Leaving GSK Pro

You are leaving GSK Pro to visit a separate website not associated with GSK Pro, a portal for US Healthcare Professionals.There are website links to third-party sites on GSK Pro. GSK is not responsible for content on third-party websites.




Two sides to the eosinophil story

Role of eosinophils in maintaining health includes1:

  • Regulating the immune system
  • Tissue regeneration and repair
  • Host protection (eg, defending against parasitic infection)

Too many airway tissue eosinophils in patients with severe asthma* is associated with2,3:

  • Increased symptoms
  • Greater likelihood for exacerbations
  • Airway inflammation
  1. *According to the American Thoracic Society (ATS) and European Respiratory Society (ERS), severe asthma is a type of asthma that requires treatment with high-dose inhaled corticosteroids (ICS), plus a second controller and/or systemic corticosteroid to prevent it from becoming uncontrolled, or asthma that remains uncontrolled despite this therapy.4


It's time to target treatment of severe asthma

~50% of patients with severe asthma have persistent airway tissue eosinophils.2

It's time to target treatment of severe asthma

~50% of patients with severe asthma have persistent airway tissue eosinophils.2

Confidently identify the right patients for NUCALA

Confidently identify the right patients for NUCALA


In patients 12 years and older with severe asthma and:

2 or more controller therapies, including high-dose ICS and an additional controller(s)

2 or more exacerbations in the previous 12 months and/or daily OCS


Blood eosinophils:

Conduct a complete blood count (CBC) with differential5


Baseline blood eosinophils ≥150 cells/μL are predictive of efficacy for NUCALA

  1. Exacerbations of asthma were defined as the worsening of asthma that required use of oral/systemic corticosteroids and/or hospitalization and/or emergency department (ED) visits; for patients on maintenance oral/systemic corticosteroids, exacerbations were defined as requiring at least double the existing maintenance dose for at least 3 days.

Blood Eosinophil Unit Conversion Calculator

If you receive lab results that are not expressed as cells/μL, use the calculator below to convert these results.


  1. Weller PF, Spencer LA. Functions of tissue-resident eosinophils. Nat Rev Immunol. 2017;17:746-757.
  2. Wenzel S. Severe asthma in adults. Am J Respir Crit Care Med. 2005;172(2):149-160.
  3. Malinovschi A, Fonseca JA, Jacinto T, Alving K, Janson C. Exhaled nitric oxide levels and blood eosinophil counts independently associate with wheeze and asthma events in National Health and Nutrition Examination Survey subjects. J Allergy Clin Immunol. 2013;132(4):821-827 e5.
  4. Chung KF, Wenzel SE, Brozek JL, et al. International ERS/ATS guidelines on definition, evaluation and treatment of severe asthma. Eur Respir J. 2014;43:343-373.
  5. Wagener AH, de Nijs SB, Lutter R, et al. External validation of blood eosinophils, FeNO and serum periostin as surrogates for sputum eosinophils in asthma. Thorax. 2015;70(2):115-120.