Mechanisms of Interplay Between Allergy and Viruses in Asthma

Inclusion criteria

Inclusion criteria

for Asthmatic subjects:

• Age 18-55 years
• Doctor diagnosis of Asthma
• Histamine PC20 < 8 µg/ml (or <12 µg/ml and bronchodilator response ≥ 12%) and worsening asthma symptoms with infection since last change in asthma therapy
• Atopic on skin testing
• Treatment comprising ICS or combination inhaler (LABA+ICS)

*subjects on inhaled corticosteroids must be on a daily dose of 400mcg fluticasone or equivalent.

• An Asthma Control Questionnaire (ACQ) score of > 0.75.

Inclusion criteria

for healthy controls:

• Age 18-55 years
• No history or clinical diagnosis of asthma
• No history of allergic rhinitis or eczema
• Negative responses on skin prick testing
• PC20 > 8 µg/ml and bronchodilator response <12%
• Absence of current or previous history of significant respiratory disease
• Absence of significant systemic disease

Exclusion criteria

Exclusion criteria

for Asthmatic subjects:

• Smoking history over past 6 months
• Negative skin prick tests
• Current symptoms of allergic rhinitis
• Current or previous history of significant respiratory disease (other than asthma)
• Any clinically relevant abnormality on screening or detected significant systemic disease
• Pregnant or breastfeeding women
• Contact with infants or elderly at home or at work
• Asthma exacerbation or viral illness within the previous 6 weeks
• Treatment with oral steroids now or in the previous 3 months
• Current use of nasal spray, anti-histamine, anti-leukotrienes
• Antibodies to rhinovirus 16 in a titre >1:2

Exclusion criteria

for healthy controls:

• Any clinically relevant abnormality on screening or detected significant systemic disease
• A current or previous diagnosis of asthma
• Any positive skin prick test
• Current symptoms of allergic rhinitis
• History of eczema or allergic rhinitis
• Pregnant or nursing women
• Common cold within the previous 8 weeks
• Treatment with oral or inhaled steroids now or in the previous 3 months; current use of long-acting β-agonists, nasal spray, anti-histamine, leukotrienes or tiotropium.
• Shortness of breath score at screening over 1 or total lower respiratory tract score over 7
• Antibodies to rhinovirus 16 in a titre >1:2