RESUMO
Background: /Purposes: Studies have indicated that salivary molecules from patients with periodontitis and diabetes are confounded with pathological conditions associated with SARS-CoV-2 infection. The study aimed to address whether the abundance of Porphyromonas gingivalis which causes periodontitis, differed compared with that of Aggregatibacter actinomycetemcomitans (used as control) and to analyze the correlation of periodontitis with the expression levels of severe acute respiratory syndrome coronavirus 2 receptor (ACE2) and periodontitis inflammatory markers (TLR-2/TLR-4, TNFα, and miR-155). Materials and Methods: A saliva sample (5 mL) was obtained from 23 hospitalized patients with COVID-19, categorized into two groups: diabetic (G1, n = 10) and non-diabetic (G2, n = 13). Saliva from patients with periodontitis without diabetes and coronavirus disease 2019 (COVID-19; n = 6) were included as control. The quantitative real-time polymerase chain reaction measured the levels of P. gingivalis and A. actinomycetemcomitans, as well as periodontitis markers in saliva. The obtained data were analyzed using one-way ANOVA and the Spearman correlation test. Results: The abundance of P. gingivalis was observed to be higher (p < 0.05) in saliva of patients with diabetes (G1) than in those without diabetes (G2). A contradictory trend was observed for A. actinomycetemcomitans. The transcription level of ACE2 was comparable in all groups tested, while the expression of periodontitis markers varied. The relationships and sensitivity/specificity among P. gingivalis infection ACE2 expression, and inflammatory markers were also evaluated. Conclusions: This study showed that the association between P. gingivalis infection and ACE2 expression might reflect the characteristics of saliva in COVID-19 patients with and without diabetes. However, the relationships between TLR-4 and miR-155 are more specific in discriminating against COVID-19 patients with and without diabetes.
RESUMO
Background: The available evidence suggests that inflammatory responses, in both systemic and oral tissue, contribute to the pathology of COVID-19 disease. Hence, studies of inflammation biomarkers in oral fluids, such as saliva, might be useful to better specify COVID-19 features. Methods: In the current study, we performed quantitative real-time PCR to measure salivary levels of C-reactive protein (CRP) and interleukin-6 (IL-6) in saliva obtained from patients diagnosed with mild COVID-19, in a diabetic group (DG; n = 10) and a non-diabetic group (NDG; n = 13). All participants were diagnosed with periodontitis, while six participants with periodontitis but not diagnosed with COVID-19 were included as controls. Results: We found increases in salivary total protein levels in both the DG and NDG compared to control patients. In both groups, salivary CRP and IL-6 levels were comparable. Additionally, the levels of salivary CRP were significantly correlated with total proteins, in which a strong and moderate positive correlation was found between DG and NDG, respectively. A linear positive correlation was also noted in the relationship between salivary IL-6 level and total proteins, but the correlation was not significant. Interestingly, the association between salivary CRP and IL-6 levels was positive. However, a moderately significant correlation was only found in COVID-19 patients with diabetes, through which the association was validated by a receiver operating curve. Conclusions: These finding suggest that salivary CRP and IL-6 are particularly relevant as potential non-invasive biomarker for predicting diabetes risk in mild cases of COVID-19 accompanied with periodontitis.
