Standardising Nasal Allergen Challenge in Adult With Hay Fever

Summary

Hay fever affects 1 in 4 of the UK population and has significant effects on the quality of life of sufferers. Allergy to grass pollen is the most common cause. A detailed understanding of the mechanisms involved during allergic reactions to pollens in hay fever sufferers may provide improvements in diagnosis, drug treatment and assessment of their response to treatment.

Controlled exposures to allergens such as grass pollen can provide important information on the mechanisms of allergic inflammation and may be used to assess the success of anti-allergy treatments.

Nasal allergen challenge (NAC) is a useful tool in the investigation of allergic rhinitis, including grass pollen-induced seasonal allergic rhinitis (hay fever). NAC is performed by installation of a very small amount of grass pollen extract into the nose in order to reproduce mild and short-lived symptoms such as nasal itch, sneezing, runny nose and nasal congestion that you experience in a more severe form during natural exposure to grass pollen during the summer. Nasal allergen challenge has allowed us to explore the mechanism of hay fever and to provide a rapid and reliable method for investigating new potential treatments for hay fever.

Nasal allergen Challenge is a very well-standardised and safe procedure that has been performed within the department of Allergy and Clinical Immunology at Imperial College and Royal Brompton Hospital for many years.

Unfortunately the grass pollen extract ('Aquagen') that we have routinely used for nasal challenge has been discontinued and is therefore no longer available. The present study involves testing an alternative source of the grass pollen extract in the form of 'Grazax' which is a freeze-dried tablet that is highly standardised and should enable us to give an identical amount of grass pollen extract for the purpose of nasal challenge. We plan a 'head-to-head' comparison of the two extracts in nasal challenge in order to confirm that the two sources of allergen are equivalent thereby enabling us to use Grazax as the source of grass pollen extract for our nasal challenge studies in the future.

Conditions

• Allergic Rhinitis

Interventions

DIAGNOSTIC_TEST

Aquagen

To compare the clinical allergic response after direct installation of an aqueous solution of Aquagen Timothy Grass pollen extract via nasal allergen challenge with the clinical allergic response after direct installation of an aqueous solution of Grazax Timothy Grass lyophilisate tablets via nasal allergen challenge in grass pollen allergic individuals.

DIAGNOSTIC_TEST

Grazax

To compare the clinical allergic response after direct installation of an aqueous solution of Aquagen Timothy Grass pollen extract via nasal allergen challenge with the clinical allergic response after direct installation of an aqueous solution of Grazax Timothy Grass lyophilisate tablets via nasal allergen challenge in grass pollen allergic individuals.

Sponsors & Collaborators

• Imperial College London

  lead OTHER

Principal Investigators

• Prof Stephen Durham, MD · Imperial College London

Study Design

Allocation

RANDOMIZED

Purpose

DIAGNOSTIC

Masking

NONE

Model

CROSSOVER

Eligibility

Min Age

18 Years

Max Age

65 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2019-09-26

Primary Completion

2020-05-29

Completion

2020-08-28

Countries

• United Kingdom

Study Locations