Human nasal epithelium and cellular elements in chronic allergic rhinitis. Electron-microscopic study

Effects of passive smoking on adult nasal respiratory mucosa

OBJECTIVE

The present study aimed to investigate nasal mucosal changes in response to passive exposure to cigarette smoke.

STUDY DESIGN

The study included 20 women aged 35-51 years who were scheduled for non-rhinological surgical procedures, and who had at least 10 years' prolonged passive exposure to household cigarette smoke. During surgery, two 1-mm3 biopsies of nasal mucosa were taken from the lower border of the inferior turbinate. Specimens were processed and examined with light and transmission electron microscopy.

RESULTS

Examination of the nasal mucosa showed several histopathological changes. The severity of structural changes increased with duration of smoke exposure. No allergic or neoplastic changes were seen.

CONCLUSION

Passive exposure to cigarette smoke has a deleterious effect on the nasal respiratory mucosa. Prolonged passive smoke exposure may also induce other, significant changes not detected in the present study.

Expression of epidermal growth factors and a tight junction protein in the nasal mucosa of patients with chronic hypertrophic rhinitis

BACKGROUND

ErbB family receptors and tight junction proteins participate in the pathologic process including tissue remodelling of inflammatory diseases in the upper and lower respiratory tracts. This study aimed at investigating the expressions of erbB1, 2, 3, 4, and a tight junction protein, claudin-1, in the nasal mucosa of patients with chronic hypertrophic rhinitis.

METHODS

Inferior turbinates were collected from 10 turbinectomised patients with allergic and non-allergic chronic hypertrophic rhinitis. The expressions of erbB1, 2, 3, 4, and claudin-1 were examined by fluorescence immunohistochemistry and by quantitative real-time transcription-polymerase chain reaction (qRT-PCR).

RESULTS

All erbB1-4 and claudin-1 were detected, and mainly localised in the epithelial cells and nasal gland cells. The immunoreactivity for claudin-1 was positively correlated with the expressions of erbB1, 2 and 4, but negatively correlated with that of erbB3. The mRNA expressions of erbB1, 2 and 4 were positively correlated with one another, whereas the expression of erbB3 showed negative correlation with the immunoreactivity for erbB2 and 4.

CONCLUSIONS

These results suggest a possible participation of erbBs and claudin-1 in tissue remodelling in chronic hypertrophic rhinitis.

Synergism of Staphylococcus aureus colonization and allergic reaction in the nasal cavity in mice

BACKGROUND

The aim of this study is to investigate the reciprocal effect of Staphylococcus aureus colonization and allergic rhinitis in an allergy model of mice.

METHODS

BALB/c mice with intraperitoneal ovalbumin (OVA) sensitization and/or intranasal S. aureus inoculation were prepared. The following 4 groups were designed: an OVA-sensitized S. aureus-inoculated (AR-SA) group, an OVA-sensitized uninoculated (AR) group, a nonsensitized S. aureus-inoculated (SA) group, and a nonsensitized uninoculated (control) group. After intranasal OVA challenge, nasal lavage fluid, peripheral blood, and nasal mucosa were collected. Polymorphonuclear cells in the nasal lavage fluid were counted, serum OVA-specific IgE and IgG1 were measured by enzyme immunoassays, and IL-4, IL-5, and IFN-γ mRNAs in the nasal mucosa were assessed by quantitative real-time reverse transcription-PCR. The number of S. aureus in the nasal mucosa and lavage fluid was counted.

RESULTS

Both eosinophil and neutrophil counts were larger in the AR-SA group than in the other groups. Both IgE and IgG1 levels were higher in the AR and AR-SA groups than in the SA and control groups, and the IgG1 level was higher in the AR-SA group than in the AR group. The expression of IL-4 mRNA was higher in the AR-SA group than in the other groups, and the expression of IL-5 mRNA was higher in the AR-SA group than in the SA group. The AR-SA group showed higher counts of S. aureus in the nasal mucosa than the SA group.

CONCLUSION

These results indicate the mutually potentiating effect of S. aureus colonization and allergic rhinitis.

Effect of passive smoking on the ultrastructure of the nasal mucosa in children

OBJECTIVES/HYPOTHESIS

Passive exposure to cigarette smoke has been implicated in a number of respiratory childhood disorders. Most studies concerning smoking were directed to its carcinogenic effect on the lungs. However, the effects of smoking on nasal respiratory mucosa have not been widely studied. The aim of the present study was, therefore, to study the ultrastructural changes in the nasal mucosa of a pediatric population exposed to passive smoking.

STUDY DESIGN

The study included 20 children between the ages of 5 and 11 years, who were scheduled for tonsillectomy and at the same time had a positive history of prolonged exposure to household passive smoke. Another 10 children with a negative household smoking history were included as a control group. All children were nonatopic and with a negative family history of allergy. None of them had adenoids or infective rhinosinusitis.

METHODS

At the time of surgery, a 1-mm(3) biopsy was taken was taken from the lower border of the inferior turbinate. The specimens were processed and examined with electron microscopy

RESULTS

Examination of the nasal mucosa showed several ultrastructural changes. These included patchy loss of cilia, generalized loss of cilia, squamous metaplasia, hyperplasia of goblet cells and seromucinous acini, and vascular congestion. More severe changes were observed with longer passive exposures to cigarette smoke. The study did not disclose any evidence of ongoing allergic reaction or neoplastic transformations.

CONCLUSIONS

Children exposed to passive cigarette smoke may develop several structural changes in the respiratory nasal mucosa with subsequent negative effects on its ciliary activity and mucociliary function. As a result of these effects, defense mechanisms of the nose may be ruined or lost, and those children may develop persistent sinonasal infections. Exposure of these children to passive smoking for longer periods of time may also induce other significant changes that were not detected in the present study.

Enhancement of submicroscopic damage of the nasal epithelium by topical allergen challenge in patients with perennial nasal allergy

The purposes of this study were to clarify whether damage of the nasal epithelium exists in patients with nasal allergy, and how the morphology of the epithelium changes after topical allergen challenge. Electron microscopy revealed 2 characteristic features in the nasal epithelium of patients with perennial nasal allergy--an increase in the number of epithelial cells with cytoplasmic vacuoles, and markedly widened intercellular spaces--although these changes were unclear under light microscopy. The density of vacuolated cells significantly increased 24 hours after allergen challenge. Further, the number of eosinophils that were associated with vacuolated cells was significantly higher in patients with nasal allergy than in controls. These morphological changes, thus, were considered to be types of damage to the nasal epithelium associated with nasal allergy. Such changes may be among the causes of nasal hyperreactivity, which is an important feature of nasal allergy.

Time course of changes in absorption of macromolecule through the nasal mucosa after antigen challenge in guinea pig model of allergic rhinitis

The time course of changes in absorption of horseradish peroxidase (HRP) through the nasal mucosa after antigen challenge was evaluated in a guinea pig model of allergic rhinitis immunized with ovalbumin. Before and at 5 minutes, 4 hours, and 24 hours after nasal antigen challenge, both nasal cavities were filled with 5% HRP solution for 30 minutes, and blood was obtained to measure serum HRP levels by enzyme-linked immunosorbent assay. In immunized animals, the serum HRP levels were 2.3 times higher than those of normal controls (p<.05) before antigen challenge, which was performed 7 days after a series of nasal antigenic sensitizations. At 5 to 35 minutes after antigen challenge, the HRP levels decreased to one sixth of the prechallenge levels (p<.05), and they did not show a difference from the control levels. However, they increased markedly at 4 and 24 hours after antigen challenge (p<.01). The present study suggests that the absorption of macromolecules through the allergic nasal mucosa is enhanced markedly, depending upon the time course after antigen challenge, although it shows no apparent difference from normal controls during the dominant exudative process.

Transepithelial migration of activated eosinophils induces a decrease of E-cadherin expression in cultured human nasal epithelial cells

BACKGROUND

The damage of respiratory epithelium in allergic diseases has a close correlation with the extent of eosinophil infiltration. It seems to be a good possibility that eosinophil infiltration could induce the changes in the expression of the epithelial cell adhesion molecules, which play a key role in the maintenance of structural and functional rigidity of epithelium.

OBJECTIVE

We observed the expression of E-cadherin in cultured human nasal epithelial cells (HNECs) to study whether could it be affected by transepithelial migration of inflammatory cells, especially eosinophils.

METHODS

In vitro study of the transmigration assay was designed using various types of inflammatory cells and HNEC monolayers. Various assays of each experimental group were done under the stimulation of interleukin-5 (IL-5) and/or platelet activating factor (PAF). Subsequently immunohistochemistry for E-cadherin was performed in the HNECs. The intensity of immunofluorescence of E-cadherin was quantified using confocal laser scanning microscopy (CLSM) system and compared before and after the transmigration.

RESULTS

The mean intensity of immunofluorescence for E-cadherin decreased significantly after the transmigration of any types of inflammatory cells. Above all, the migration of eosinophils treated with IL-5 and PAF had an eminent effect on the decrease, whereas the degranulation extracts derived from eosinophils activated by IL-5 and secretory IgA (sIgA) did not affect the intensity.

CONCLUSION

This work suggests that transepithelial migration of inflammatory cells can directly induce the decrease in epithelial E-cadherin expression. Furthermore, the most prominent change was induced by transmigration of activated eosinophils, which might be caused by some mechanisms independent of the eosinophil contents. The decrease in E-cadherin expression may trigger the damage of epithelial barrier, which contributes to the pathogenesis of allergic diseases.

Topical levocabastine for the treatment of perennial allergic rhinitis

The ultrastructure of the nasal mucosa following the use of intranasal levocabastine was studied in 20 patients suffering from perennial allergic rhinitis. The patients received twice daily 0.05 per cent levocabastine spray with a treatment duration of four weeks. At the end of the treatment period regression of the allergic process was evidenced by progressive reappearance of normal cilia and microvilli on the columnar cells, decrease of intercellular oedema and cytoplasmic vacuoles, increased number of mucous acinar cells, gradual decrease of vascular congestion, as well as diminished oedema fluid formation. The drug, however, had no effect on mast cell degranulation nor on eosinophilic infiltration. Normalization of the ultrastructural features correlated well with clinical improvement. Considering the results of the present study, levocabastine nasal spray appears to be an effective treatment for perennial allergic rhinitis and can be used with, or as an alternative to, other anti-allergic medications.

The human respiratory nasal mucosa in pregnancy. An electron microscopic and histochemical study

The ultrastructural and histochemical changes in the respiratory nasal mucosa of thirty pregnant females have been studied. Symptoms-free pregnant females, regardless of the duration of pregnancy, showed glandular hyperactivity, increased phagocytic activity, and increased amount of acid mucopolysaccharides in the ground substance. These changes have been suggested to be due to the rise in the levels of female sex hormones during pregnancy. Pregnant females developing nasal symptoms during pregnancy have been proved by electron microscopy and histochemically to be allergic in origin. This allergy, being not due to the hypersensitization of the patient's own sex hormones, may be due to any of the factors previously mentioned.