Recent developments in immunotherapy approaches for allergic rhinitis

Table 1 Factors affecting allergic rhinitis

No.	Risk/protective factor(s)	Details
1	Environmental factors	Many potential environmental risk factors, protective factors, and biomarkers of AR have been published. Tic disorders (class I), early-life antibiotic use, exposure to indoor dampness, acetaminophen exposure, childhood acid suppressant use, and exposure to indoor mold were environmental risk factors (class II), and coronavirus disease 2019 and prolonged breastfeeding were environmental protective factors (class II). The biomarkers graded as suggestive evidence were nasal nitric oxide in AR patients (class II) and interleukin-13 rs20541 polymorphism in AR patients (class III)[23]
2	Age (> 40 years old)	Age > 40 is an independent risk factor for AR combined with asthma[20]
3	Demographic factors	Smoking, drinking habits, and pet adoption are demographic factors affecting the presentation of AR[24]
4	Male	Being male is a risk factor for AR[19]
5	Family history	A family history of asthma or allergy is an independent risk factor for AR[19,20]
6	Allergic reactions	Adverse food reactions and mold allergies are independent risk factors for AR[20]
7	Air purifier use	The use of air purifiers is associated with AR risk[19]
8	Environmental exposure	Exposure to dust is a risk factor for AR[19]
9	Living location	Living in towns or urban areas is associated with AR risk[19]
10	Trends in prevalence	Trends in the prevalence of current AR and factors affecting symptoms have been documented. The prevalence of cumulative AR and current AR symptoms (AR in the past 12 mo) in 6-12-year-old children increased significantly. Longlasting disease before the appearance of the allergy significantly increases the risk of the development of cumulative AR[14]

AR: Allergic rhinitis.

Table 2 Distinct regional characteristics of allergic rhinitis

Region	Allergens
Thailand	Rice, corn, sorghum, and para grass
Southeast Asian Chinese population	Fungus
Tropical regions	Aedes aegypti
China
Xinjiang	Herbaceous allergens
Inner Mongolia	Artemisia pollen
Ningxia	Mugwort
Shenzhen	Brucella tropicalis, house dust mite, Dermatophagoides farinae, cockroach, and ragweed
Beijing	Ragweed and juniper pollen

Table 3 Comparison of different immunotherapies for allergic rhinitis

Method	Delivery route	Mechanism	Safety
SCIT	Subcutaneous (systemic) injection	IgG4 antibody induction[41]	Higher rates of systemic reactions[40]
SLIT	Sublingual (local) administration	IgA antibody induction[41]	Fewer systemic reactions than SCIT[40]
OIT	Oral cavity/gastrointestinal tract	Suppression of allergen-specific T-cell proliferation[50]	Oral pruritus[53]
ILIT	Lymph nodes	IgG4 antibody induction[54]	Safer than SCIT[58]
GIASIT	Intravenous infusion	Increased plasma gelsolin levels[59]	Mild side effects[59]
Combination of AIT and monoclonal antibody therapy	Subcutaneous monoclonal antibody and AIT route	Omalizumab (anti-IgE). Dupilumab (anti-IL4Rα). Tezepelumab (anti-TSLP)[62-64]	Mild or moderate application-site reactions[63]

Ig: Immunoglobulin; SCIT: Subcutaneous immunotherapy; SLIT: Sublingual immunotherapy; OIT: Oral immunotherapy; ILIT: Intralymphatic immunotherapy; GIASIT: Gold-induced autologous serum injection therapy; AIT: Allergen immunotherapy; TSLP: Thymic stromal lymphopoietin.

Table 4 Limitations of immunotherapy for allergic rhinitis

Limitation	Details	Resolution
Poor compliance with immunotherapy, which is related to gender and the number of diseases	Self-conscious inconvenience and unsatisfactory treatment effect, the compliance of children is better than that of adults	Patient education
Current SLIT guidelines are of average quality		The formulation methods and reporting standards of these guidelines must be formulated

SLIT: Sublingual immunotherapy.