Leena Jalota1,2, D Richard Allison1,2,3, Vinisha Prajapati1,2, Jose J Vempilly1,2, Vipul V Jain4,5,6,7. 1. Division of Pulmonary and Critical Care, University of California, San Francisco-Fresno, 155 N Fresno St, Fresno, CA, 93701, USA. 2. Department of Internal Medicine, University of California, San Francisco-Fresno, 155 N Fresno St, Fresno, CA, 93701, USA. 3. Community Regional Medical Center, Fresno, CA, USA. 4. Division of Pulmonary and Critical Care, University of California, San Francisco-Fresno, 155 N Fresno St, Fresno, CA, 93701, USA. vjain@fresno.ucsf.edu. 5. Department of Internal Medicine, University of California, San Francisco-Fresno, 155 N Fresno St, Fresno, CA, 93701, USA. vjain@fresno.ucsf.edu. 6. Community Regional Medical Center, Fresno, CA, USA. vjain@fresno.ucsf.edu. 7. Chronic Lung Disease Program, University of California, San Francisco, Fresno, 2823, Fresno St, Suite A, Fresno, CA, 93721, USA. vjain@fresno.ucsf.edu.
Abstract
OBJECTIVE: Fraction of exhaled nitric oxide (FENO) has been proposed as a non-invasive biomarker for allergic inflammation seen in asthma. Many asthmatics in clinical practice have never had spirometry and recent data report misdiagnoses in patients with physician diagnosed (PD) asthma. The aim of this study was to assess the ability of FENO to discriminate between those with and without airflow obstruction (AO) among patients with PD-asthma. METHODS: Frequent exacerbators of PD-asthma (with 2 or more asthma exacerbations leading to emergency room visit or hospitalization within last 12 months) were enrolled. All patients underwent diagnostic evaluations including spirometry, FENO testing and serum immunoglobulin (IgE) and eosinophils. Serial spirometry and methacholine challenge testing (MCT) were performed as indicated. AO was defined by a decreased FEV1/FVC ratio (< 70% and/or < LLN), or a positive MCT. RESULTS: Of the 222 patients with PD-asthma, AO was found in 136 (vs. 86 without AO). 81.6% of patients with AO and 66.2% without AO completed FENO testing. There was no significant difference in the mean FENO levels among patients with or without AO (40.8 vs. 30.4 ppb, P = 0.10). Likewise, there was no difference in the serum IgE levels and serum eosinophils. CONCLUSIONS: Our analyses suggest that FENO levels do not help discriminate between those with and without AO in patients with PD-asthma. Patients who experience symptoms of asthma may have elevated FENO levels above the suggested cut points of 20-25 ppb. Objective confirmation of AO should be considered in all patients with PD-asthma, irrespective of FENO levels.
OBJECTIVE: Fraction of exhaled nitric oxide (FENO) has been proposed as a non-invasive biomarker for allergic inflammation seen in asthma. Many asthmatics in clinical practice have never had spirometry and recent data report misdiagnoses in patients with physician diagnosed (PD) asthma. The aim of this study was to assess the ability of FENO to discriminate between those with and without airflow obstruction (AO) among patients with PD-asthma. METHODS: Frequent exacerbators of PD-asthma (with 2 or more asthma exacerbations leading to emergency room visit or hospitalization within last 12 months) were enrolled. All patients underwent diagnostic evaluations including spirometry, FENO testing and serum immunoglobulin (IgE) and eosinophils. Serial spirometry and methacholine challenge testing (MCT) were performed as indicated. AO was defined by a decreased FEV1/FVC ratio (< 70% and/or < LLN), or a positive MCT. RESULTS: Of the 222 patients with PD-asthma, AO was found in 136 (vs. 86 without AO). 81.6% of patients with AO and 66.2% without AO completed FENO testing. There was no significant difference in the mean FENO levels among patients with or without AO (40.8 vs. 30.4 ppb, P = 0.10). Likewise, there was no difference in the serum IgE levels and serum eosinophils. CONCLUSIONS: Our analyses suggest that FENO levels do not help discriminate between those with and without AO in patients with PD-asthma. Patients who experience symptoms of asthma may have elevated FENO levels above the suggested cut points of 20-25 ppb. Objective confirmation of AO should be considered in all patients with PD-asthma, irrespective of FENO levels.
Authors: Vipul V Jain; Richard Allison; Sandra J Beck; Ratnali Jain; Paul K Mills; James W McCurley; Karl P Van Gundy; Michael W Peterson Journal: Respir Med Date: 2014-09-28 Impact factor: 3.415
Authors: Kian Fan Chung; Sally E Wenzel; Jan L Brozek; Andrew Bush; Mario Castro; Peter J Sterk; Ian M Adcock; Eric D Bateman; Elisabeth H Bel; Eugene R Bleecker; Louis-Philippe Boulet; Christopher Brightling; Pascal Chanez; Sven-Erik Dahlen; Ratko Djukanovic; Urs Frey; Mina Gaga; Peter Gibson; Qutayba Hamid; Nizar N Jajour; Thais Mauad; Ronald L Sorkness; W Gerald Teague Journal: Eur Respir J Date: 2013-12-12 Impact factor: 16.671