Peripheral pathological ILC2: An inflammatory indicator for the assessment of asthma control in clinics

Background: A newly-discovered type 2 innate lymphoid cell (ILC2), which acted as an early source of Th2 cytokines such as IL-5/IL-13 has been found involved in the pathogenesis of asthma. In this study, we will investigate the correlation between pathological ILC2s and asthma clinical characteristics . Methods: A total of 42 persistent asthma and 26 healthy subjects were enrolled in this study. Frequency of IL-13 + ILC2 in the groups of asthmatics and healthy donors were checked by FACS . Sorted ILC2s were stimulated with IL-25 plus IL-33 in different time points, cytokine profiles were checked by multiplex ELISA; Correlation between IL-13 + ILC2 and varied clinical data were analyzed. Measurements and Main Results: Human ILC2s were identified successfully as Lin - CD45 high IL-7R + CRTH2 + cells, the percentages of ILC2s were 0.022±0.016% in asthmatics and 0.016±0.007% in healthy donors respectively. Percentages of IL-13 + ILC2 were significantly higher in PBMCs of poorly-controlled group (53.1±16.3%) or part-control group (37.9+11.7) than well-controlled group (17.9±6.33%) and healthy controls group (18.2±9.4%) (p + ILC2) was positively correlated with asthma control systems (R 2 =0.56, 0.62 respectively; p Conclusions: ILC2 not PBMC, produce huge amount of Th2-like cytokines (IL-5, IL-13) which have been proved to involve in the pathogenesis of asthma. The frequency of pathological ILC2 (IL-13 + ILC2) was positively correlated with the control status of asthma which has the potential to be an objective indicator for assessing asthma control in the future.