## 3 Results
### Allergic Rhinities
#### 3.2.1 Diagnosis of Allergic Rhinitis
Allergic phenotypes of rhinitis are determined by measuring allergen-sIgE in serum and BAT [149]. BAT reproduces in vitro, after allergen exposure, the type I hypersensitivity reaction [150]; an immediate reaction that involves IgE-mediated release of antibodies against the soluble antigen [151]. For LAR diagnosis, BAT exhibits a high specificity (100%), in contrast to its sensibility (ranging from 50% to 66.6%) depending on the allergen evaluated [117; 152; 153]. In this regard, 37.5% of LAR individuals (all of them with NAC positive to _Dermatophagoides pteronyssinus_) and 60% of dual allergic rhinitis (DAR) patients showed positive BAT responses with perennial allergens, as opposed to NAR and healthy subjects (negative for all of them) [154]. Molecular Diagnostic Parameters in Allergic Rhinitis  
In the last few decades, several studies have focused on molecular parameters associated with inflammation in AR, such as chemokines associated with Th2 function [8]. In this context, high levels of CCL22 (monocyte-derived chemokine (MDC)), which promote selective migration of Th2 cells, were found in the serum of patients with AR sensitized to birch pollen [155] and ragweed pollen [156], suggesting a possible role in the pathogenesis of AR. Another chemokine that has been associated with AR is CCL13, whose expression is stimulated by IL-4 and was found to be increased in the serum of AR patients after NAC [157]. On the other hand, miRNAs are thought to be involved in the pathogenesis of AR [40; 158; 159]. MiR-155 levels in serum of children with pollen-induced AR were higher in comparison with healthy controls, and miR-155 in the serum correlated significantly with nasal symptoms in children with AR (r = 0.494, \(p\) < 0.001) [160]. Moreover, [PERSON] and colleagues found serum TSLP, expression of miR-375 from whole blood, and frequencies of ILC2 in peripheral blood levels significantly higher in AR children compared with controls [140]. Moreover, another study showed that the level expression of miR-487b was repressed in AR in comparison to control cases [161]. Finally, [PERSON] et al. found that the expression of miR-143 was significantly decreased in nasal mucosal tissues from AR patients compared with tissues from NAR subjects [162]. Additionally, Th1/Th17 were also proposed to be involved in allergic diseases, such as AR [163]. In this context, [PERSON] et al. [143] showed that serum and nasal IL-17 were higher in AR in comparison with control individuals. Moreover, [PERSON] and collaborators showed that serum levels of IL-8 were significantly higher in patients with allergic asthma in comparison with AR and controls, suggesting that IL-8 is associated with a more severe inflammatory response [164]. However, other studies showed that elevated levels of IL-8 can also be related to pollution and not only allergic sensitization, suggesting that air pollution might induce or aggravate AR through this cytokine [165]. Other studies, such as [PERSON] et al., showed a decreased surface CXC motif chemokine receptor 3 (CXCR3) expression in CD4+ T cells of AR patients [166]. In the case of the innate immune response, a study performed by [PERSON] (which excluded individuals with an active infection), with 205 AR patients and 49 healthy controls, found that the neutrophil/lymphocyte ratio was significantly lower in patients with AR than in healthy controls [167]. In relation to ILC2, several studies showed that these cells in peripheral blood and nasal samples are increased after NAC, and there was also a positive correlation between eosinophils and IL-5 concentrations in patients with AR [168; 169]. In this context, several studies showed evidence of increased epithelial proinflammatory cytokines, such as IL-25, IL-33, and TSLP in the nasal lavage from patients with house dust mite (HDM) sensitivity [170; 171]. Other studies have shown that patients with AR displayed high levels of IL-33 and TSLP mRNA in the nasal epithelium [172; 173; 174].