Allergen immunotherapy improves airway epithelial antiviral immunity in patients suffering from allergic asthma.

This double-blind randomized controlled trial (VITAL) was carried out to examine the impact of house dust mite-sublingual allergen immunotherapy (HDM-SLIT) on bronchial epithelial antiviral and inflammatory responses in allergic asthma-affected people.

HDM-SLIT 12-SQ or a placebo was administered to adult patients with asthma caused by a house dust mite allergy for 24 weeks. At baseline and week 24, a bronchoscopy was done and samples of human bronchial epithelial cells were taken.

At baseline and week 24, human bronchial epithelial cells were grown and activated using the viral mimic poly (I:C). Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was utilized for quantifying mRNA expression. Using multiplex ELISA, an estimation of protein levels was done.

Overall, 39 participants were randomly assigned to get either HDM-SLIT (n=20) or a placebo (n=19). With HDM-SLIT, elevated poly (I:C)-stimulated production of interferon (IFN)-β, both at the gene and protein levels was noted. Interleukin (IL)-33 expression tended to decrease, although IFN- λ gene expression was reported to increase. On the other hand, in the HDM-SLIT group, pro-inflammatory cytokines like tumor necrosis factor (TNF)- α and IL-6 raised from the baseline. No significant alterations in thymic stromal lymphopoietin, IL-4, IL-13, and IL-10 were witnessed.

The use of HDM-SLIT was associated with improvement in antiviral resistance of bronchial epithelial. These findings indicated HDM-SLIT's effectiveness in minimizing exacerbations in allergic asthma.