Effect of Aspirin Challenge on Innate Lymphoid Cells in Asthma Patients With Aspirin Hypersensitivity

Previous studies confirmed increased group 2 innate lymphoid cell (ILC2s) count in nasal scrapings, alongside a reduced blood ILC2 count, in patients with nonsteroidal anti-inflammatory drug-exacerbated respiratory disease (N-ERD) after intranasal administration of cyclooxygenase-1 inhibitors. This study aimed to assess the role of blood and sputum ILCs in N-ERD patients during oral aspirin-induced bronchospasm and to compare patients with eosinophilic and noneosinophilic airway inflammatory phenotypes of asthma. Induced sputum, blood, and urine samples were collected in 24 patients with confirmed N-ERD at baseline and during aspirin-induced bronchospasm. Sputum and blood ILC counts were evaluated using flow cytometry. There was a significant increase in blood ILC1 count (p < 0.001) and percentage (p = 0.003) during aspirin-induced bronchospasm. No significant changes in sputum ILCs were observed, but the number of detected ILCs was very low. There was a significant reduction in induced sputum supernatant (ISS) levels of prostaglandins PGE₂ (p = 0.004) and PGD₂ (p = 0.045), leukotriene B₄ (p = 0.045), and 15-oxo-eicosatetraenoic acid (p = 0.045) during aspirin-induced bronchospasm. Blood ILC1 count is increased during oral aspirin-induced bronchospasm in patients with N-ERD, but sputum ILC count at baseline is very low. Therefore, no reliable changes in sputum ILC counts can be detected during bronchospasm.