Relationship between histologic changes and inflammatory markers in chronic rhinosinusitis

The present study aimed to elucidate the relationship between histologic changes and inflammatory markers in chronic rhinosinusitis (CRS). Inflammatory markers of CRS, including eosinophil and neutrophil counts, the eosinophil-to-lymphocyte ratio, and the neutrophil-to-lymphocyte ratio, were investigated in tissues and peripheral blood. Inflammatory markers were evaluated according to the histologic changes of stromal edema, stromal fibrosis, and basement membrane (BM) thickening. Among 92 patients with CRS who underwent pathologic examinations, stromal edema, stromal fibrosis, and BM thickening were identified in 84.8%, 25.0%, and 53.3% of patients, respectively. Stromal edema and BM thickening were observed more frequently in CRS with nasal polyps than in CRS without nasal polyps (P = 0.001 and P = 0.001, respectively). Tissue inflammatory markers differed according to the presence of histologic changes in tissues. In peripheral blood, however, only the eosinophil count differed according to BM thickening. Patients with two or more histologic changes had higher tissue eosinophil-to-lymphocyte ratios (P = 0.008) and eosinophil counts (P = 0.002) compared with subjects with no or one histologic change. Conversely, the tissue neutrophil-to-lymphocyte ratio and neutrophil count were higher in patients with no or one histologic change than in patients with two or more changes. Collectively, tissue inflammatory markers may be correlated with histologic changes in CRS. However, serum inflammatory markers have a limited ability to predict histologic changes in patients with CRS.

Histology-based profile of inflammatory mediators in experimentally induced pulpitis in a rat model: screening for possible biomarkers

Aim

To profile molecular changes in lipopolysaccharide (LPS)‐induced experimental pulpitis in a rat model and explore the feasibility of a molecular‐based diagnostic strategy for pulpitis.

Methodology

Seventy‐three maxillary incisors of Sprague‐Dawley rats were used to establish pulpitis models with LPS. Inflammatory grading was performed in four equal sections of the pulp divided from the injured site to the root apex. An antibody array was used to compare the expression of 67 molecules between control pulp and inflamed pulp 12 and 72 h after LPS application. The levels of differentially expressed molecules in the control and inflamed pulp (collected at 3, 6, 9, 12, 24 and 72 h after LPS treatment) were examined via ELISA, and correlations between inflammatory scores and molecule expression were assessed. The molecule distributions in the pulp were investigated by immunofluorescence staining. Data were analysed with paired t‐test, one‐way anova, Kruskal–Wallis tests, and Spearman’s and Pearson’s correlations with significance set at P < 0.05.

Results

Polymorphonuclear neutrophils were observed in the injured site 3 h after LPS stimulation. Inflammatory infiltration peaked at 12 h and was limited to the injured site with osteodentine deposition at 72 h. Thirteen molecules were significantly differentially expressed between the control and LPS‐injured pulp. ELISA validated that tissue inhibitor of metalloproteinase‐1 (TIMP‐1) expression dramatically peaked at 12 h (compared with other time points, P < 0.05) and returned to baseline at 72 h. The TIMP‐1 concentration was strongly correlated with inflammation severity in the apical three‐quarters of the pulp, and the strongest correlation was found in the lower‐middle quarter (r = 0.786, P < 0.001). Immunofluorescence staining revealed that in the apical three‐quarters of the pulp, TIMP‐1 expression was significantly higher in the 12 h group than in the control and 3, 6, 24 and 72 h groups (P < 0.01).

Conclusion

This study provides a molecular profile of LPS‐induced pulpitis in a rat model. TIMP‐1 had a strong positive correlation with the severity of dental pulp inflammation, verifying the feasibility of applying biomarkers to identify specific pathological conditions in pulpitis.