Immunoglobulins in nasal secretions of patients with allergic rhinitis and chronic rhinosinusitis

Nasal mucus proteome and its involvement in allergic rhinitis

Introduction: Nasal mucus is the first line defense barrier against various pathogens including allergens. Proteins in nasal mucus maybe used as biomarkers for diagnosis or future therapeutic strategies. Proteomics opens the possibility to investigate whole human proteomes.

Areas Covered: We aimed to analyze the existing literature on nasal mucus and nasal secretions proteomic approaches especially in allergic rhinitis. A PubMed/Medline search was conducted entering the following keywords and combinations: “nasal mucus”, “nasal lavage fluid,” nasal secretions,” “nasal swabs,” “allergic rhinitis,” ”proteins,” and “proteomics.”

Expert opinion: The majority of studies focus on single proteins or protein groups mainly using ELISA techniques. Four studies met the criteria using mass spectrometry in the analysis of nasal mucus proteomes in rhinologic diseases. In these studies, 7, 35, 267, and 430 proteins were identified, respectively. These four studies are discussed in this review and put in relation to seven other proteomic studies that focus on nasal lavage fluid and nasal secretions obtained by swabs or filter paper. To put it in a nutshell, proteomics facilitates the investigation of the nasal secretome and its role in healthy and diseased state and as potential biomarkers for new diagnostic or therapeutic approaches.

Effect of nasal antihistamine on secretory IgA in nasal lavage of rats

The humoral IgA is an immunoglobulin which plays a defensive role for organisms on mucosal surfaces. Today, intranasal antihistamines are effectively used in the treatment of allergic rhinitis. In our study, the effect of azelastine hydrochloride-a nasal antihistaminic-on humoral IgA of the nasal mucosa has been reviewed empirically. Twenty-four female Sprague-Dawley rats were included in our study. The rats were divided into three groups randomly. Group 1(azelastine hydrochloride): rats in this group had nasal azelastine hydrochloride (0.05%) applied for 30 days at 10 µl/nostril dosage. Group 2 (saline): saline (0.09%) was applied to the rats in this group for 30 days at 10 µl/nostril dosage. Group 3 (control): no application was made throughout the study. The chemicals applied in Groups 1 and 2 were applied to both nostrils by mounting a flexible micropipette to the end of an insulin injector. At the beginning of the study, nasal lavage was performed to both nostrils of the rats in every group on the 15th and 30th day to aspirate irrigation solution (distilled water). The aspirated liquids were kept at - 80° temperature and reviewed together at the end of study. Within-group comparisons: in Group 1 (azelastine hydrochloride), the humoral IgA value on the 15th day was significantly higher than the basal value (p = 0.037). There is a significant difference between humoral IgA value on the 30th day and humoral IgA value on the 15th day (p = 0.045). In Group 2 (saline), no significant difference is available between basal, 15th day and 30th day humoral IgA values (p = 0.265). In Group 3 (control), no significant difference is available between basal, 15th day and 30th day humoral IgA values (p = 0.374). Between-group comparison: there is no significant difference in between-group humoral IgA basal values (p = 0.714). On days 15 and 30, Humoral IgA value of Group 1 was significantly higher than that of Groups 2 and 3 (p = 0.013, p = 0.024, respectively). According to the results we achieved in our study, nasal antihistaminic (azelastine hydrochloride) significantly increases the level of humoral IgA. Our study is the first one in the literature to reveal a relation between nasal antihistaminic and humoral IgA and there is a further need for clinical, randomized and prospective studies.

Nasal fluid secretory immunoglobulin A levels in children with allergic rhinitis

OBJECTIVES

There is growing knowledge about the immunoregulatory and possibly preventative roles of immunoglobulin A (IgA) in allergic diseases. This study aimed to investigate secretory immunoglobulin A (SIgA) levels in the nasal fluid of children who were either being treated for their allergic rhinitis (AR) with intranasal mometasone furoate or were not receiving treatment.

METHODS

The study population contained 55 children with persistent AR. Group I included 27 newly diagnosed AR patients not taking any medication and group II included 28 patients treated with intranasal steroids for at least 6 months. 27 healthy control subjects were also enrolled in the study. Total symptom scores (TSS) were calculated for each patient. Nasal secretions were obtained using a new modified polyurethane sponge absorption method, and samples were analysed by ELISA.

RESULTS

The median value for nasal fluid SIgA level in each group was 127.2μg/ml (interquartile range; 67.3-149.6) in group I, 133.9μg/ml (102.1-177.8) in group II and 299.8μg/ml (144.5-414.0) in the control group. Groups I and II both had statistically significant reductions in nasal fluid SIgA levels compared to the control group (p<0.001). However, there was no statistically significant difference between groups I and II (p=0.35). A statistically significant and negative correlation also existed between TSS and nasal fluid SIgA levels in both groups I and II (p=0.006, rho=-0.512 and p=0.01, rho=-0.481, respectively).

CONCLUSIONS

SIgA levels in the nasal fluid are significantly reduced in children with AR independent of treatment and are negatively correlated with the TSS.

The role of allergy in rhinosinusitis

PURPOSE OF REVIEW

To examine the current evidence for IgE and non-IgE-mediated hypersensitivity mechanisms in acute and chronic rhinosinusitis.

RECENT FINDINGS

Epidemiological studies show that classical IgE-mediated allergy is present in a proportion of acute rhinosinusitis patients. There is conflicting evidence whether the prevalence of IgE-mediated allergy is greater in chronic rhinosinusitis than in individuals without chronic rhinosinusitis. Despite presence of classical IgE-mediated allergy, based on elevated allergen-specific serum IgE levels and positive skin prick tests, currently there is no direct evidence for allergy as a major cause of sinonasal inflammation in chronic rhinosinusitis. There is increasing evidence that non-IgE-mediated fungal hypersensitivity and nonallergic IgE-associated inflammation may contribute to the pathogenesis in some forms of chronic rhinosinusitis, including allergic fungal sinusitis. Specific IgE to bacterial superantigens may also be elevated in nasal polyps and modulate eosinophilic inflammation. Recent insights into mucosal immune mechanisms yield intriguing prospects for the roles of mucosal IgE, mast cells and non-IgE-mediated hypersensitivity mechanisms that require further examination in rhinosinusitis.

SUMMARY

There is a need for further immunological studies of the systemic and mucosal cellular and humoral mechanisms in well defined patient groups and controls to better understand the role of IgE and non-IgE-mediated hypersensitivity mechanisms and nonhypersensitivity functions of IgE in rhinosinusitis.