Local nasal immunotherapy for allergic rhinitis: A systematic review and meta‐analysis

Abstract

Introduction Local nasal immunotherapy (LNIT), an alternative noninjection immunotherapy method, is theoretically an efficient method for inducing immunotolerance directly in the affected organ. LNIT is more convenient and less invasive than injection immunotherapy, with fewer systemic reactions. The development of adjuvants to overcome LNIT's limitations raises the possibility of it being an alternative allergen immunotherapy. Objectives To evaluate the clinical and immunological efficacy and safety of LNIT for patients with allergic rhinitis. Methods A systematic search for randomized controlled trials comparing LNIT and placebo was performed using OVID Medline and Embase. Outcomes were total nasal symptom score (TNSS), symptom–medication score (SMS), medication score, immunological assessment, and nasal provocation threshold. Data were pooled for meta‐analysis. Results A total of 20 studies with 698 participants were included. The LNIT group had greater posttreatment improvement in TNSS, SMS, and medication score than control (TNSS: standardized mean difference [SMD], –1.37 [95% confidence interval [CI], –2.04 to –0.69]; SMS: SMD, –1.55 [95% CI, –2.83 to –0.28]; and medication score: SMD, –1.09 [95% CI, –1.35 to –0.83]). Immunological assessments showed no significant differences in serum‐specific IgE (mean difference [MD], 6.35; 95% CI, –4.62 to 17.31), nasal IgE (MD, –0.59; 95% CI, –1.99 to 0.81), or nasal eosinophil cationic protein (MD, 7.63; 95% CI, –18.65 to 33.91). Only serum IgG significantly increased with LNIT (MD, 0.45; 95% CI, 0.20, 0.70). Posttreatment, nasal provocation threshold was higher with LNIT (MD, 27.30; 95% CI, 10.13–44.46). No significant adverse events were reported. Conclusions LNIT is a safe alternative allergen immunotherapy route without significant adverse events. It improves clinical symptoms, reduces medication usage, and increases the nasal provocation threshold.

The Impact of Eosinophil Cationic Protein on Nasal Epithelial Cells: An Investigation of Cellular Responses

“…The cytokines and mediators released by these in ammatory cells can further activate and attract other in ammatory cells, forming a cycle of in ammation. [7,8] 2 Damage to mucosal epithelial cells: IL-8 can act as a signal molecule to activate in ammatory cells such as neutrophils, causing them to release various substances such as extracellular matrix enzymes, which damage nasal mucosal epithelial cells and aggravate the in ammatory reaction and allergic symptoms.…”

Allergen Specific Immunotherapy (AIT)

“…Recent advances in intranasal drug delivery systems warrant re-examination of LNIT as a viable option for the treatment of the allergic airway disease [111]. In a recent review and meta-analysis by Kasemsuk N et al (2022), after analyzing 20 studies involving 698 participants, the authors concluded that the LNIT group exhibited greater posttreatment improvements in the total nasal symptom score (TNSS), symptom-medication score (SMS), and medication score compared to the control (placebo) group [112], important parameters to be evaluated for, in general, determining efficacy of AIT.…”

The Present and Future of Allergen Immunotherapy in Personalized Medicine

“…Moreover, new routes of administration are currently being researched, which could perform a new impact on meeting patients’ needs and prerogatives, improving the adherence to therapy; however, they still require more detailed studies. Intralimphatic immunotherapy (ILIT), for example, may result in a reduction in the frequency of administration; epicutaneous immunotherapy (EPIT) may open new scenarios for the treatment of food allergy especially in children [ 41 ], and the anti-inflammatory effect of local nasal immunotherapy (LNIT) with FIP-fve peptide and denatured mite Tyrophagus putrescentiae may be exploited for the treatment of airway allergic diseases [ 42 , 43 ] ( Figure 1 ).…”