Alteration of circulating type 2 follicular helper T cells and regulatory B cells underlies the comorbid association of allergic rhinitis with bronchial asthma

- Tfh2 skewing within blood Tfh cell subsets occurs in AR and AR + Asthma cases.
- The %Breg cells are decreased during disease progression from AR to AR + Asthma.
- FeNO and eosinophil levels are correlated with index %Tfh2 cells per %Breg cells.
- Decreased %Breg cells under Tfh2 skewing are exaggerating factors of AR to asthma.

Allergic rhinitis (AR), the most common allergic disorder of the airway, is often accompanied by bronchial asthma. However, little is known about the mechanism by which AR advances to AR comorbid with bronchial asthma (AR + Asthma). To determine the pathophysiologic features of AR and AR + Asthma, we examined subsets of follicular helper T (Tfh) cells and regulatory B (Breg) cells in peripheral blood from AR and AR + Asthma patients. The results showed polarization of Tfh2 cells within Tfh cell subsets in both AR and AR + Asthma cases. Interestingly, the %Breg cells in total B cells were decreased in AR cases and, more extensively, in AR + Asthma cases. Moreover, we found significant correlations of fractional exhaled nitric oxide and blood eosinophil levels with the index %Tfh2 cells per %Breg cells. Our findings indicate that relative decrease in Breg cells under the condition of Tfh2 cell skewing is a putative exaggerating factor of AR to bronchial asthma.