical and histopathological analyses of TMJ, and serum analysis were performed after inducing AIA in bilateral TMJs of 40 New Zealand White rabbits. IA injection of anti‐TNFα mAb in unilateral TMJ (TNF blockade side; n = 12) and IgG (n = 12) was performed while saline injected on the contralateral side. TNFα and IL‐1β in SF was analyzed at Days 1, 3, 7, and 21. Joint swelling and head withdrawal reflex threshold (WRT) over TMJs were evaluated in TNF blockade side (n = 12) with histopathological analysis at Days 3, 7, and 21. In remaining four animals with TNF blockade, TNFα and anti‐TNFα mAb in serum were analyzed. Results: Tumor necrosis factor alpha in SF was significantly lower in TNF blockade side on all days but IL‐1β was lower only on Day 3. WRT was significantly higher at all times in the blockade side. Less inflammatory reactions and degenerative changes of cartilage were observed on Days 7 and 21 in the blockade side. TNFα and anti‐TNFα mAb were under detection level in serum at all times. Conclusions: Intra‐articular injection of anti‐rabbit TNFα mAb in mono‐arthritis model was effective to control local inflammation and degenerative joint changes. Further, low‐dose IA injection of antibody may not have systemic side effects.     

Tumor necrosis factor mediates temporomandibular joint bone tissue resorption in rheumatoid arthritis

Abstract

Objective. To investigate if TNF, IL-1 or their endogenous controls, in relation to ACPA, are associated with radiological signs of ongoing temporomandibular joint (TMJ) bone tissue resorption and disc displacement in RA patients. Methods. Twenty-two consecutive outpatients with TMJ of RA were included. Systemic inflammatory activity was assessed by DAS28. The number of painful regions in the body and ESR, CRP, RF and ACPA were analyzed. TMJ synovial fluid and blood samples were obtained and analyzed for TNF, TNFsRII, IL-1ra, IL-1sRII and ACPA. The ratios between the mediators and their endogenous control receptors were used in the statistical analysis. Magnetic resonance imaging was performed in closed- and open-mouth positions and evaluated regarding disc position and presence of condylar and temporal erosions of the TMJ. Results. A high TNF level in relation to TNFsRII in TMJ synovial fluid correlated to the degree of TMJ condylar erosion. A high IL-1ra level in relation to TNF in TMJ synovial fluid was also correlated to the degree of TMJ condylar erosion. The total degree of TMJ condylar erosion was correlated with the number of painful regions. Conclusion. This study indicates that TNF in TMJ synovial fluid mediates TMJ cartilage and bone tissue resorption in RA. The study also suggests that the degree of endogenous cytokine control is of importance for development of bone tissue destruction.     

Proinflammatory cytokines detectable in synovial fluids from patients with temporomandibular disorders

Objective. To measure the levels of the proinflammatory cytokines, interleukin (IL)-1β, IL-6, tumor necrosis factor- (TNF)α, IL-8, and interferon- (IFN) γ in synovial fluid samples taken from patients with temporomandibular disorders (TMD).Study design. We studied 6 asymptomatic volunteers and 51 patients with TMD. The IL-1β, IL-6, TNF-α, IL-8, and IFN-γ levels in temporomandibular joint synovial fluid were measured using enzyme-linked immunosorbent assay.Results. Measurable level of at least one cytokine in the synovial fluid was found in 40 (64.5%) of 62 joints in the patients: IL-1β and IFN-γ were each detected in 18 (29.0%) of 62 joints; IL-6 in 13 (21.0%) of 62 joints; IL-8 in 11 (19.3%) of 57 joints; and TNF-α in only 5 (8.1%) of 62 joints. None of these cytokines was detectable in the synovial fluid in the control group. Furthermore, there was a strong correlation between the detection of IL-1β and pain in the joint area.Conclusions. These data clearly demonstrate increased levels of several proinflammatory cytokines in certain patients with TMD and suggest that these cytokines may play a role in the pathogenesis of synovitis and degenerative changes of the cartilaginous tissue and bone of the temporomandibular joint.     

Up-regulation of interleukin-6 and vascular endothelial growth factor-A in the synovial fluid of temporomandibular joints affected by synovial chondromatosis

Our aim was to explore important inflammatory mediators for synovial chondromatosis in the temporomandibular joints (TMJs) by analysing synovial fluid. Samples were collected from 10 patients with unilateral synovial chondromatosis of the TMJ. Control samples were obtained from 11 subjects with no symptoms in the TMJ. Concentrations of aggrecan, interleukin (IL)-2, IL-4, IL-5, IL-6, IL-8 (CXCL8), IL-10, interferon (IFN)-γ, tumour necrosis factor (TNF)-α and vascular endothelial growth factor (VEGF)-A were measured in the samples of synovial fluid, and the results in the two groups compared. The tissues from the affected TMJ were examined histologically and immunohistochemically. Of the proteins evaluated, the concentrations of aggrecan, IL-6, and VEGF-A were significantly higher in the group with synovial chondromatosis. The immunohistochemical analysis showed that the synovial cells around the osteocartilaginous nodules were vigorously expressing VEGF-A.     

Interleukin‐1 β, interleukin‐12 and interleukin‐18 levels in gingival fluid and serum of patients with gingivitis and periodontitis

Introduction: Cytokines are of major importance in periodontal disease progression. Interleukin‐12 (IL‐12) stimulates interferon‐γ production by T helper type 1 (Th1) cells while IL‐18 induces Th1 responses when present with IL‐12 but Th2 responses in the absence of IL‐12. IL‐1β has been correlated with periodontal disease destruction. This study determined the local concentrations of these cytokines in sites of gingivitis and periodontitis. Methods: Gingival crevicular fluid was collected from two sites in each of 10 gingivitis patients and from two gingivitis sites and two periodontitis sites from each of 10 periodontitis patients. Serum samples were also collected. IL‐1β, biologically active IL‐12 p70, the IL‐12 p40 subunit and IL‐18 concentrations were determined by enzyme‐linked immunoabsorbent assay. Results: IL‐1β and IL‐18 concentrations were higher in the gingival crevicular fluid from periodontitis patients than in that from gingivitis patients; IL‐18 concentrations were higher than those of IL‐1β. Very little IL‐12, either p40 or p70, was detected in the gingival crevicular fluid samples. In the serum, very low levels of cytokines were found. The level of serum IL‐12 p40, however, was higher than in the fluid from periodontitis sites of periodontitis patients. Conclusion: The local production of IL‐1β and IL‐18 in the gingival crevicular fluid increased with increasing inflammation and IL‐18 was the predominant cytokine at both gingivitis and periodontitis sites. Very little IL‐12 was detected with levels decreasing with increasing inflammation. These results suggest that there is an association between severity of periodontal disease and levels of IL‐1, IL‐12 and IL‐18.     

Blocking Proinflammatory Cytokine Release Modulates Peripheral Blood Mononuclear Cell Response to Porphyromonas gingivalis

Background: Chronic periodontitis (CP) is an inflammatory disease in which cytokines play a major role in the progression of disease. Anti‐inflammatory cytokines (interleukin 4 [IL‐4] and IL‐10) were reported to be absent or reduced in diseased periodontal tissues, suggesting an imbalance between the proinflammatory and anti‐inflammatory mediators. This study tests the hypothesis that there is cellular crosstalk mediated by proinflammatory and anti‐inflammatory cytokines and that blocking proinflammatory cytokine (tumor necrosis factor‐α [TNF‐α] and IL‐1) production will enhance anti‐inflammatory cytokine (IL‐4 and IL‐10) production from peripheral blood mononuclear cells (PBMCs) in response to Porphyromonas gingivalis. Methods: PBMCs were isolated from individuals diagnosed with CP or healthy individuals and cultured for 24 hours. Concanavalin A (ConA) was used as an activator of lymphocyte function. Live and heat‐killed P. gingivalis or lipopolysaccharide from P. gingivalis were used as the bacterial stimulants. TNF‐α and IL‐1 production was neutralized by specific antibodies against TNF‐α and IL‐1α or IL‐β. Culture supernatants were evaluated by enzyme‐linked immunosorbent assay for TNF‐α, IL‐1β, IL‐4, and IL‐10 production. Results: Live P. gingivalis did not result in any significant IL‐10 or IL‐4 release, whereas heat‐killed P. gingivalis led to a significant increase in IL‐10 levels compared with unstimulated or live P. gingivalis–stimulated cells from both healthy individuals or those with CP. Overall, PBMCs from patients with CP produced significantly lower IL‐10 in response to ConA and P. gingivalis, suggesting chronic suppression of the anti‐inflammatory cytokine production. Blocking the proinflammatory cytokine response did not result in any substantial change in IL‐10 or IL‐4 response to live P. gingivalis. Blocking the proinflammatory cytokine response restored IL‐10 production by cells from CP in response to P. gingivalis lipopolysaccharide. Conclusions: These findings suggest that PBMCs from patients with CP have suppressed anti‐inflammatory cytokine production that can, in part, be restored by neutralizing proinflammatory cytokines. Monocytes are an important source of IL‐10 production, and monocyte‐derived IL‐10 might play a regulatory role in the pathogenesis of CP.     

Tumor Necrosis Factor‐α and Interleukin (IL)‐1β, IL‐6, and IL‐8 Impair In Vitro Migration and Induce Apoptosis of Gingival Fibroblasts and Epithelial Cells,Delaying Wound Healing

Background: Multiple factors affect oral mucosal healing, such as the persistence of an inflammatory reaction. The present study evaluates effects of tumor necrosis factor (TNF)‐α and interleukin (IL)‐1β, IL‐6, and IL‐8 on epithelial cells (ECs) and human gingival fibroblasts (GFs) in vitro. Methods: GFs and ECs were seeded in 96‐well plates (1 × 10⁴ cells/well) in plain culture medium (Dulbecco’s modified Eagle’s medium [DMEM]) containing 1% antibiotic/antimycotic solution and 10% fetal bovine serum, and incubated for 24 hours. Both cell lines were exposed for 24 hours to the following cytokines: 1) TNF‐α (100 ng/mL); 2) IL‐1β (1 ng/mL); 3) IL‐6 (10 ng/mL); and 4) IL‐8 (10 ng/mL). All cytokines were diluted in serum‐free DMEM. Control cultures were exposed only to serum‐free DMEM. Effects of exposure to inflammatory cytokines were determined by means of: 1) apoptosis (anexin V); 2) cell migration (wound healing assay); 3) inflammatory cytokine synthesis (enzyme‐linked immunosorbent assay). Data were analyzed by Kruskal–Wallis and Mann–Whitney U tests (α = 0.05). Results: Increased apoptosis rates were noted when cells were exposed to inflammatory cytokines, except ECs exposed to IL‐1β. Cell migration was negatively affected by all inflammatory cytokines for both cell lines. ECs and GFs exposed to IL‐6 and IL‐8 significantly increased synthesis of TNF‐α and IL‐1β. Conclusions: Demonstrated results indicate negative effects of tested inflammatory cytokines on ECs and GFs, inducing apoptosis and impairing cell migration. These results can justify delayed oral mucosa healing in the presence of inflammatory reaction.     

The influence of sex hormones on proinflammatory cytokines in gingiva of periodontally healthy premenopausal women

Markou E, Boura E, Tsalikis L, Deligianidis A, Konstantinidis A. The influence of sex hormones on proinflammatory cytokines in gingiva of periodontally healthy premenopausal women. J Periodont Res 2011; 46: 528–532. © 2011 John Wiley & Sons A/S Background and Objective: The aim of this work was to investigate any correlation between the fluctuation of levels of specific proinflammatory cytokines in gingival crevicular fluid and the fluctuation of sex hormones in peripheral blood at ovulation and progesterone peak. Material and Methods: Eighteen premenopausal women with normal and consistent menstrual cycles and healthy periodontium were included in this study. The exclusion criteria were as follows: (i) pregnancy; (ii) use of oral contraceptives; (iii) metabolic or systemic disease that might affect the periodontium; (iv) use of antimicrobial or nonsteroidal anti‐inflammatory drugs during the past 6 mo; and (v) smoking. The measurements were performed at two specific time points for each participant [(i) on the day of ovulation; and (ii) on the day of the progesterone peak) and included the following: (i) plaque index; (ii) bleeding on probing; and (iii) the gingival crevicular fluid levels of interleukin (IL)‐1β, IL‐6, IL‐8 and tumor necrosis factor‐α (TNF‐α). Results: During the menstrual cycle, plaque index values remained unchanged (0.71 ± 0.07 at ovulation; 0.73 ± 0.08 at progesterone peak; p > 0.05), as did bleeding on probing (0.35 ± 0.07 at ovulation; 0.41 ± 0.07 at progesterone peak; p > 0.05). At ovulation, mean gingival crevicular fluid levels were as follows: IL‐1β, 13.3 pg/sample; IL‐6, 5.9 pg/sample; IL‐8, 18.7 pg/sample; and TNF‐α, 25.9 pg/sample. The corresponding values at progesterone peak were as follows: 14.1, 10.1, 19.5 and 26.3 pg/sample. Only IL‐6 gingival crevicular fluid levels were significantly different between ovulation and progesterone peak (p < 0.05). This could reflect sensitivity to subclinical amounts of plaque and biofilm constituents. Conclusion: The subclinical increase of IL‐6 at progesterone peak is not accompanied by clinical changes in the periodontium.     

Analysis of tumor necrosis factor-alpha, interleukin-6, interleukin-1beta, soluble tumor necrosis factor receptors I and II, interleukin-6 soluble receptor, interleukin-1 soluble receptor type II, interleukin-1 receptor antagonist, and protein in the synovial fluid of patients with temporomandibular joint disorders

OBJECTIVE: To measure the levels of various cytokines, cytokine receptors, and cytokine antagonists in the synovial fluid of patients with temporomandibular disorders (TMD) and to determine the correlations among these expression levels. STUDY DESIGN: Synovial fluid was obtained from 55 patients with TMD and from 5 asymptomatic healthy volunteers as controls. The concentrations of tumor necrosis factor (TNF)-alpha, interleukin (IL)-6, IL-1beta, soluble tumor necrosis factor receptors I and II (sTNFR-I and sTNFR-II), IL-6 soluble receptor (IL-6sR), IL-1 soluble receptor type II, and IL-1 receptor antagonist were determined by enzyme-linked immunosorbent assay. RESULTS: The concentrations of TNF-alpha, IL-6, IL-1beta, sTNFR-I, and sTNFR-II were significantly higher in the synovial fluid of patients than in controls (P < .05). TNF-alpha level was positively correlated with those of IL-6, sTNFR-I, and sTNFR-II. In particular, there was a highly significant positive correlation between sTNFR-I and sTNFR-II. CONCLUSION: TNF and sTNFRs in the synovial fluid of patients with TMD may be important in the pathogenesis of these disorders.     

Is There an Interaction Between Polycystic Ovary Syndrome and Gingival Inflammation?

Background: The aim of this study is to evaluate the gingival crevicular fluid (GCF), saliva, and serum concentrations of tumor necrosis factor‐α (TNF‐α), TNF‐α receptor‐1 (TNF‐αR1), TNF‐αR2, and interleukin‐6 (IL‐6) in non‐obese females with polycystic ovary syndrome (PCOS) and either clinically healthy periodontium or gingivitis. Methods: Thirty‐one females with PCOS and healthy periodontium, 30 females with PCOS and gingivitis, and 12 systemically and periodontally healthy females were included in the study. GCF, saliva, and serum samples were collected, and clinical periodontal measurements, body mass index, and Ferriman‐Gallwey score (FGS) were recorded. Sex hormones, cortisol, and insulin levels were measured. TNF‐α, TNF‐αR1, TNF‐αR2, and IL‐6 were determined by enzyme‐linked immunosorbent assay. Kruskal‐Wallis followed by Bonferroni‐corrected post hoc Mann‐Whitney U tests were used to analyze the data. Results: The PCOS + gingivitis group revealed significantly higher GCF, saliva, and serum IL‐6 concentrations than the PCOS + healthy group (P <0.0001). The two PCOS groups exhibited significantly higher saliva TNF‐α concentrations than the control group (P = 0.024 and P = 0.013, respectively). The FGS index was significantly higher in the PCOS + gingivitis group than the PCOS + healthy group (P = 0.030). The PCOS + gingivitis group revealed significantly higher insulin concentration than the PCOS + healthy and control groups (P = 0.014 and P <0.0001, respectively). Serum TNF‐α, TNF‐αRs, and serum, GCF, and salivary IL‐6 levels correlated with the clinical periodontal measurements. Conclusions: PCOS and gingival inflammation appear to act synergistically on the proinflammatory cytokines IL‐6 and TNF‐α. Thus, PCOS may have an impact on gingival inflammation or vice versa. Additional studies are warranted to clarify the possible relationship between PCOS and periodontal disease.     

Can Peri‐Implant Crevicular Fluid Assist in the Diagnosis of Peri‐Implantitis? A Systematic Review and Meta‐Analysis

Background: A broader understanding of the immune inflammatory profile of peri‐implant diseases could be helpful in the development of host‐targeted preventive and therapeutic strategies. The aim of this study is to answer two clinical questions: 1) whether patients with peri‐implantitis (PP) present higher prevalence of any specific inflammatory cytokine in peri‐implant crevicular fluid (PICF) compared with healthy patients; and 2) whether local inflammation measured in PICF can be used as a predictor for incipient PP. Methods: A systematic review of the literature on the most common cytokines released in PICF in healthy and PP‐affected sites was conducted from 1996 up to and including October 2013 using predefined search strategies. Cross‐sectional and prospective longitudinal studies were considered. Meta‐analyses were done separately for healthy, mucositis (MU), and PP outcomes. Results: Interleukin (IL)‐1β was the most studied cytokine (n = 12), followed by tumor necrosis factor (TNF)‐α (n = 10). Other cytokines were also linked to PP, such as IL‐4, IL‐6, IL‐8, IL‐10, IL‐12, and IL‐17. Statistical differences were revealed when IL‐1β release was compared between healthy implant sites and PP (P = 0.001) or MU sites (P = 0.002), respectively; when PP and MU were compared, no statistical differences could be detected (P = 0.80). For TNF‐α release, significant differences were found between healthy and PP implants (P = 0.02). Conclusions: PICF containing inflammatory mediators, such as IL‐1β and TNF‐α, can be used as additional criteria for a more robust diagnosis of peri‐implant infection. Additionally, once the inflammatory process is installed, no differences were found between peri‐implant MU and PP.     

Distinct roles for interleukin‐12p40 and tumour necrosis factor in resistance to oral candidiasis defined by gene‐targeting

Cell‐mediated immunity is important for anti‐Candida host defence in mucosal tissues. In this study we used cytokine‐specific gene knockout mice to investigate the requirement for T helper type 1 (Th1) and Th2 cytokines in recovery from oral candidiasis. Knockout mice used in this study included interleukin‐4 (IL‐4), IL‐10, IL‐12p40, interferon‐γ (IFN‐γ), and tumour necrosis factor (TNF). The mice were challenged either orally or systemically with Candida albicans yeasts, and levels of colonization were determined. IL‐12p40 knockout mice developed chronic oropharyngeal candidiasis, but were not more susceptible to systemic challenge. On the other hand, TNF knockout mice displayed increased susceptibility to both oral and systemic challenge, but only in the acute stages of infection. TNF apparently has a protective effect in the acute stages of both oral and systemic candidiasis, whereas IL‐12p40 is essential for recovery from oral but not systemic candidiasis. The role of IL‐12p40, and its relation to T‐cell‐mediated responses remain to be determined.     

Short‐Term Effects of Non‐Surgical Periodontal Treatment on the Gingival Crevicular Fluid Cytokine Profiles in Sites With Induced Periodontal Defects: A Study on Dogs With and Without Streptozotocin‐Induced Diabetes

Background: The aim of this study is to assess the short‐term effects of non‐surgical periodontal therapy (NSPT) on the gingival crevicular fluid (GCF) cytokine profile in sites with standardized periodontal bony defects in beagle dogs with and without diabetes. Methods: Four beagle dogs with streptozotocin (STZ)‐induced diabetes and four healthy dogs were included. Fasting blood glucose levels were measured using a glucometer. In all animals, a 3‐walled bony defect was created on the mesial surface of the second premolar and first molar in all quadrants. After 12 weeks, all animals underwent weekly NSPT for 3 weeks. Baseline and post‐NSPT GCF samples were collected, and levels of interleukin (IL)‐1, IL‐1β, IL‐6, IL‐8, and tumor necrosis factor (TNF)‐α were measured using enzyme‐linked immunosorbent assay. Statistical analyses were performed using a software program, and P values <0.05 were considered statistically significant. Results: Mean fasting blood glucose levels were significantly higher in dogs with induced diabetes than those without diabetes (P <0.01). At baseline, mean IL‐6 (P <0.01) and IL‐8 (P <0.05) levels were higher in dogs with diabetes than those without diabetes. A significant reduction in levels of IL‐1, IL‐1β, IL‐6, IL‐8, and TNF‐α was noted in dogs without diabetes 1 week after NSPT. However, this significant reduction (P <0.05) only appeared 2 weeks after NSPT in dogs with diabetes. Conclusions: NSPT reduces GCF levels of proinflammatory cytokines in dogs with and without STZ‐induced diabetes; however, chronic hyperglycemia seems to retard the effect of NSPT on GCF cytokine concentration.     

Interleukin‐6 Family of Cytokines in Crevicular Fluid of Renal Transplant Recipients With and Without Cyclosporine A–Induced Gingival Overgrowth

Background: Interleukin (IL)‐6 family of cytokines, including IL‐6, oncostatin M (OSM), leukemia inhibitory factor (LIF), and IL‐11, have fibrogenic features. The current study determines gingival crevicular fluid (GCF) levels of fibrosis‐related IL‐6–type cytokines in cyclosporine A (CsA)–induced gingival overgrowth (GO). Methods: Eighty non‐smokers were included (40 CsA‐medicated renal transplant patients with GO [GO + ; n = 20] or without GO [GO?; n = 20], 20 individuals with gingivitis, and 20 healthy participants). Probing depth and plaque, papilla bleeding, and hyperplastic index scores were recorded. GCF samples were obtained from the mesio‐buccal aspects of two teeth. GCF IL‐6, IL‐1β, OSM, LIF, and IL‐11 levels were analyzed by enzyme‐linked immunosorbent assay. Results: The GO+ and GO? groups had higher IL‐6 total amounts than the healthy group (P <0.008). IL‐1β total amounts in the GO+ group were significantly higher than in both the healthy and GO? groups (P <0.008). OSM total amount was elevated in the GO+ and GO? groups compared with both the gingivitis and healthy groups (P <0.008). All groups had similar LIF and IL‐11 total amounts (P >0.008). Moderate positive correlations were detected among IL‐6, IL‐1β, OSM, and IL‐11 total amount in GCF and clinical parameters (P <0.05). Conclusions: IL‐6 and OSM increases in GCF as a result of CsA usage or an immunosuppressed state irrespective of the severity of inflammation and the presence of GO. The IL‐6 family of cytokines might not be directly involved in biologic mechanisms associated with CsA‐induced GO. Lack of an association between assessed IL‐6 cytokines and CsA‐induced GO might indicate distinct effects of these cytokines on fibrotic changes of different tissues.     

TNF-alpha TGF-beta2 and IL-1beta levels in gingival and peri-implant crevicular fluid before and after de novo plaque accumulation

Aims: The aim of this split‐mouth study was to investigate levels of tumour necrosis factor alpha (TNF‐α), transforming growth factor beta (TGF‐β2) and interleukin‐1 beta (IL‐1β) in gingival crevicular fluid (GCF) and peri‐implant crevicular fluid (PICF) after a 21‐day‐period of de novo plaque accumulation in the same patient. Material and Methods: In 25 patients, samples of GCF and PICF were collected in the sulcus of the tooth and of the implant after professional hygiene. After the no‐hygiene phase (21 days), second samples of GCF and PICF were taken. Third samples were collected after 69 days of re‐establishment oral hygiene techniques. The crevicular fluids were used to determine the volume and the levels of TNF‐α, TGF‐β2 and IL‐1β. Results: The volume of the crevicular fluids increased significantly after 21 days of plaque accumulation around teeth and implants and decreased significantly by 69 days. TNF‐α and TGF‐β2 did not change significantly among the three different samples. A significant increase of IL‐1β was observed after plaque accumulation around the teeth GCF, whereas in the PICF the increase was not statistically significant. Conclusions: These data suggest that increased volumes of GCF and PICF could be useful markers of early inflammation in gingival and peri‐implant tissues. In the presence of de novo plaque, implants showed lower, and nearly significant, levels of IL‐1β compared with teeth.