Ex vivo study of IL-6 expression and function in immune cell subsets from human periapical lesions

Effects of Nd: YAG laser on tumour necrosis factor-alpha, interleukin-1beta and interferon-gamma levels in teeth with apical periodontitis: A clinical study

This study aimed to evaluate the levels of tumour necrosis factor-alpha (TNF-α), interleukin-1beta (IL-1β) and interferon-gamma (IFN-γ) with asymptomatic apical periodontitis (AP). A total of 60 participants were randomly divided into two groups: the conventional irrigation (control) and the Nd: YAG laser irradiation. The interstitial fluids were obtained after root canal cleaning (day 0) and 1 week later (day 7). The TNF-α, IL-1β and IFN-γ levels were assayed using the enzyme-linked immunosorbent assay. The Mann-Whitney U, continuity correction chi-square, Pearson chi-square and Fisher exact tests were used. An increased level of cytokines on day 7 in the control group was observed, without statistically significant differences (p > 0.05). All cytokine levels decreased over time in the laser group. Only the IL-1β level showed a significant difference (p < 0.05). Nd: YAG irradiation has a positive effect on decreasing the proinflammatory cytokine level and may help to control infection in teeth with AP.

Myeloid-derived suppressor cells in the therapy of autoimmune diseases

Myeloid-derived suppressor cells (MDSCs) are well recognized as critical factors in the pathology of tumors. However, their roles in autoimmune diseases are still unclear, which hampers the development of efficient immunotherapies. The role of different MDSCs subsets in multiple sclerosis, inflammatory bowel diseases, rheumatoid arthritis, type 1 diabetes, and systemic lupus erythematosus displayed different mechanisms of immune suppression, and several studies pointed to MDSCs' capacity to induce T-helper (Th)17 cells and tissue damage. These results also suggested that MDSCs could be present in different functional states and utilize different mechanisms for controlling the activity of T and B cells. Therefore, various therapeutic strategies should be employed to restore homeostasis in autoimmune diseases. The therapies harnessing MDSCs could be designed either as cell therapy or rely on the expansion and activation of MDSCs in vivo, or their depletion. Cumulatively, MDSCs are inevitable players in autoimmunity, and rational approaches in developing therapies are required to avoid the adverse effects of MDSCs and harness their suppressive mechanisms to improve the overall efficacy of autoimmunity therapy.

Periodontal Disease in Young Adults as a Risk Factor for Subclinical Atherosclerosis: A Clinical, Biochemical and Immunological Study

Although a strong relationship between periodontal disease (PD) and atherosclerosis was shown in adults, little data are published in younger PD patients. Therefore, this study aimed to investigate and correlate clinical parameters of PD, pro- and immunoregulatory cytokines in gingival crevicular fluid (GCF) and serum, biochemical and hematological parameters associated with atherosclerosis risk, and carotid intima-media thickness (IMT) in our younger study participants (n = 78) (mean age 35.92 ± 3.36 years) who were divided into two equal groups: subjects with and without PD. PD patients had higher values of IMT, hs-CRP, triglycerides, total cholesterol, and LDL; most proinflammatory and Th1/Th17-associated cytokines in GCF; and IL-8, IL-12, IL-18, and IL-17A in serum compared to subjects without PD. These cytokines in GCF positively correlated with most clinical periodontal parameters. Clinical periodontal parameters, TNF-α and IL-8 in GCF and IL-17A, hs-CRP, and LDL in serum, had more significant predictive roles in developing subclinical atherosclerosis (IMT ≥ 0.75 mm) in comparison with other cytokines, fibrinogen, and other lipid status parameters. Hs-CRP correlated better with the proinflammatory cytokines than the parameters of lipid status. Except for serum IL-17A, there was no significant association of clinical and immunological PD parameters with lipid status. Overall, these results suggest that dyslipidemia and PD status seem to be independent risk factors for subclinical atherosclerosis in our younger PD population.

Macrophages in periapical lesions: Potential roles and future directions

Periapical lesions are infectious diseases that occur in the apical region of teeth. They result in the destruction of alveolar bone and are usually accompanied by swelling, pain, and possible systemic impacts. A complex interaction between pathogens and the host immune system determines the development, progression, and outcome of periapical lesions. The lesions, if not treated promptly, may cause resorption of bone tissue, destruction of the periodontal ligament, and loss of the affected teeth, all of which can severely worsen the quality of life of patients, often at considerable economic cost to both patients and medical organizations. Macrophages are a group of heterogeneous cells that have many roles in the development of infections, destruction and reconstruction of bone tissues, and microbe–host interactions. However, the differential and comprehensive polarization of macrophages complicates the understanding of the regulatory mechanism of periapical lesion progression. This report provides a comprehensive review of recent advances in our knowledge of the potential role of macrophages in determining the turnover of human periapical lesions. For example, macrophage differentiation might indicate whether the lesions are stable or progressing while the extent of bacteria invasion could regulate the differentiation and function of macrophages involved in the periapical lesion. In addition, alternative strategies for the treatment of apical periodontitis are discussed.