Acinar effect of inhaled steroids evidenced by exhaled nitric oxide

作者：Van Muylem Alain^*; Kerckx Yannick; Michils Alain

来源：Journal of Allergy and Clinical Immunology, 2010, 126(4): 730-U93.

DOI：10.1016/j.jaci.2010.06.019

• Exhaled nitric oxide
• alveolar nitric oxide
• asthma
• inhaled corticosteroids
• Asthma Control Questionnaire

Background: The effects of inhaled corticosteroids (ICSs) on distal lung inflammation, as assessed by alveolar nitric oxide concentration (C(A)NO), are a matter of debate. Recently, a theoretic study suggested that acinar airway obstruction that is relieved by ICS treatment and associated with a decrease in fraction of exhaled nitric oxide (FeNO) concentration might, paradoxically, increase C(A)NO. This increase could be a hallmark effect of ICSs at the acinar level.
Objective: In the light of this new hypothesis, we studied changes in C(A)NO and FeNO after administration of ICSs.
Methods: C(A)NO and FeNO were measured before and after ICS treatment of 38 steroid-naive patients with uncontrolled asthma who showed clinical improvement after ICS therapy.
Results: The average FeNO decreased from 78.3 to 28.9 ppb (P < .001); CANO decreased from 7.7 to 4.3 ppb (P = .009). In 14 subjects (low-slope group), slope (= Delta C(A)NO/Delta FeNO) values (Delta = post-ICS - pre-ICS value) were less than the 95% normal CI (average Delta FeNO = -32.7 ppb and average Delta C(A)NO= +2.9 ppb). In this group, baseline C(A)NO was abnormally low when FeNO was taken into account. In 11 subjects (the high-slope group), the slope was above the normal interval (average Delta FeNO = -42.5 ppb and average Delta C(A)NO = -14.7 ppb).
Conclusion: Opposite patterns (one that was predicted) can indicate peripheral actions of ICSs; this difference might account for conflicting data reported from studies using C(A)NO to determine the peripheral action of ICSs. We show that a low C(A)NO does not preclude distal inflammation. (J Allergy Clin Immunol 2010;126:730-5.)

• 出版日期2010-10