The Global Initiative for Asthma (GINA) report has directed clinical guidelines for asthma since 2014. Evidence comes from randomised controlled trials, but not from real-world or observational studies, which could be a limitation [1].
Asthma is a heterogeneous condition with distinct underlying pathophysiology and treatment response [2]. Biomarkers help predict treatment response, such as fractional exhaled nitric oxide (FeNO) [3], for which devices for quick and non-invasive measurement are being developed [4]. Blood eosinophil (B-Eos) count has gained increasing interest as a biomarker as well [5]. While often concomitant, FeNO and B-Eos typically represent different aspects of the type 2 inflammatory pathway [3]. The latest 2019 GINA report does not incorporate biomarkers into their recommendations, but does adopt lung function measurements into all guidelines [6], which are of little use in distinguishing between asthma phenotypes [1].
The National Institute for Health and Care Excellence (NICE) in the United Kingdom developed guidelines for asthma based on both real-world and observational studies as well as randomised controlled trials, in which they identified FeNO as an important measurement [7]. Thus, NICE and GINA have come to substantially different conclusions with regard to the utility of FeNO in clinical practice [1] (See Table).
The authors conclude that there is a growing need for clinical biomarkers to better stratify asthma patients according to their inflammatory phenotype or endotype [1]. They hope that the contrasting guidelines will stimulate further clinical research and additional real-world studies on the use of biomarkers and lead to consistent advice for clinicians managing asthma. FeNO measurement shows promise in the diagnosis and management of asthma alone and in combination with B‐Eos count [4,8]. To enable adequate inclusion of biomarkers in asthma guidelines for the broad benefit of patients and society, guidelines should consider all available evidence, including both real‐world evidence and randomised controlled trials [1].
References:
- Alving K, Diamant Z, Lucas S, et al. Point‐of‐care biomarkers in asthma management: Time to move forward Allergy. Allergy. 2020;75(4):995‐997.
- Diamant Z, Vijverberg S, Alving K, et al. Towards clinically applicable biomarkers for asthma ‐ an EAACI position paper. Allergy. 2019; 74(10):1835-1851.
- Alving K, Malinovschi A. Basic aspects of exhaled nitric oxide. Eur Respir Monograph. 2010;49:1‐31.
- Bjermer L, Alving K, Diamant Z, et al. Current evidence and future research needs for FeNO measurement in respiratory diseases. Respir Med. 2014;108(6):830‐841.
- Hambleton K, Connolly CM, Borg C, et al. Comparison of the peripheral blood eosinophil count using near‐patient testing and standard automated laboratory measurement in healthy, asthmatic and COPD subjects. Int J Chron Obstruct Pulmon Dis. 2017;12:2771‐27
- Global Initiative for Asthma, 2019. https://ginasthma.org/gina-reports
- National Institute for Health and Care Excellence, 2017. Asthma: diagnosis, monitoring and chronic asthma management. NICE Guideline [NG80] https://www.nice.org.uk/guidance/ng80
- Smith AD, Cowan JO, Brassett KP, et al. Exhaled nitric oxide: a predictor of steroid response. Am J Respir Crit Care Med. 2005;172(4):453‐459.