Lokales IgE bei Patienten mit allergischer und nicht-allergischer Rhinitis

Allergic rhinitis (AR) is one of the most common chronic respiratory diseases and affects around 500 million people worldwide. However, in some of the patients experiencing rhinitis symptoms, the conventional tests do not show any evidence of allergen sensitization. In the past, these patients were often assigned to the non-allergic rhinitis (NAR) group, affecting over 200 million people worldwide. Over the past two decades, local allergic rhinitis (LAR) has emerged as an important differential diagnosis to NAR or idiopathic rhinitis (IR). Some authors postulate that up to a quarter of patients suffering from chronic rhinitis could in reality be affected by LAR and up to 62.5% of patients previously classified as NAR or IR could have LAR. LAR is defined by allergy-suggestive rhinitis symptoms, a positive reaction in nasal provocation tests (NPT) with aeroallergens and the occasional presence of specific antibodies in the nasal mucosa without any evidence of systemic sensitization being found. Since there is wide variation in LAR prevalence data, the aim of this work was to find out its prevalence in individuals with perennial rhinitis and to examine the nasal mucosa for local specific IgE (sIgE). For this purpose, 63 out of a group of 156 volunteers were examined in more detail. Twenty-one patients with perennial NAR were chosen, examined and their results were compared to those of 24 patients with AR and house dust mite (HDM) allergy, and 18 controls. We examined the severity of their clinical symptoms, their skin prick test reaction, total IgE and sIgE against the house dust mite species Dermatophagoides pteronyssinus (D1) and Dermatophagoides farinae (D2) in serum and nasal secretions (NS) and performed an NPT with D2. NPT was assessed using peak nasal inspiratory flow (PNIF) measurement and Lebel symptom score. While the severity of clinical symptoms of NAR and AR patients was very similar, none of the NAR patients demonstrated nasal sIgE against HDM or a positive reaction in NPT against D2. The median nose sum score for both AR and NAR patients was 11 of 24 points (range: 6–21 points and 6–20 points, respectively) and was significantly different from that of controls, who had a score of 0 points (range: 0–5 points). The median sIgE-D1 and sIgE-D2 in NS was 0.1 kU/L (range: 0.1–0.1 kU/L) in both NAR patients and controls and was not significantly different from each other. In contrast, 94.12 % of the AR samples examined showed elevated sIgE-D1 or sIgE-D2 levels in NS. The median concentration in NS of AR patients was 1.19 kU/L for sIgE-D1 (range: 0.1–14.93 kU/L) and 2.34 kU/L for sIgE-D2 (range: 0.1–22.14 kU/L). The NPT with D2 was positive in 13/14 AR patients (= 92.86 %) and none of the NAR patients or controls. Both absolute and percentage PNIF reduction after HDM provocation differed significantly between AR patients and controls as well as between patients with AR and NAR. The percentage PNIF reduction after HDM provocation was 55.85 % in the AR group, 7.14 % in the NAR group, and 0 % in controls. However, there was no significant difference between controls and NAR patients. Based on these results, we could only detect positive NPTs and nasal sIgE against HDM species in the AR group. Thus, we conclude a prevalence for LAR among NAR patients of 0 % for this study. Therefore, in summary of our findings, we assume that the prevalence of LAR among NAR or IR patients in the studied population living in Germany must be lower than previously reported in other populations.