Elevated Proportions of Circulating CXCR5+ Follicular Helper T Cells Reflect the Presence of Airway Obstruction in Asthma.

Materials and Methods: Using flow cytometry, we identified and quantified Group 2 innate lymphocytes, T helper 2 cells, follicular helper T cells, and T helper 17 cells in peripheral blood samples from 49 individuals with asthma. We then conducted cross-sectional analyses to assess relationships between levels of these immune cells and lung function parameters, including the percentage predicted forced expiratory volume in 1 s (%FEV1). We also examined correlations between the proportions of immune cells and type 2 biomarkers. Results: Proportions of CXCR5+ follicular helper T cells in human peripheral blood, as opposed to Group 2 innate lymphoid cells (ILC2) or T helper 2 cells, were significantly higher in cases with %FEV1 < 80% compared to those with %FEV1 ≥ 80%. Further, these proportions correlated negatively with %FEV1 and positively with blood eosinophil counts. Conclusions: The proportion of circulating follicular helper T cells, but not T helper 2 cells or Group 2 innate lymphoid cells, may reflect the presence of airway obstruction caused by persistent type 2 inflammation.

Lung CCR6-CXCR3- type 2 helper T cells as an indicator of progressive fibrosing interstitial lung diseases.

Progressive fibrosing interstitial lung diseases (PF-ILDs) have a poor prognosis and may be resistant to corticosteroids and/or immunosuppressants, but antifibrotic therapies such as nintedanib and pirfenidone have been shown to slow the deterioration of lung function. The aim of this study was to identify the characteristic cellular profile of bronchoalveolar lavage fluid at diagnostic bronchoscopy for predicting PF-ILDs, defined as fibrotic diseases on chest high-resolution computed tomography with more than a 5% relative decline in the percent predicted value of forced vital capacity (FVC) over 6 months. The proportions of inflammatory cells, CCR6-CXCR3- T helper type 2 (Th2) cells among conventional CD4+ T cells in bronchoalveolar lavage fluid (BALF) and peripheral blood, were measured by flowcytometry. The proportion of lymphocytes in BALF was significantly higher in non-PF-ILD patients than in PF-ILD patients. The proportion of Th2 cells in BALF, but not in peripheral blood, was significantly higher in PF-ILD patients than in non-PF-ILD patients. Multivariate analysis showed that a greater population of Th2 cells in BALF was the only indicator for PF-ILDs. An increased proportion of Th2 cells in BALF is associated with greater deterioration of lung function in fibrotic interstitial lung diseases.