Detection of SARS-CoV-2 IgG antibodies and inflammatory cytokines in saliva-a pilot study

Novel Perspective on the Plasticity of Taste Perception: Is Food- and Exercise-Induced Inflammation Associated with Sweet Taste Sensitivity and Preference?

Obesity-related inflammation has been linked to decreased taste sensitivity and changes in the transcriptome of the taste apparatus. Increased levels of pro-inflammatory cytokines can also be found to be food-associated in individuals who consume high amounts of long-chain saturated fatty acids and sucrose independent of the body composition or individuals who exercise intensively. Previous research suggests a link between taste sensitivity and food choices. However, the interplay between food- or exercise-induced low-grade inflammation, taste perception, and food choices remains unaddressed. Understanding this relationship could provide an unnoticed explanation for interindividual differences in taste perception that influences dietary habits.

Impact of social distancing from the COVID-19 pandemic on the immuno-inflammatory response of older adults

BACKGROUND

Older adults, as the population considered at increased risk for severe COVID-19, were the most impacted by social isolation. Thus, this study aimed to assess the salivary immune/inflammatory response of older adults before and during the COVID-19 pandemic.

METHODS

A cohort of 11 older adults (mean age 66.8 ± 6.1) was followed at three different time points: before (S1) and after 6 (S2) and 20 months (S3) of the beginning of the COVID-19 pandemic in Brazil. Unstimulated saliva samples were obtained to assess the levels of antibodies (secretory IgA, IgG and IgM) by ELISA and cytokines (IL-2, IL-5, IL-6, IL-8 and IL-10, TSLP, IFN-γ, TNF-α) by multiplex analysis. Significant differences were evaluated using the Kruskal-Wallis test with Dunn's post-test.

RESULTS

None volunteer presented periodontal disease or caries. All volunteers received at least two doses of the COVID-19 vaccines after S2 and before S3. A tendency to increase salivary levels of SIgA and IgM at S2 and of IgG at S3 were observed compared to the values found at S1 and S2. Significantly decreased levels of IL-2 and IL-5 were found at S2 and S3 (p < 0.001) time points. Lower levels of IFN-γ were found at S2 as compared to the values observed at S1 (p < 0.01). A significant decrease in the IFN-γ/IL-10 ratio was found at S2 (p < 0.01). When assessing the Th1/Th2 ratios, a significant decrease was found in the IFN-γ/TSLP ratio at S2 (p < 0.001) and S3 (p < 0.001) when compared to the values at S1. In addition, a significant increase was observed in the TNF-α/IL-5 ratio at S2 (p < 0.001) and S3 (p < 0.001) in comparison to the values at S1. In a similar way, an increase in the TNF-α/IL-6 ratio (Fig. 5E) was observed at S3 (p < 0.001) when compared to the values at S1.

CONCLUSIONS

Overall, this study provides valuable insights into the impact of COVID-19-induced social isolation on immune/inflammatory responses in the upper airway mucosa, particularly those present in oral cavity, of older adults. It demonstrates that a controlled shift in Th1 and Th2 immune responses, both during infection and post-vaccination, can create favorable conditions to combat viral infections without exacerbating the immune response or worsening the pathology.

Convergence of inflammatory response: Salivary cytokine dynamics in coronavirus disease 2019 and periodontal disease

Background

Periodontal disease is associated with immune dysregulation, and cytokines released can add on to the coronavirus disease 2019 (COVID-19)-associated cytokine storm, further worsening the related adverse outcomes. Specific studies investigating cytokine levels in COVID-19 patients with periodontal disease are lacking. Examining the correlation between these conditions could aid in categorizing risk categories, determining referrals, and strengthening oral hygiene protocols. The current study sought to evaluate cytokine levels in the saliva of COVID-19-positive patients with and without periodontal disease.

Materials and Methods

Twenty-six COVID-19-positive patients were subjected to periodontal examination, saliva collection, and assessment of cytokine levels through cytokine bead-based multiplex assay, using fluorescence-encoded beads with flow cytometry (BD FACS LSRFortessa). Eleven cytokines were assessed (interleukin [IL] 2, 4, 6, 10, 17A, and interferon-gamma (IFN-gamma), tumor necrosis factor-alpha (TNF-α), chemokine ligand 2 (CCL2/monocyte chemoattractant protein-1), C-X-C motif chemokine ligand (CXCL) 8/IL 8, CXCL 9/monokine-induced gamma interferon [MIG]), and CXCL 10 (chemokine IFN-gamma inducible protein 10 kDa). The cytokine levels of the recruited subjects were also compared graphically with the salivary cytokine levels reported in the literature for health, COVID-19, and periodontal disease alone.

Results

Out of 26 COVID-19-positive patients, 17 had periodontal disease. Levels of all cytokines were raised in patients with both diseases when compared to values reported in literature for health, periodontal disease alone, or COVID-19 alone. However, there was no statistical difference among the recruited subjects for IL-2, IL-4, IL-6, IL-10, IL-17A, IFN-gamma, TNF-α, CCL2, CXCL 8, and CXCL 10. MIG levels were found to be higher in periodontally healthy, COVID-19-positive subjects (P = 0.01).

Conclusions

Periodontal disease might contribute to the COVID-19-induced cytokine storm, potentially amplifying its impact.