Background: The respiratory system is one of the main entrance gates for infection. The aim of this work was to compare the appearance of specific mucosal pro-inflammatory and common anti-microbial defence factors in healthy lung tissue, from an ontogenetic point of view. Materials and methods: Healthy lung tissues were collected from 15 patients (three females and 12 males) in the age range from 18 to 86. Immunohistochemistry to human β defensin 2 (HBD-2), human β defensin 3 (HBD-3), human β defensin 4 (HBD-4), cathelicidine (LL-37) and interleukine 17A (IL-17A) were performed. Results: The lung tissue material contained bronchial and lung parenchyma material in which no histological changes, connected with the inflammatory process, were detected. During the study, various statistically significant differences were detected in immunoreactive expression between different factors in all lung tissue structures. Conclusion: All healthy lung structures, but especially the cartilage, alveolar epithelium and the alveolar macrophages, are the main locations for the baseline synthesis of antimicrobial proteins and IL-17A. Cartilage shows high functional plasticity of this structure, including significant antimicrobial activity and participation in local lung protection response. Interrelated changes between antimicrobial proteins in different tissue confirm baseline synergistical cooperation of all these factors in healthy lung host defence.

Rosacea is a chronic inflammatory skin disease mainly affecting the facial skin. Our aim was to determine the appearance of pro- and anti- inflammatory cytokines in rosacea-affected facial tissue. Materials and Methods: Rosacea tissue were obtained from eight patients (aged 35 to 50 years). The control group (CG) included four facial skin samples (49 to 70 years). Routine staining and immunohistochemistry for IL-1, IL-10, LL-37, HBD-2, and HBD-4 proceeded. Results: Inflammation was observed in all the rosacea samples. A statistically significant difference was seen between epithelial HBD-2 positive cells in comparison to the control. There was a strong positive correlation between HBD-4 in the epithelium and HBD-4 in the connective tissue, IL-10 in the epithelium and IL-1 in the connective tissue, and IL-1 in the epithelium and IL-10 in the connective tissue. Conclusion: Increased levels of IL-10 and decreased levels of IL-1 show the balance between anti- and pro-inflammatory tissue responses. A significant amount of HBD-2 in the epithelium proves its important role in the local immune response of rosacea-affected tissue. The last effect seems to be intensified by the elevated level of LL-37 in the epithelium.

Background: The normal tissue structure of the respiratory system is necessary to provide adequate protection of the airways and lungs. Prolonged exposure to trigger factors can result in adaptive mechanism activation and lead to the development of chronic pulmonary diseases or even dysplastic changes. Materials and methods: Respiratory system material with a pseudostratified ciliated epithelium was obtained from 12 patients (aged 16 to 95), and material with a stratified squamosa epithelium was obtained from six patients (aged 23 to 93). Routine staining was performed, and an immunohistochemistry was conducted for MUC-2, MUC-6, NAPE-PLD, IL-6 and IL-13. Results: Inflammatory processes were not detected in any of the specimens. A number of correlations were identified, with the most important being a strong positive correlation for IL-13 between the alveolar epithelium and alveolar macrophages and a strong positive correlation for IL-6 between the alveolar epithelium and alveolar macrophages in the stratified squamous epithelium group. We also detected a statistically significant difference in IL-6 in alveolar macrophages. Conclusion: There were no signs of dysplastic changes in either group. Increased secretion of IL-13 in the stratified squamous epithelium group shows its involvement in metaplastic changes in the bronchial epithelium. The secretion of atypical factors by hyaline cartilage demonstrates its plasticity and adaptability.