After careful consideration, the American Academy of Allergy, Asthma & Immunology canceled its annual meeting that was to take place in Philadelphia, Pennsylvania from March 13 to 16, because of concerns regarding the coronavirus disease 2019 (COVID-19) outbreak. Although the live events will not proceed as planned, our readers can still find coverage of research that was scheduled to be presented at the meeting.
GATA3 group 2 innate lymphoid cells (ILC2s) may play a novel role in the pathogenesis of sputum eosinophilia in chronic obstructive pulmonary disease (COPD), according to study results intended to be presented at the Annual Meeting of the American Academy of Allergy, Asthma & Immunology (AAAAI).
Sputum eosinophilia may be a feature of COPD in addition to asthma. The objective of this study was to determine whether the presence of eosinophils in the sputum of patients with COPD was associated with the activation of elevated ILC2.
In this study, researchers recruited patients with COPD (n=20) and healthy control individuals (n=16) from clinics at the University of California, Davis. Sputum was induced in all participants, and peripheral blood samples were taken. Sputum eosinophilia was measured by differential cell count, and transcription factor and cytokine expression of ILCs were measured by flow cytometry in blood and sputum. Group 1 ILCs (ILC1s) were defined as T-bet, ILC2s as GATA3, and group 3 ILCs (ILC3s) as RORγt.
Eosinophils were elevated in the sputum of patients with COPD compared with healthy control individuals (1.72±0.5% vs 0.08±0.06%; P =.0003). In addition, ILC2s/mL sputum levels were significantly higher in patients with COPD vs the control group (864±238 vs 127±44; P =.004). No difference in ILC1s or ILC3s/mL sputum was observed between the control group and patients with COPD. The presence of eosinophils in the sputum positively correlated with ILC2s (r=0.846).
The researchers concluded that ILC2s are associated with the pathogenesis of sputum eosinophilia in COPD.
Flayer, C, Linderholm A, Franzi L, et al. Sputum ILC2s are increased in COPD subjects with eosinophils. J Allergy Clin Immunol. 2020;145(Suppl 2):AB14.
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