Decrease in CD38⁺ TH2A cell frequencies following immunotherapy with house dust mite tablet correlates with humoral...

Area of Science:

• Immunology
• Allergy Research
• Cellular Immunology

Background:

• Pathogenic TH2A cells are implicated in seasonal allergies.
• Previous studies showed decreased TH2A cells after multi-food immunotherapy in food-allergic individuals.
• This study investigates TH2A cell changes during house dust mite immunotherapy (HDM-AIT).

Purpose of the Study:

• To confirm the decline of TH2A cells in patients undergoing HDM-AIT.
• To examine the subset of CD38 expressing activated TH2A cells.
• To explore the relationship between cellular and humoral immune responses during HDM-AIT.

Main Methods:

• Flow cytometry was used to analyze TH2A and CD38+ TH2A cell frequencies in 182 Japanese HDM-allergic individuals over a 1-year clinical trial.
• The study assessed the efficacy of HDM tablets.
• Interrelationships between cellular responses and mite-specific IgE and IgG4 levels were investigated.

Main Results:

• TH2A cell frequencies decreased in both active and placebo groups.
• CD38+ TH2A cell frequencies significantly decreased only in the active HDM-AIT groups.
• In younger individuals (16-30 years), both TH2A and CD38+ TH2A cells were significantly reduced in active groups.
• Inverse correlations were found between TH2A/CD38+ TH2A cell changes and IgG4 antibody levels.

Conclusions:

• Monitoring TH2A cell frequencies is valuable for assessing immunotherapy efficacy in allergic individuals, including those with perennial HDM allergy.
• CD38 expression helps identify the specific TH2A cell subset modulated by AIT.
• Correlated cellular and humoral responses highlight coordinated adaptive immune pathways during AIT.