Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland.
Department of Anesthesia, Tampere University Hospital, Tampere, Finland.
J Breath Res. 2020 Nov 5;15(1):016008. doi: 10.1088/1752-7163/abc054.
Fractional exhaled nitric oxide (FNO) is a marker of airway inflammation. Measuring FNO at multiple flow rates enables calculation of NO parameters: bronchial NO output (J NO), bronchial wall (C NO) and alveolar (C NO) NO concentrations, and bronchial diffusion factor of NO (D NO). FNO is known to rapidly reduce after the commencement of inhaled corticosteroid (ICS) treatment. However, little is known on the effect of ICS on the other NO parameters. We assessed (1) the onset of action of ICS treatment on the NO parameters and (2) whether the changes in bronchial NO output are due to changes in bronchial wall NO concentration or diffusion factor. FNO and other NO parameters were measured at baseline and after 1, 3 and 7 d of treatment with inhaled fluticasone propionate 250 μg b.i.d. in 23 allergic children with a history of asthma-like symptoms. There was a decrease in J NO (from 680 (244/1791) (median (1st/3rd quartile)) to 357 (165/753) pl s, p < 0.001) and FNO( from 13.8 (7.5/35) to 8.3 (5.36/17.0) ppb, p < 0.001) in 3 d from the first dose of ICS. Also, C NO seemed to reduce after 3 d (from 171 (89/328) to 79 (54/157) ppb, p = 0.041), while D NO remained unchanged. Furthermore, C NO reduced during the 7 d treatment (from 3.0 (2.0/5.0) to 2.3 (1.9/2.6) ppb, p = 0.004). ICS treatment reduced FNO and J NO rapidly and the decline was caused by decreased bronchial wall NO concentration while bronchial NO diffusion factor remained unchanged. These findings suggest that C NO could be a more specific marker of airway inflammation and treatment response than J NO or FNO, which are both determined also by D NO that seems to be resistant to the treatment with ICS.
呼出气一氧化氮（FNO）是气道炎症的标志物。在多个流量下测量 FNO 可以计算出 NO 参数：支气管一氧化氮输出（JNO）、支气管壁（CNO）和肺泡（CNO）NO 浓度以及支气管 NO 扩散因子（DNO）。已知吸入皮质类固醇（ICS）治疗开始后，FNO 会迅速降低。然而，关于 ICS 对其他 NO 参数的影响知之甚少。我们评估了（1）ICS 治疗对 NO 参数的作用开始时间，以及（2）支气管一氧化氮输出的变化是否归因于支气管壁 NO 浓度或扩散因子的变化。在 23 名有哮喘样症状史的过敏性儿童中，在每天两次吸入丙酸氟替卡松 250μg 治疗的第 1、3 和 7 天，测量了 FNO 和其他 NO 参数。从第 1 次 ICS 剂量开始的 3 天内，JNO（从 680（244/1791）（中位数（1/3 四分位数））降至 357（165/753）pl s，p <0.001）和 FNO（从 13.8（7.5/35）降至 8.3（5.36/17.0）ppb，p <0.001）均降低。此外，CNO 似乎在 3 天后降低（从 171（89/328）降至 79（54/157）ppb，p=0.041），而 DNO 保持不变。此外，在 7 天的治疗过程中，CNO 降低（从 3.0（2.0/5.0）降至 2.3（1.9/2.6）ppb，p=0.004）。ICS 治疗迅速降低了 FNO 和 JNO，下降是由于支气管壁 NO 浓度降低所致，而支气管 NO 扩散因子保持不变。这些发现表明，与 JNO 或 FNO 相比，CNO 可能是气道炎症和治疗反应更特异的标志物，后者还受似乎对 ICS 治疗具有抗性的 DNO 决定。
