Serum and nasal lavage fluid Clara cell protein decreases in children with allergic rhinitis

Development of an effective sample transfer device for biomarker detection in nasal secretions

Nasal secretions (NS) reflect inflammatory activity of the nasal mucosa and thus can be utilized for disease diagnosis and determining treatment effects in Allergic rhinitis (AR). However, non-standardized collection of samples can affect the measured concentration of inflammatory biomarker in NS. In this study, we aimed to develop and evaluate new devices capable of standardizing the collection, storage, and preprocessing methods of NS samples. First, we chose the best swab as polyester (PE) and selected a stimulation method, twirling for 10 s at 1 Hz, to efficiently release AR biomarkers from a PE swab. Storage of sample solutions at -20 °C was optimal for the stability of biomarkers for the detection of AR. The new swab sample transfer device showed excellent concentration recovery efficiency (90-100%) for tryptase (Trp) and eosinophil cationic protein (ECP) without crosstalk between the two biomarkers. Finally, we compared the concentration of Trp in human NS samples of AR patients (n = 6) pre-processed by the new device with that by centrifuge as a standard method. As a result, the concentrations of Trp in NS were very similar in both groups. Therefore, this device can be utilized as an effective sample transfer and pre-processing device for point-of-care testing of AR.

Eosinophil Chemokines and Clara Cell Protein 16 Production in Nasal Mucosa of Patients with Persistent Allergic Rhinitis

Objective

Eotaxin-2 and regulated on activation normal T cell expressed and secreted (RANTES) are involved in the eosinophil trafficking in patients with persistent allergic rhinitis (PAR). Clara cell protein 16 (CC16) is an anti-inflammatory protein mainly produced by the epithelial non-ciliated Clara cells. The aim of this study was to investigate the production of CC16 and chemokines eotaxin-2 and RANTES in nasal mucosa of patients with PAR.

Materials and Methods

Twenty-one PAR patients and 20 healthy participants were included. CC16, eotaxin-2, and RANTES concentrations were measured in nasal secretions. PAR patients were administered fluticasone furoate nasal spray (220 μg daily for 14 days). We performed nasal cytology, symptom score assessment, and inflammatory mediator detection before and after the therapy.

Results

The level of CC16 in patients with PAR was lower than in the healthy subjects (p=0.023). The eosinophil counts and local concentrations of eotaxin-2 and RANTES were higher in patients with PAR in comparison with controls (p=0.008, p=0.001, p=0.031, respectively). We also found a negative correlation between the CC16 and eotaxin-2 levels in nasal secretions of PAR patients (r=-0.492, p=0.023). After corticosteroid therapy, the patients with PAR had lower nasal symptoms, eosinophil counts, eotaxin-2, and RANTES levels and higher levels of CC16 (p<0.001 for all parameters).

Conclusion

Our results suggest the presence of a negative correlation in production of CC16 and eotaxin-2 in nasal mucosa of patients with PAR. Intranasal corticosteroids have a suppressive effect on mucosal eosinophilic inflammation and a stimulating effect on local CC16 production.

Beyond anti-microbial properties: The role of cathelicidin in allergic rhinitis

BACKGROUND

Cathelicidin, an anti-microbial peptide, is a component of the innate immune system. Cathelicidin has anti-microbial, anti-inflammatory and immunoregulatory functions. Knowledge about the role of the innate immune system in the pathogenesis of allergic diseases has expanded in recent years. We measured levels of the LL-37 peptide in the nasal fluids of children with allergic rhinitis (AR) and investigated the possible role of this peptide in the pathogenesis of AR.

METHODS

The study population included 46 children who were newly diagnosed with AR and not taking any medication. Thirty-three healthy control subjects were also enrolled. Nasal secretions were collected from the study and control groups using a polyurethane sponge nasal secretion collector, and nasal fluid LL-37 levels were determined using the ELISA method.

RESULTS

The levels of LL-37 in the nasal fluid of the AR patients were lower than those of the control group (median of 2.3ng/ml [minimum-maximum, 2.1-3.2] vs. 2.6ng/ml [2.1-5.4], respectively; p<0.001), and they were significantly reduced in patients with moderate/severe AR compared with those of patients with mild AR (2.2ng/ml [2.1-2.4] vs. 2.5ng/ml [2.1-3.1], respectively; p<0.001).

CONCLUSION

Our results show that children with AR have reduced nasal fluid LL-37 levels compared with healthy controls. Additionally, children with moderate/severe AR have decreased nasal fluid LL-37 levels compared with children with mild AR. These findings highlight the role of cathelicidin in the pathogenesis of AR.