Distinct Phenotypes of Peripheral Innate Lymphoid Cells and T Cells in Type 2 and Non‐Type 2 Asthma

ABSTRACT Background Investigation of T cell and innate lymphoid cell (ILC) subsets in type 2 (T2) and non‐type 2 (non‐T2) asthma are needed to elucidate disease mechanisms. In this study, we aimed to identify ILC, CD4+, and CD8+ T cell populations in blood that differentiate between T2 and non‐T2 features in subjects with and without asthma. Methods The study population included 86 young adults selected from the Swedish population‐based BAMSE cohort. Asthma and non‐asthma subjects with sensitization to inhalant allergens and/or blood eosinophil count ≥ 0.3 × 10 9 /L were classified into T2 groups. Non‐T2 groups were defined by the absence of sensitization to inhalant allergens and blood eosinophil count < 0.3 × 10 9 /L. PBMC samples underwent 18‐parameter flow cytometry to identify ILC and CD4+ and CD8+ T cell populations. Logistic regression models were employed on normalized flow cytometry data after hierarchical clustering. Results A higher frequency of CD4+ CRTH2+ T memory cells was associated with T2 features independent of asthma status. The frequency of CD62L+ ILC2s was higher and CD4+ KLRG1+ central memory T cells was lower specifically in T2 asthma. Non‐T2 asthma was associated with increased frequencies of CD45RO+ ILC2s and CD8+ memory T cells. Conclusion Our results suggest that T2 asthma and non‐T2 asthma are characterized by distinct features related to ILC and T cell populations. Further investigation of particularly ILC and CD8+ T cell subsets in non‐T2 asthma could offer a deeper understanding of underlying disease mechanisms for this endotype.