Specific inhalation challenge with flour induced release of brain-derived neurotrophic factor in nasal fluid

Ciliated Cells Express a Novel Pattern of Brain-Derived Neurotrophic Factor in Allergic Rhinitis

Background

Mounting research indicates that brain-derived neurotrophic factor (BDNF), has great potential to increase neuro-hyperresponsiveness and airway resistance in airway allergic disease. The expression level of BDNF has been found to be notably elevated in lung/nasal lavage (NAL) fluid. However, the expression and position of BDNF in ciliated cells with allergic rhinitis remains unclear.

Methods

Nasal mucosal cells were collected from patients with allergic rhinitis (AR) and mice which were performed under different allergen challenge time, then observed the expression and position of BDNF located in ciliated cells through the immunofluorescence staining. Nasal mucosa, serum and NAL fluid were collected also. The expression level of BDNF and IL-4/5/13 were detected by RT-PCR. The expressions of BDNF (in serum and NAL fluid), and total-IgE, ovalbumin sIgE (in serum) were detected by ELISA.

Results

We found that MFI of BDNF in AR group's ciliated cells was obviously lower than that in the control group, and a negative correlation was discovered between MFI and VAS score. It can be roughly divided into 5 patterns according to its location in the cytoplasm of ciliated cells. In the mouse model, the expressions of BDNF in serum and NAL fluid increased temporarily after allergen stimulation. The MFI of BDNF in ciliated cells displayed an initial increase followed by a subsequent decrease.

Conclusion

Our study shows for the first time that, the expression and localization of BNDF were observed in the human nasal ciliated epithelial cells of allergic rhinitis, and the expression of level was less than the control group under the persistent state of allergy. BDNF expression in ciliated cells was transient increased after allergen stimulation and decreased to normal level after 24h in mouse model of allergic rhinitis. This might be the possible source of the transient increase of BNDF in serum and NAL fluid.

Local allergic rhinitis: mechanisms, diagnosis and relevance for occupational rhinitis

PURPOSE OF REVIEW

Local allergic rhinitis (LAR) is a new form of allergic rhinitis that has caused a growing interest. The possibility of an occupational equivalent (occupational rhinitis) has not been yet explored. The purpose of this review is to summarize the most relevant and recent scientific evidence on LAR and occupational rhinitis.

RECENT FINDINGS

LAR is a prevalent entity well differentiated from allergic rhinitis, affecting patients from different countries, ethnic groups and ages. Occupational rhinitis appears earlier and more frequently than occupational asthma, especially for high molecular weight substances. Diagnosis of LAR is based on nasal allergen provocation test and/or detection of nasal specific IgE, and other techniques such as basophil activation test may support the diagnosis. Skin prick tests and immunological determinations are of limited use for diagnosis of occupational rhinitis caused by low molecular weight agents. Performance of nasal allergen provocation test for confirming diagnosis of occupational rhinitis is strongly recommended. Uncommon allergens should also be investigated.

SUMMARY

The possibility of a local occupational rhinitis should be considered in workers with a clear history of occupational rhinitis and negative immunological test, especially in the case of high molecular weight allergens.